Provided by: impressive_0.13.1-1.1_all bug

NAME

       Impressive - presentation tool with eye candy

SYNOPSIS

       impressive [OPTIONS...] FILES...

DESCRIPTION

       Impressive  is  a  simple  presentation program that displays slideshows of PDF documents, image files or
       video files. Rendering is done via OpenGL, which allows for some "eye candy" effects.

       A somewhat-modern GPU (graphics processing unit) supporting OpenGL 2.0 or OpenGL ES 2.0  and  appropriate
       drivers are required to run Impressive.

OPTIONS

       -a <seconds> or --auto <seconds>
              Automatically  advance  to  the  next page after the given number of seconds. Together with the -w
              option (described below), this can be used to create automatic slideshows.
              Note that this option will not interrupt video playback: If a video is longer  than  the  interval
              specified  with  --auto,  it  will be played until the end, but Impressive will change to the next
              page directly after that.

       -A <X>:<Y> or --aspect <X>:<Y>
              Specifies the display aspect ratio. Normally, Impressive assumes that the pixel  aspect  ratio  is
              1:1  (square  pixels),  regardless of the display resolution that has been set up. If a resolution
              has been selected that doesn't match the display's aspect ratio, the screen will be distorted.  To
              overcome  this,  this  option  may  be used to manually specify the display aspect ratio, e.g. "-A
              16:9". Note that this option has no effect if the MuPDF backend is used for rendering.

       -b or --noback
              Disables background rendering. By default, Impressive will pre-render  all  pages  in  a  separate
              background thread while the presentation runs. If this option is specified, it will instead render
              all  pages immediately on startup. This option has no effect if caching is disabled (--cache none,
              see below).

       --background <color>
              Sets the background color of the overview page and the page border that's visible  if  the  page's
              and the screen's aspect ratios don't match.
              The  color  is specified using HTML/CSS 3-digit or 6-digit hexadecimal RGB syntax: #f00 or #ff0000
              is bright red, for example. The leading hash sign (#) is optional. In addition,  the  words  black
              (which is also the default) and white are recognized.

       -bare
              Disables  all  functionality  that  relies on temporary files, specifically video frame extraction
              using MPlayer (extracting video frames with FFmpeg still works), PDF page  title  extraction,  PDF
              hyperlinks,  and  even  PDF  rendering  for  all  backends  except MuPDF 1.4 or newer on Unix-like
              operating systems.

       --box-edge <pixels>
              Sets the border size (in pixels when unzoomed) of the  highlight  boxes'  and  spotlight's  smooth
              edges. The default value is 4 pixels; it can be set to zero, in which case highlight boxes and the
              spotlight will have hard edges.

       -B <ms> or --boxfade <ms>
              Sets  the  duration  (in  milliseconds)  of  the highlight box fade-in/fade-out animation. Default
              value: 100 ms.

       -c <mode> or --cache <mode>
              Specifies the page cache mode to use. Valid options are:
              none
                     Disables page caching altogether, only the current and the following page will be  kept  in
                     RAM.  Jumping  between  pages will be very slow, because Impressive will need to render the
                     requested pages on the fly. In addition, the overview page won't be  complete  until  every
                     page has been shown at least once.
              memory
                     Caches  all  page  images in memory. This is the fastest method, but it requires very large
                     amounts of memory (about 3 MiB per page at 1024x768 resolution).
              compressed or z
                     Caches all page images in memory as well, but in compressed form. This  will  be  a  little
                     slower than memory mode, but on pages with uniform backgrounds, this will easily reduce the
                     required amount of RAM by a factor of 20.
              disk
                     Like memory, but uses a temporary file rather than memory for storage. This is the default.
              persistent
                     Uses  a  permanent  cache  file  for caching. This file will not be deleted when Impressive
                     quits and will be reused on subsequent invocations. The default name for the cache file  is
                     derived  like  the names for Info Scripts (see below for an explanation), but with a .cache
                     file name extension instead of .info. This method is a little bit slower  than  disk  mode,
                     but  the  time  span  until  the  overview  page  is  fully populated will be significantly
                     decreased if Impressive is ran again with the same input files and options.
              The mode name may be abbreviated at will, down to one  character.  Thus,  --cache  persistent,  -c
              persist and even -cp are all synonyms.

       -C <filename>[:<X>,<Y>] or --cursor <filename>[:<X>,<Y>]
              This  option  can  be  used  to  specify  an image that shall be used as a (software) mouse cursor
              instead of the normal (hardware) one. It can either be a  name  of  an  image  file  (typically  a
              transparent  .png)  or  one  of the special values "-" (dash) or "default", both of which select a
              built-in cursor image. On platforms that do not support a hardware  cursor,  this  default  cursor
              will also be used as a default if this option is not used.
              If  the  name  of an external file is specified, the position of the hotspot (the pixel inside the
              cursor where the actual mouse position is located) can be specified as well, for example: --cursor
              mycursor.png:2,4.

       --clock
              If this option is enabled, the current time will be shown instead of  the  elapsed  time  if  time
              display is activated (with the T key in the default control configuration). Compatible with the -M
              option.

       --control-help
              This  option  will output a short help screen of how the control configuration (keyboard and mouse
              bindings) work, along with a list of all recognized events and actions and a dump of  the  current
              bindings  (which  is  the  default  configuration  if  no other -e/--bind or -E/--controls options
              precede this option). After that, Impressive will exit; no presentation will be started.

       -d <time> or --duration <time>
              Specifies the expected run time of the presentation. The time parameter can be either a number  of
              seconds  or  a  human-readable  time  like  1:23  (1 minute and 23 seconds), 4:56h (4 hours and 56
              minutes), 3m45s (3 minutes and 45 seconds), 5m (5 minutes) or 1:23:45 (1 hour, 23 minutes  and  45
              seconds).
              If  an  expected duration is specified, Impressive will show a semi-transparent green progress bar
              at the bottom edge of the screen, indicating how much time has already passed. If the time is  up,
              the  bar  will  occupy the whole edge and fade to yellow (at 125% of the expected time) to red (at
              150% or more).

       -D <ms> or --mousedelay <ms>
              Sets the time (in milliseconds) the mouse cursor is shown if  it  is  not  moved.  There  are  two
              special  values:  0  (zero)  shows  the mouse cursor permanently, 1 (one) hides it completely. The
              default value is 3000 ms if Impressive is started in fullscreen mode, and 0 (i.e. don't  hide)  if
              started in windowed mode.

       --darkness <percentage>
              Specifies  how  much  the screen shall become darker when using highlight boxes or spotlight mode.
              The value is specified in percent, with 25 being the default.  A  value  of  zero  would  mean  no
              darkening  at  all  (the  screen  would  just be blurred slightly, and desaturated if the graphics
              hardware supports it), and a value of 100 would make everything but the highlighted parts  of  the
              screen black.

       -e <bindings> or --bind <bindings>
              Configures  keyboard  or  mouse  bindings.  For  the  syntax of the argument, refer to the Control
              Configuration section of the manual.

       -E <filename> or --controls <filename>
              Loads a configuration file for keyboard and mouse bindings. For the syntax of these  files,  refer
              to the Control Configuration section of the manual.

       --evtest
              If  this  option  is specified, Impressive will not start a normal presentation, but instead enter
              the so-called "Event Test Mode" after the display has been initialized. In this  mode,  Impressive
              will  simply  capture  all keyboard and mouse events and display the name of the last event on the
              screen. In addition, events will be logged to standard output. This mode  helps  with  determining
              the  event  names  for  each  key  when  creating  a custom control configuration (see the Control
              Configuration section).

       -f
              Sets the window/fullscreen mode Impressive shall start up  with.  This  option  can  be  specified
              multiple  times;  each  times  it  is  found,  the  next  of the three options is selected, in the
              following order: (1.)True fullscreen mode, including setting the video mode. This is  the  default
              mode.  (2.)Windowed  mode, where Impressive runs in a standard window. (3.)"Fake-fullscreen" mode,
              where fullscreen is emulated by using a window without border that fills the whole screen. Setting
              the display resolution is not possible in this mode. Each of these modes has a corresponding  long
              option that enables it directly (--fullscreen, --windowed and --fake-fullscreen).

       --fullscreen
              Starts  Impressive  in  fullscreen  mode  (the  default).  See the discussion of the -f option for
              details.

       --fake-fullscreen
              Starts Impressive in "fake fullscreen" mode. See the discussion of the -f option for details.

       -F <file> or --font <file>
              Impressive uses some kind of text OSD to overlay the current page number and title (if  available)
              on  the  overview  page. This option can be used to specify a TrueType font file (.ttf) to use for
              the OSD. If the path specified doesn't directly point to a useable font file, Impressive will  try
              to  search  the  system  font directories.  It assumes that all fonts are stored below /usr/share/
              fonts, /usr/local/share/fonts or /usr/X11R6/lib/X11/fonts/TTF for this purpose (the latter one  is
              useful  for Mac OS X systems specifically). If this option is not specified, any of DejaVuSans.ttf
              or Vera.ttf (the typical file name of Bitstream Vera Sans) will be used as a default.

       -g <width>x<height>[+<posX>+<posY>] or --geometry <width>x<height>[+<posX>+<posY>]
              Sets the screen size or resolution Impressive shall use (in pixels).  If xrandr is installed,  the
              default  screen  size  for  fullscreen  mode is the current screen resolution; on other platforms,
              Impressive uses the highest resolution available to the graphics system. If a standard  resolution
              cannot be determined, the default is 1024x768 pixels. This is also the default for windowed mode.
              Furthermore,  if the additional parameters posX and posY are present, they specify the position of
              the upper-left corner of the window (relative to the upper-left corner of the desktop), in pixels,
              for windowed and fake-fullscreen mode. The values are ignored in "true" fullscreen mode.

       -G <gamma>[:<blacklevel>] or --gamma <gamma>[:<blacklevel>]
              Sets up the startup gamma and (optional) black level  value.  The  black  level  is  the  original
              image's  intensity level (0...254) that is to be mapped to black in Impressive's output. Note that
              gamma and black level adjustments may be unavailable or constrained on some systems.

       -h or --help
              If this option is specified, Impressive writes a short command line help screen to standard output
              and does not start a presentation.

       -H or --half-screen
              This option makes Impressive show the overview page and OSD elements on  the  right  half  of  the
              screen  only.  The  overview  page  will  only  show  the left half of the slides as previews. The
              box-zoom boxes will also be shown on the left half.  Using  a  multi-monitor  setup  with  a  wide
              virtual  screen and specially crafted slides (e.g. those that can be generated with LaTeX's beamer
              class), this makes it possible to have presenter's notes on the second screen.
              Note that transitions and animations are still operating on the whole screen, making some of  them
              (like  PagePeel)  look  ugly.  Impressive also disables the overview zoom animation in half-screen
              mode; it can be re-enabled by explicitly setting it to another value with  a  later  command  line
              option (--zoomtime).
              Another  limitation  is  that the allocation of the screen halves (slides left, overview right) is
              fixed.

       -i <page> or --initialpage <page>
              Specifies the page number to start with. The default value is 1 (start with the  first  page).  If
              another  value  is  specified,  the page shown by Impressive right after initialization is not the
              first one of the PDF or image list. Additionally, pre-rendering (if enabled) will  also  start  at
              the specified page.

       -I <filename> or --script <filename>
              Overrides automatic derivation of the info script filename and specifies a script file directly.

       --invert
              This  option  makes  Impressive  invert  the  colors  of  each  page,  turning  black to white and
              vice-versa. Note that it is a full RGB inversion, so it will, for  example,  turn  dark  green  to
              light purple (and vice-versa) too.

       -k or --auto-progress
              This  option  makes Impressive show a progress bar, visualizing the timeout on pages that have one
              (either specified as a page property or using the --auto command-line option). Nothing is done  on
              pages that don't have a timeout.
              If the --duration or --page-progress bars are enabled too, the --auto-progress bar is shown on the
              top of the screen; otherwise, it's shown on the bottom.

       -l or --listtrans
              If  this  option  is  specified,  Impressive  writes a list of all available transition classes to
              standard output and does not start a presentation. Transitions that are  enabled  by  default  are
              marked with a star (*) left of the class name.

       -L <spec> or --layout <spec>
              Specifies the OSD layout. Read below for an explanation of this option.

       --maxzoom <factor>
              The  maximum zoom factor up to which Impressive shall attempt to render a high-resolution image of
              the page when zoomed in. This can be any real number larger than or equal to 1.0; the  default  is
              5.0.  A  setting  of 1.0 causes Impressive to never render a high-resolution image for zooming; in
              this case, the zoom and box-zoom modes will upscale the image, but not enhance any details.
              Note that regardless of this setting, Impressive always checks the graphics hardware  capabilities
              (in  particular,  the  maximum  supported  texture  size)  and  may  reduce the effective value of
              --maxzoom if the hardware supports less than what has been specified.

       --min-box-size <pixels>
              This option sets the minimum size of a highlight box, in pixels. Boxes  that  are  not  this  many
              pixels  wide and high are rejected in order to prevent accidental creation of highlight boxes. The
              default value for this is 30 pixels.

       -M or --minutes
              If this option is set, Impressive will show the on-screen timer (activated with the  T  key)  only
              with 1 minute resolution. By default, it will show a timer with 1 second resolution.

       --noblur
              By  default,  Impressive uses a fragment shader to blur and desaturate the image when in highlight
              box or spotlight mode. This is usually the faster and nicer-looking method; however, some very old
              hardware implementations can't deal with that shader and fall back to an  unusably  slow  software
              implementation.  Impressive  tries  to  detect scenarios where this would happen and automatically
              falls back to a different implementation.
              There  might  be  situations  where  this  mechanism  fails  and  Impressive  tries  to  use   the
              non-functional  shader  anyway.  In  these  cases,  the --noblur option can be used to enforce the
              fallback implementation.

       -N or --nocursor
              This option disables any display of a mouse cursor,  i.e.  neither  the  system  ("hardware")  not
              bitmap  ("software")  cursor  is shown at any time. It it equivalent to setting --mousedelay to 1.
              This is mainly useful for automated presentations, where no mouse interaction is needed.

       --noclicks
              If this option is enabled, switching to the previous or next page with the left  and  right  mouse
              buttons is deactivated. The keyboard shortcuts are unaffected from this.
              Note  that this option only works as intended when the default controls are used. If the -e/--bind
              or -E/--controls options have been used, --noclicks might not have the intended effect.

       --nologo
              This option disables the Impressive logo and version number display. Instead, the  loading  screen
              will be just black or, if background rendering is disabled, only the progress bar will be visible.

       --nooverview
              This  option  disables  the  overview  page. Overview thumbnails are not created, and the Tab that
              normally enters overview mode is ignored. (More precisely, the overview-enter action is ignored.)

       --noquit
              This option disables the keyboard shortcuts (Q and Esc) that could normally quit Impressive with a
              single keypress. If it is used, the only way to exit the program is the  key  combination  Alt+F4,
              and accidental quitting is no longer possible.
              Note  that  this  option only works properly if the default controls are used. If the -e/--bind or
              -E/--controls options have been used, --noquit might not have the intended effect.

       -o <directory> or --output <directory>
              Do not display the presentation, but render it into  a  series  of  PNG  image  files  inside  the
              specified directory. The images will be generated in the current resolution as specified by the -g
              option.  This  option is useful if the presentation is to be given on on a foreign PC with an old,
              broken or otherwise problematic MuPDF/Xpdf/GhostScript installation: By generating images  of  the
              PDF pages, is is made sure that no rendering bugs will happen on the target system.

       -O <mode> or --autooverview <mode>
              Enables  or  disables  automatic  derivation  of whether a page shall or shall not be shown on the
              overview page. This feature is based on the fact that some LaTeX  presentation  packages  tag  all
              pages  with  a  title  (that  can be read by Impressive with the help of pdftk), except those that
              contain multiple reveal steps.
              The following modes are available:
              off
                     Disables automatic overview mode. All pages will be shown on the overview page by  default.
                     This is also the default setting.
              first
                     All  pages  with a PDF title will be shown on the overview page. The purpose is to show the
                     initial state of multi-step slides on the overview page.
              last
                     All pages before a page with a PDF title will be shown on the overview page. The purpose is
                     to show the final state of multi-step slides on the overview page.
              Again, the mode may be abbreviated arbitrarily, down to one  character,  just  like  with  the  -c
              option above..

       --overtime <ms>
              Sets  the  duration  (in  milliseconds)  of  the  overview  page zoom-in/zoom-out effects, without
              affecting the zoom or box-zoom animation time. Default value: 250 ms.

       -p <start>-<end> or --pages <start>-<end>
              Using this option, the range of the page displayed can be narrowed  down.  The  presentation  will
              start  at  the  first  page  in the range. All pages outside of the range will not be shown on the
              overview page and will not be cached. However, they can be entered manually when  cycling  through
              the  presentation.  Due to the fact that these pages are uncached, preparation of the display will
              take considerably longer.

       -P <path> or --gspath <path>
              This option can be used to override the Xpdf / GhostScript path autodetection. The  full  path  to
              the executable of either GhostScript (gs or gs.exe) or Xpdf's pdftoppm utility must be specified.

       -q or --page-progress
              If  this option is enabled, Impressive will show a light-blue semi-transparent progress bar at the
              bottom edge of the screen that shows the position  inside  the  presentation,  i.e.  the  relation
              between the current page number and the total number of pages.
              If  the  -d/--duration  progress bar is enabled too, the --page-progress bar will be stacked above
              that.

       --progress-last <number>
              This option sets the page number at which the slide the --page-progress progress bar  should  end.
              This can be useful to ignore backup slides.
              This option does not have any effect if -q/--page-progress is not used.

       -Q or --autoquit
              If  this  option  is specified, Impressive quits automatically when trying to navigate to the page
              after the last page or the page before the first page.
              This option does not have any effect if --wrap is used.

       -r <n> or --rotate <n>
              Display all pages rotated by nx90 degrees clockwise. Try -r 1 or -r 3 if there are  problems  with
              PDFs generated by LaTeX on some Xpdf or GhostScript versions.

       -s or --scale (image input only)
              If  a  directory with image files is used as input, Impressive will scale down images that are too
              big for the screen. But by default, it will not scale up smaller images to fit the screen; it will
              leave a black border instead. This option overrides this setting and enables upscaling of  smaller
              images.

       -s or --supersample (PDF input only)
              This  switch  enables  antialiasing by 4x supersampling instead of the normal multisampling method
              used by Xpdf or GhostScript. While this usually degrades both visual quality and  performance,  it
              may be necessary for circumventing white strips or moire-like patterns in gradients.

       -S <pixels> or --fontsize <pixels>
              This option sets the size, in pixels, of the OSD font. The default value is 14.

       --spot-radius <pixels>
              This option sets the initial radius of the spotlight, in pixels. The default value is 64.

       --time-display
              This  option  enables  display  of the elapsed presentation time, as if the T key has been pressed
              immediately after startup. This implies time tracking mode (--tracking option).

       -t <trans1[,trans2...]> or --transition <trans1[,trans2...]>
              Using this switch, the set of transitions Impressive will randomly draw at  page  changes  can  be
              specified.  If  only one transition class is specified, this class will be used for all pages that
              do not have another transition explicitly assigned in their page properties. Multiple  transitions
              have  to  be  separated by commas; they will be used in random order. The -l option can be used to
              get a list of available transitions.

       -T <ms> or --transtime <ms>
              Sets the duration (in milliseconds) of page transitions. 0 (zero) disables transitions altogether.
              Default value: 1000 ms.

       --tracking
              This option enables time tracking mode. In this mode, a report of all  pages  visited  with  their
              display  duration,  enter  and  leave  times  will be written to standard output. This can be very
              useful when preparing presentations.

       -u <seconds> or --poll <seconds>
              If this option is specified, the source file or directory will be checked for  changes  regularly.
              If  a  change  in  the  input  PDF  file or any of the image files in the input image directory is
              detected, the page cache will be flushed and the current page as well as the info script  will  be
              reloaded.  The  current page's transition will be shown between the old and the new version of the
              page.
              The new PDF file must have at least as much pages as the old one; also, it should  have  the  same
              aspect ratio. If the input is a directory, image files must not have disappeared.

       -v or --verbose
              This option makes Impressive more verbose, i.e. it will print slightly more informational messages
              than usual.

       -V <pixels> or --overscan <pixels>
              PDF  files  often  contain tiny amounts of white borders around the edges which look bad in screen
              presentations. To eliminate this problem, Impressive  uses  "overscan":  PDF  files  will  not  be
              rendered  to  fit  the  screen  size  exactly,  but they will be rendered a bit larger so that the
              (possibly broken) borders can be cropped off. The amount of overscan, in screen pixels, can be set
              with this option. The default value is 3 pixels, which should remove borders in most presentations
              at most common screen resolutions without cropping the pages too much.

       -w or --wrap
              If this option is set, Impressive will "wrap" over to the first page after the last page. In other
              words, advancing to the next  page  at  the  end  of  the  presentation  will  restart  the  whole
              presentation.

       -W or --nowheel
              By  default,  it  is  possible  to  change  pages using the mouse wheel. This option disables this
              behavior, which can be useful to prevent spurious page changes if the mouse wheel is likely to  be
              moved by accident. In addition, it makes it possible to enter zoom mode with the mouse wheel.
              Note  that  this  option only works properly if the default controls are used. If the -e/--bind or
              -E/--controls options have been used, --nowheel might not have the intended effect.

       --windowed
              Starts Impressive in windowed mode. See the discussion of the -f option for details.

       -x or --fade
              This option enables a smooth fade-in effect at the start of the presentation and a fade-out effect
              just before Impressive quits.

       -X or --shuffle
              If this option is enabled, the input files will be shuffled into random order before starting  the
              presentation.  The  individual pages of PDF input files will stay in their original order, though,
              so this option is mainly useful for image presentations.

       -y or --auto-auto
              This option can be used together with --duration to have Impressive compute  a  page  timeout  (as
              with  the  --auto  option)  automatically. This results in a presentation that runs automatically,
              displaying each slide for the same time, so that  the  desired  total  duration  will  be  reached
              (almost) exactly. One exception is the runtime of videos, which is not taken into account.

       --zbox-edge <pixels>
              Sets  the  border  size (in pixels when unzoomed) of the box-zoom boxes' smooth edges. The default
              value is 1 pixel; it can be set to zero, in which case the box-zoom area will have a hard edge.

       -z <factor> or --zoom <factor>
              Sets the scaling factor that is used in zoom mode. It can be any real value above 1.0; the default
              value is 2.0. Note that it might not be possible  to  get  high-quality  zooming  for  large  zoom
              factors  due  to hardware restrictions. Furthermore, please be aware that after leaving zoom mode,
              the image quality of the normal page display may  be  slightly  degraded  until  another  page  is
              displayed if a zoom factor other than 2.0 is used.

       --zoomdarkness <percentage>
              Specifies  how much the non-selected parts of the screen shall become darker in box-zoom mode. The
              value is specified in percent, with 90 being the default. A value of zero would mean no  darkening
              at  all (parts outside of the zoom box would still be perfectly visible), and a value of 100 would
              make everything but the selected region black.

       -Z <ms> or --zoomtime <ms>
              Sets the duration (in milliseconds) of the  zoom,  box-zoom  and  overview  page  zoom-in/zoom-out
              effects, all at once. Default value: 250 ms.
              If  separate  animation  time  settings  for  overview zoom and zoom/box-zoom are desired, the -Z/
              --zoomtime option must be specified before the --overtime option.

       --cachefile <filename>
              Activates persistent cache mode and specifies the name of the cache file to use.

ARGUMENTS

       Following the options, the input file name(s) must be specified. Recognized file  types  are  PDF,  image
       files  (JPEG, PNG, TIFF, BMP, PGM/PPM) and video files (AVI, MOV/MP4, MKV/WebM, OGV, MPEG, M2TS, FLV). If
       the name of a directory is put on the command line, all recognized image files (no PDF  files!)  in  this
       directory will be played in alphanumeric order (case-insensitive).

       In  addition, Impressive can use a text file containing a list of files or directories to show: This text
       file must contain at most one file name per line; every character after a hash sign (#) is treated  as  a
       comment  and will be ignored. If such a comment is put on the same line as an image file name, it will be
       used as the page's title. List file names must be prefixed with an at sign (@) on the command line,  e.g.
       impressive @my_list_file.

       Impressive  will  also expand wild-card characters (* and ?) if this isn't already done by the shell, but
       apart from that, it will not reorder the arguments. Thus,  it  will  show  the  documents  in  the  order
       specified at the command line.

       If  video  files are specified on the command line, Impressive generates presentation pages for them just
       like it does for image files. If FFmpeg or MPlayer are installed, the page will be shown as a  screenshot
       of  the  first video frame. When entering such a page, the video will be played back if a suitable player
       (MPlayer, or omxplayer on Raspberry Pi) is installed.

LAYOUT OPTIONS

       The OSD layout option (-L/--layout) accepts a string with comma-separated key=value pairs. The  following
       keywords are recognized:
       alpha
              The  opacity  of  the  OSD  text, either as a floating-point value between 0 and 1 or a percentage
              between 2 and 100.
       margin
              The distance (in pixels) of the OSD text to the screen borders.
       time
              The position of the timer.
       title
              The position of the page title in overview mode.
       page
              The position of the page number in overview mode.
       status
              The position of the status line.
       The position specifications are composed by one character  that  indicates  whether  the  text  shall  be
       displayed  at  the  top  (T) or bottom (B) edge of the screen and one character that indicates whether it
       shall appear on the left (L), on the right (R) or centered (C).

       For example, the default OSD layout equals the following option string:
           -L margin=16,alpha=1,time=TR,title=BL,page=BR,status=TL

EXAMPLES

       The following examples illustrate some typical command lines. They assume that Impressive can be  run  by
       simply  typing "impressive" on the command line. Depending on how Impressive is installed, this has to be
       substituted with the actual way to run Impressive (e.g.  "python  ~/impressive/impressive_dev.py"  for  a
       fresh  SVN  checkout).  Furthermore,  the file "demo.pdf" is used as the document to show here; obviously
       this has to be replaced by the path to the actual PDF file too.

       In the simplest case, Impressive is run directly with the name  of  the  file  to  show  and  no  further
       parameters. This will start a full-screen presentation with all settings at their defaults:
           impressive demo.pdf

       To  just  quickly  check  a  slide  deck, it might make sense to run Impressive in a small window and not
       full-screen. This can be done with something like
           impressive -f -g 800x600 demo.pdf

       Impressive can also be used in digital signage scenarios, like displays in shop windows with a  permanent
       slideshow.  This  can  be  achieved  by  having Impressive advance to the next page automatically after a
       specified time (e.g. 10 seconds) and re-start the presentation from the start after the last slide:
           impressive -a 10 -w demo.pdf

USAGE

       On startup, Impressive will display a black screen with the program logo at the  center.  If  caching  is
       enabled,  but background rendering is disabled, all pages of the presentation will then be rendered once.
       A bar in the lower half of the screen displays the progress of this operation. Any  key  or  mouse  click
       (except  for  those  that  quit Impressive, typically Q and Esc) skips this process, with the effect that
       Impressive will render the remaining pages on demand. Please note that the  overview  page  will  not  be
       complete  until every page has been rendered at least once. In other words, if the precaching process was
       skipped, placeholders will be displayed for all pages that  have  not  been  rendered  yet.  By  default,
       Impressive  will build up the cache in the background while the presentation runs. Thus, the progress bar
       will not appear and the preparation will only take the amount of time required to render  the  first  two
       pages  of  the  presentation. After this initialization process, Impressive will switch to the first page
       directly and without any transition.

DEFAULT CONTROLS

       The keyboard and mouse controls used by Impressive are  configurable  (with  very  few  exceptions).  The
       default controls are as follows:

       Esc key
              Return  from  the  currently  active  special mode (zoom, box-zoom, overview, spotlight, highlight
              boxes); if no such special mode is active, quit Impressive altogether.

       Q key or Alt+F4
              Quit Impressive immediately.

       LMB (left mouse button), mouse wheel down, Page Down key, Cursor Down key, Cursor Right key or Spacebar
              Go to the next page (using a transition).

       RMB (right mouse button), mouse wheel up, Page Up key, Cursor Up key, Cursor Left key or Backspace key
              Go to the previous page (using a transition).

       Home key / End key
              Go directly to the first or last page of the presentation.

       Ctrl key (modifier)
              If one of the page navigation keys (Page Up/Down, Cursor keys, Space,  Backspace,  Home,  End)  is
              pressed while the Ctrl key is held down, the destination page will be entered immediately, without
              a transition.

       L key
              Return  to  the  last  (most  recently  displayed) page. This can be used to toggle back and forth
              between two pages.

       F key
              Toggle fullscreen mode.

       Tab key
              Zoom back to the overview page. While in overview mode, a page can be selected with the mouse  and
              activated  with  the  left  mouse  button.  The  right or middle mouse button or the Tab key leave
              overview mode without changing the current page.

       MMB (middle mouse button)
              In normal display mode, this acts like the Tab key: it zooms back to the  overview  page.  If  the
              page is zoomed in, it will return to normal mode.

       LMB over a PDF hyperlink
              Jump  to  the  page referenced by the hyperlink. Two types of hyperlinks are supported: Links that
              point to some other page of the same document, and  URL  hyperlinks  like  Web  links  and  e-mail
              addresses.  This  feature  is only available if pdftk is installed. Furthermore, xdg-open from the
              freedesktop.org Portland project is required  for  URL  links  to  work.   Please  note  that  the
              hyperlink feature will not work properly when pages are rotated.

       click&drag with LMB (left mouse button)
              Create  a  new highlight box. While at least one highlight box is defined on the current page, the
              page itself will be shown in a  darker,  blurry  and  (if  supported  by  the  graphics  hardware)
              desaturated  rendition.  Only  the  highlight boxes will be displayed in their original lightness,
              sharpness and color saturation.
              If a page with highlight boxes is left, the boxes will be saved and restored the  next  time  this
              page is shown again.

       click&drag with Ctrl+LMB (left mouse button)
              Draw  a  box  to  zoom  into.  This enters so-called "box-zoom" mode, where the selected region is
              zoomed into full view and anything else is displayed in much darker colors (but not  blurred  like
              in  highlight box mode). The page contents will be re-rendered in a higher resolution, if possible
              (limited to what has been configured with the --maxzoom  command-line  option,  and  the  graphics
              hardware's maximum supported texture size). To leave this mode again, use RMB, MMB or Esc.
              Note  that  box-zoom  mode is mutually exclusive with highlight boxes and the spotlight; if any of
              those is currently active, it's not possible to draw a zoom box.

       RMB (right mouse button) over a highlight box
              If the right mouse button is clicked while the mouse cursor is above a highlight box, the box will
              be removed. If the last box on a page is removed, the page will turn bright and sharp again.

       A key
              Toggle automatic slideshow mode.
              If an automatic presentation has been  started  with  the  -a/--auto  option,  it  is  temporarily
              disabled  until  this  key is pressed again. It is not automatically re-enabled after changing the
              page. If the -a/--auto has not been used, an automatic presentation with a timeout of  30  seconds
              is started when this key is pressed for the first time.
              Note  that  if  a  page has a timeout PageProp, the specified timeout is always in effect when the
              page is entered, even if the automatic slideshow is otherwise disabled.

       S key
              Save the info script associated with the current presentation. The main purpose  for  this  is  to
              permanently  save  highlight  boxes  or keyboard shortcuts, so they will be restored the next time
              this presentation is started.

       T key
              Activate or deactivate the time display at the upper-right corner of the screen. If the  timer  is
              activated while the very first page of the presentation is shown, it activates time tracking mode,
              just as if the command-line option --tracking had been specified.

       R key
              Reset the presentation timer.

       C key
              Removes ("clears") all highlight boxes from the current page.

       Return key or Enter key
              Toggle  spotlight  mode.  In this mode, the page is darkened in the same way as if highlight boxes
              are present, but instead of (or in addition to) the boxes, a circular "spotlight"  will  be  shown
              around the mouse cursor position, following every motion of the mouse cursor.

       + / - key, 9 / 0 key or mouse wheel in spotlight mode
              Adjust the spotlight radius.

       Ctrl+9 or Ctrl+0 keys
              Resets  the  spotlight  radius  to  the  default value, i.e. the value that has been set up by the
              radius page property, the --spot-radius command-line option or Impressive's built-in default.

       7 / 8 key
              Adjust the amount of darkening applied to the page in spotlight, highlight box or box-zoom mode.

       Ctrl+7 or Ctrl+8 keys
              Resets the amount of darkening in spotlight, highlight  box  and  box-zoom  mode  to  the  default
              values, i.e. the value that have been set up by the darkness and zoomdarkness page properties, the
              --darkness and --zoomdarkness command-line options or Impressive's built-in defaults.

       Z key
              Toggle  zoom mode. When this key is first pressed, the current page will zoom in. The page will be
              displayed at double size, but in its original resolution (i.e. it will be blurry). Impressive will
              re-render the page at the new resolution if the graphics hardware supports it. During  this  time,
              Impressive  will  not  accept  any input, so don't even think about clicking the mouse or pressing
              keys before the image gets crisp again.
              In zoom mode, all other functions will work as normal. Any operations that leave the current page,
              such as flipping the page or entering the overview screen, will leave zoom mode, too.

       [ / ] key
              Adjust the gamma value of the display (might not be supported on every hardware).

       { / } key
              Adjust the black level of the display (might not be supported on every hardware).

       \ key
              Revert gamma and black level back to normal.

       O key
              This will toggle the "visible on overview page" flag of the current page. The result will  not  be
              visible  immediately,  but  it  can  be  saved to the info script (using the S key) and will be in
              effect the next time the presentation is started.

       I key
              This will toggle the skip flag of the current page. A page marked as skipped will not be reachable
              with the normal forward/backward navigation keys.

       B / W key or . (dot) / , (comma) key
              Fade to black or white, respectively. This feature can be used if a whiteboard  or  blackboard  in
              front  of  the  projection  area  is to be used during the presentation. Using these two keys, the
              screen will fade into a solid color. On any keypress or mouse click, it will fade back to  normal.
              These keys are not available in overview mode.

       click&drag with MMB (middle mouse button) or RMB (right mouse button) in zoom mode
              Move the visible part of the page in zoom mode.

       mouse wheel up / down in zoom mode, U key
              Zoom  a  bit  in  or  out.  When  zoomed  out  fully,  zoom mode is left; note that in the default
              configuration, this means that when trying to zoom out even more using the wheel, the page is left
              instead. This is different if the -W/--nowheel option is used, where  page  navigation  using  the
              mouse  wheel  is  disabled,  and the wheel is always used for zooming. In this mode, the wheel can
              also be used to enter zoom mode in the first place.
              Note that changing the zoom level on the fly with the wheel does not make Impressive automatically
              re-render the page at a higher resolution to increase the level of detail. To do this, the  U  key
              needs to be pressed manually when the desired zoom level has been set up.

       Cursor keys in overview mode
              Navigate through pages.

       Alt+Tab keys
              If  Impressive  is in fullscreen mode, the window will be minimized so that other applications can
              be used.

       Any alphanumeric (A-z, 0-9) or function key (F1-F12) that is not bound to  a  specific  action  mentioned
       above  or  configured by the user (see below) can be used to assign shortcuts to pages that require quick
       access. If one of the keys is pressed together with Shift, the currently  displayed  page  is  associated
       with  this key. To recall the page later, it is sufficient to press the shortcut key again. Shortcuts can
       be stored permanently with the S key.

CONTROL CONFIGURATION

       As already mentioned in the previous chapter, the keyboard and mouse bindings of Impressive can be widely
       configured. The only exceptions are the Alt+F4 and Alt+Tab key combinations  that  will  always  quit  or
       minimize  Impressive,  respectively.  For  everything  else, there is a versatile configuration system in
       place; the controls described in the previous section are merely the defaults.

       Impressive's control system works by associating events with actions. An event is a key on the  keyboard,
       a  mouse  button  or  a mouse wheel movement. An action is something that is performed by Impressive as a
       result of an event, like going to the next page, switching to overview mode or quitting the program.  The
       association  of  an  event  to an an action is called a binding. Multiple events can be bound to the same
       action (like the page down and space keys in the default setting, both of which go  to  the  next  page);
       furthermore,  multiple  actions can be bound to the same event. In fact, bindings do not associate events
       with single actions at all, but with chains of actions. Only the first action in the chain  that  matches
       (i.e.  makes sense in) the current context will be executed if the event fires; all other actions will be
       ignored. If no action matches, no action will be performed and the event will be ignored.

       One example of such an action chain is the default binding for the  left  mouse  button,  which  draws  a
       highlight  box  if  the mouse cursor moved, or visits a hyperlink if the mouse cursor hovers over one, or
       goes to the next page if none of the other conditions are met.

       Both events and actions have mnemonic names that are used in the command-line options  and  configuration
       files  used  for  setting up bindings. Event and actions names are generally case-insensitive, though the
       canonical notation is lowercase.
       If an event or action specified on the command line or in a  configuration  file  is  not  recognized  by
       Impressive,  an  error  message  will be written to the console and the offending event or action will be
       ignored. Errors in control configuration are thus always non-fatal.

SUPPORTED EVENTS

       Keyboard events are generally named after the keys they refer to. Consequently, the events a to z  and  0
       to 9 mean the respective letter and number keys on the main keyboard, f1 to f12 are the function keys and
       kp0  to  kp9  are  the number keys on the numerical keypad. All of these are raw scancodes, which has two
       implications: First, the key names are not internationalized and refer to the US  keyboard  layout  (e.g.
       the Z key on a German or French keyboard will actually react to the event name y or w); second, modifiers
       will  be  ignored  as well (e.g. the numerical keypad will always generate the kpX scancodes, even if Num
       Lock is off).

       The mnemonic names for the other keyboard  events  are  as  follows  (in  alphabetic  order):  ampersand,
       asterisk,  at,  backquote, backslash, backspace, break, capslock, caret, clear, comma, down, end, escape,
       euro,  exclaim,  greater,  hash,  help,  home,  insert,  kp_divide,  kp_enter,   kp_equals,     kp_minus,
       kp_multiply, kp_plus, lalt, last, lctrl, left, leftbracket, leftparen, less, lmeta, lshift, lsuper, menu,
       minus,  mode,  numlock,  pagedown,  pageup, pause, period, plus, power, print, question, quote, quotedbl,
       ralt, rctrl, return, right, rightbracket, rightparen, rmeta, rshift, rsuper, scrollock, semicolon, slash,
       space, sysreq, tab, underscore, up. The events prefixed with kp_ refer to keys on the  numerical  keypad.
       Other than that, the names should be reasonably descriptive, so they will not be described futher at this
       point.  Also  note  that  not  all keyboards and platforms support the full range of keys defined in this
       list.

       Mouse event names are mapped as follows:

       lmb
              the left mouse button

       mmb
              the middle mouse button

       rmb
              the right mouse button

       wheelup
              scrolling the mouse wheel upwards

       wheeldown
              scrolling the mouse wheel downwards

       btnX (i.e. btn6, btn7, ...)
              additional mouse buttons, the mapping of which is  device-specific;  use  --evtest  to  see  which
              button is which

       The  event  names can be prefixed with the three modifiers ctrl+, alt+ and shift+ to make the event valid
       only if the specified set of modifiers is pressed as well. This works for both keyboard and mouse events.
       Multiple modifiers can be combined, but the order must match the one mentioned  in  this  paragraph.  For
       example, ctrl+shift+x is a valid event name, while shift+ctrl+x is not.

       A  simple  way  to determine the name associated with an event is using Impressive's "Event Test Mode" by
       invoking impressive --evtest. In this mode, the name of each incoming event  will  be  displayed  on  the
       screen  (and  logged  to  standard  output),  which  makes  it  possible  to  determine  event  names  by
       experimentation.

SUPPORTED ACTIONS

       The following list describes all actions supported by Impressive,  together  with  the  conditions  under
       which  they will match. Note that most actions will not match in overview mode and during video playback,
       unless mentioned otherwise in the description.

       auto-start
              (Re-)enable automatic presentation mode. If the current page has no timeout PageProp  and  no  -a/
              --auto  option  has  been  specified,  an  automatic presentation is started with a 30-second page
              interval.

       auto-stop
              Disable automatic presentation mode. If the current page has a timeout PageProp  or  an  -a/--auto
              option has been specified, the timeout for the current page is stopped.
              The  automatic  presentation  stays  disabled  after  changing pages, unless a timeout PageProp is
              specified for the target page, which will take precedence over the  otherwise  disabled  automatic
              presentation mode.

       auto-toggle
              Disables or (re-)enables automatic presentations, depending on the current state.

       box-add
              Draw  a  highlight  box  if  the mouse has been moved since the button has been pressed down. This
              action must only be bound to a mouse button event, otherwise it will not function properly.

       box-clear
              Removes all boxes from the current page.

       box-remove
              Removes the highlight box under the mouse cursor, if there is any.

       box-zoom
              Define a region to zoom into by drawing a rectangle. This action must only be  bound  to  a  mouse
              button event, otherwise it will not function properly.

       box-zoom-exit
              If in box-zoom (but not normal zoom) mode, leave box-zoom mode.

       fade-less, fade-more
              Decrease  or  increase the amount of darkening applied to the background in spotlight or highlight
              box mode.

       fade-reset
              Resets the background darkness in spotlight or highlight box mode to its default value.

       fade-to-black, fade-to-white
              Fades to a black or white screen. Once the screen is faded out, any event except  those  bound  to
              the quit action will just leave fade mode and not perform its assigned action.

       fullscreen
              Toggle fullscreen mode on platforms that support it.

       gamma-decrease, gamma-increase
              Decrease  or  increase  the  gamma level (i.e. roughly the brightness) of the display on platforms
              that support it.

       gamma-bl-decrease, gamma-bl-increase
              Decrease or increase the black level of the display on platforms that support it.

       gamma-reset
              Reset the gamma and black level settings to their defaults.

       goto-end, goto-end-notrans
              Go to the last page of the presentation, with or without a transition.

       goto-last, goto-last-notrans
              Go to the last (i.e. most recently) visited page, with or without a transition.

       goto-next, goto-next-notrans
              Go to the following page of the presentation, with or without a transition.

       goto-prev, goto-prev-notrans
              Go to the previous page of the presentation, with or without a transition.

       goto-start, goto-start-notrans
              Go to the first page of the presentation, with or without a transition.

       hyperlink, hyperlink-notrans
              Navigate to the hyperlink under the mouse cursor, if there is one. If the hyperlink is a reference
              to another page of the presentation, this page will be activated with or without a transition.  If
              the  hyperlink  refers  to  an  external  object  (e.g.  an URL), it will be opened externally, if
              supported by the system.

       overview-confirm
              When in overview mode, confirm the selection and leave overview mode, navigating to  the  selected
              page.

       overview-down, overview-up
              When in overview mode, select the page above or below the currently selected one in the grid.

       overview-enter
              When not in overview mode, zoom out of the current page, entering overview mode.

       overview-exit
              When  in  overview  mode,  leave  overview  mode, zooming back to the page that has been displayed
              before entering overview mode.

       overview-next, overview-prev
              When in overview mode, select the following or previous page.

       quit
              Quits Impressive immediately. This action is available in all modes.

       save
              Save or update the Info Script for the current presentation.

       spotlight-enter
              If spotlight mode is not active, enable spotlight mode.

       spotlight-exit
              If spotlight mode is active, deactivate spotlight mode.

       spotlight-grow, spotlight-shrink
              When in spotlight mode, increase or decrease the radius of the spotlight.

       spotlight-reset
              When in spotlight mode, reset the spotlight radius to the default value.

       time-reset
              Reset the presentation timer.

       time-toggle
              Toggle on-screen display of the current presentation time,  or  wall-clock  time  if  the  --clock
              option  is  used. If this is done at the start of the presentation, before the first page has been
              left, time tracking mode will be enabled, like the --tracking option would have done.

       toggle-overview
              This toggles the "page is visible on overview screen" flag for the current  page.  This  will  not
              have an immediate effect, but it can be saved to an Info Script.

       toggle-skip
              This  toggles  the  "skip  page when navigating with goto-prev and goto-next" flag for the current
              page.

       video-pause
              In video playback mode, this pauses or unpauses playback.

       video-seek-backward-10, video-seek-backward-1, video-seek-forward-1, video-seek-forward-10
              In video playback mode, seek forward or backward by 1 or 10 seconds.

       video-step
              In video playback mode, if playback is paused, advance one frame in the video.

       video-stop
              In video playback mode, stop playback and return to normal page display mode.

       zoom-enter
              If not in zoom mode, enter zoom mode with the zoom level configured with the -z/--zoom option.

       zoom-exit
              If in zoom or box-zoom mode, leave that mode.

       zoom-in, zoom-out
              Slightly increase or decrease the current zoom level. This does not change  the  page's  rendering
              resolution,  it  only  zooms  the  visible part of the screen in or out, centered around the mouse
              cursor's position. Zoom mode is left  automatically  if  the  zoom  level  goes  to  down  to  1x;
              conversely, zoom mode is entered when calling zoom-in while zoom mode is not active.

       zoom-pan
              If  in zoom mode, the visible area of the page can be moved around with the mouse while the key or
              mouse button of the associated event is held down.

       zoom-update
              If in zoom mode, re-render the current page in a resolution that best fits the current zoom level,
              up to the limits of the graphics hardware or the --maxzoom setting. This only  needs  to  be  done
              explicitly when zooming with the zoom-in action; zoom-enter and box-zoom do this automatically.

BINDING SYNTAX

       The arguments of the -e/--bind command-line option have the following basic syntax:
           <event> [,<event2>...] <operator> <action> [,<action2>...]
       In  other  words, it is a sequence of event names joined with commas, followed by an operator (see below)
       and a sequence of action names joined with commas. Multiple such binding statements can be combined  into
       one argument by joining them with a semicolon (;).

       The  used  operator  defines  in  which  way  the action list shall modify the bindings of the referenced
       events:

       = (equals sign), += (plus sign and equals sign)
              The specified actions will be added to the bindings of  the  specified  events.  In  other  words,
              event=action1,action2 does exactly the same as event=action1; event=action2.

       := (colon and equals sign)
              The specified actions will replace the bindings of the specified events.

       -= (minus sign and equals sign)
              The  specified  actions will be removed from the bindings of the specified events. For example, to
              make the Esc key in the default bindings not clear highlight boxes,  but  otherwise  preserve  its
              original functionality, escape -= box-clear can be used.

       Other than bindings, a statement can also contain one of the following special commands:

       clearall
              Clears all current bindings.

       defaults
              Discards all current bindings and (re-)establishes the default bindings.

       include <filename>
              Loads and executes a control configuration file with a specified name.

       The syntax for the configuration files used with the -E/--controls option or include statement is exactly
       the  same  as  for  the  ad-hoc  configuration  option, except that individual bindings can be written on
       individual lines instead of joining them together to a single long line  with  semicolons.  In  addition,
       everything following a hash sign (#) on a line will be ignored as a comment.

       One practical example for such a configuration file can be the following: The author of this program uses
       a  cheap  presentation remote control device that has four cursor keys, one "enter" key and a slider that
       switches between keyboard and mouse mode. Mouse mode works as expected, but what it does in keyboard mode
       is quite peculiar: the up and down keys act like Page-Up and Page-Down keys  on  a  keyboard,  the  right
       arrow  key sends the letter B to the computer, and the left key toggles between Esc and F5 each time it's
       pressed. The following configuration file allows basic navigation and access to overview mode  with  this
       device:

             clearall  # don't use the default bindings
             lmb = quit  # quit Impressive by clicking in mouse mode
             # everything else uses keyboard mode:
             return = overview-enter, overview-confirm  # toggle overview mode
             escape, f5 = overview-prev, goto-prev
             b = overview-next, goto-next
             pageup = overview-up, goto-prev
             pagedown = overview-down, goto-next

       To get a better idea of how the control configuration system works in practice, it's recommended to study
       the  output  of  impressive  --control-help  -  this  not only gives a concise overview of all events and
       actions, but also a full dump of Impressive's default bindings that can be used as a starting  point  for
       own customizations.

INFO SCRIPTS

       Impressive  offers  a powerful way to customize individual presentations using so-called info scripts. An
       info script is a text file having the same name and located in the same  directory  as  the  presentation
       file itself, except for the additional suffix .info. Thus, a presentation file called BrandNewProduct.pdf
       would  have a info script with the name BrandNewProduct.pdf.info. If multiple arguments were specified on
       the command line, the info script will be called just .info (a dot file, so to  speak).  If  a  directory
       name  was  specified as the only argument, either a file called DirectoryName.info or a file called .info
       inside the directory will be used, depending on whether a path separator was specified at the end of  the
       directory name or not - Impressive simply appends .info to whatever the input path name was.
       In any case, the default file name can be overridden by the -I command line option.

       Info  scripts  are  actually  Python  scripts with full access to Impressive's global data structures and
       functions. (It is possible, though heavily discouraged, to write real interactive applications using info
       scripts.) This has some good and bad side  effects.  The  bad  news  first:  The  info  scripts  must  be
       compatible  with  the  Python  version used by Impressive itself; it's best to write them in a way that's
       compatible with both Python  2.7  (with  the  __future__  imports  print_function,  unicode_literals  and
       division)  and  Python  3.x.  Furthermore, there's no built-in security; in other words: don't trust info
       scripts you received from somebody else. The good news, however, is that they can modify a broad range of
       settings concerning Impressive. This manual will only cover the most basic ones.

PAGE PROPERTIES

       The main part of an info script defines the properties  of  each  page.  At  the  moment,  the  following
       properties are defined:

       title
              Each  page can have a title that is displayed in the Impressive window's title bar. If there is no
              title explicitly specified in the info script, the title of the page will be  extracted  from  PDF
              metadata  if  pdftk  is  installed,  or the image file name will be used if the presentation is an
              image slideshow.

       transition
              With this property, the transition class to be used for rendering  the  transition  to  this  page
              (i.e.  between the previous page and this page) can be specified. For pages lacking this property,
              random transitions will be chosen. A list of available transition classes  can  be  obtained  with
              impressive -l.

       transtime
              This property overrides the global transition time parameter (-T at the command line). It contains
              the integer time (in milliseconds) the transition to this page shall take.

       overview
              This  property  holds a boolean value (0/False or 1/True) that specifies whether the page shall be
              included in the overview page. If this property isn't specified, it is assumed to be True.

       skip
              This boolean property can be set to 1/True if the page shall be skipped during the presentation.
              Pages with overview:True, skip:False will be accessible both by  cycling  through  the  pages  and
              using the overview page,
              pages  with overview:True, skip:True will be silently skipped in the normal page cycle, but remain
              accessible from the overview page,
              pages with overview:False, skip:False will appear in the normal cycle, but  not  on  the  overview
              page
              and pages with overview:False, skip:True will not be accessible at all.

       next
              This  property  can be set to the number of the page that shall be shown after this page. This can
              be used to skip a lot of pages without setting the skip property on each of those, or to create  a
              loop that can only be escaped by using the overview page or bookmarks.

       prev
              This  property  can be set to the number of the page that shall be shown when navigating from this
              page to the previous page (e.g. using the right mouse button or the Page-Up  key  in  the  default
              mappings).

       boxes
              This  property stores a list of highlight box coordinates. Normally, there is no need to edit this
              by hand, as Impressive handles this automatically if the S key is pressed.

       timeout
              If a timeout property is present and the page is shown, Impressive will  automatically  switch  to
              the  next  page  after  the  specified  number of milliseconds. Normally, the timeout will only be
              effective the first time the page is shown unless wrap mode is used  (command-line  option  -w  or
              --wrap).  This  restriction makes it possible to create self-running presentations with individual
              per-page timeouts.

       radius
              This property takes an integer value that, if defined, will be used to set a new spotlight  radius
              every time the page is entered. This overrides the current setting as defined by the --spot-radius
              command line option or run-time adjustments. Note that the value is not reset to the default value
              after the page has been left again.

       darkness
              This  property  takes an integer or floating-point percentage value that, if defined, will be used
              to set the background darkness in spotlight or highlight box mode each time the page  is  entered.
              This  overrides  the  current setting as defined by the --darkness command line option or run-time
              adjustments. Note that the value is not reset to the default value after the page  has  been  left
              again.

       zoomdarkness
              This  property  takes an integer or floating-point percentage value that, if defined, will be used
              to set the background darkness in box-zoom mode each time the page is entered. This overrides  the
              current setting as defined by the --zoomdarkness command line option or run-time adjustments. Note
              that the value is not reset to the default value after the page has been left again.

       comment
              This  property can hold a string with a single line of text that will be displayed on screen while
              the page is shown. Display of this text can not be disabled.

       sound
              Specifies the file name of a sound file to be played (via MPlayer) when the page is first entered.
              Once started, the sound will be played until its end is reached, another sound or video is played,
              or Impressive is exited.

       video
              Specifies the file name of a video file to be played when the page is  first  entered.  The  video
              will  be  displayed  full-screen.  Any  key or mouse click stops playback, except the cursor keys,
              which are used to seek in the video file, and space, which can be used to pause playback.
              Please not that this  function  is  still  somewhat  experimental.  It  uses  an  external  player
              application  (MPlayer, or omxplayer on Raspberry Pi) to perform the actual playback, and embeds it
              into Impressive's window.

       always
              If this property is present and set to 1 or True, the media file specified in the sound  or  video
              properties will be played every time the page is entered, not just the first time.

       progress
              If  this  property  is  set to zero, the presentation progress bars (which are set up with the -d/
              --duration, -q/--page-progress or -k/--auto-progress command line switches) will not be  shown  on
              this page. In practice, it might be useful to hide the bar(s) from the first page so that they are
              not visible during the introduction.

       reset
              If this property is set to 1 or True, the timer will be reset each time this page is left, just as
              if  the  R  has been pressed. If the special value 2 or FirstTimeOnly is used, the reset will only
              take place if the page was shown for the first time. Again, this is  particularly  useful  on  the
              first  page:  A combination of progress:False, reset:FirstTimeOnly makes it possible to set up the
              presentation long before it actually begins - the first page can be showed  as  long  as  desired,
              actual timing starts at the second page.

       rotate
              This  property  is  a per-page override of the global -r command line option: It specifies how the
              page shall be rotated, in 90-degree steps clockwise.

       OnEnter, OnLeave, OnEnterOnce, OnLeaveOnce
              These properties can contain a Python callable (i.e. a function reference  or  lambda  expression)
              that  is  executed when the page is entered or left. The ~Once variants will only be executed when
              the page is entered or left for the first time. The callable must not  take  any  arguments.  This
              feature can be used to associate arbitrary Python code with specific pages, for example to execute
              external programs.
              Warning: Lambda expressions cannot be properly processed by the Info Script save function (S key).
              If Impressive encounters lambda expressions when saving, it will remove them. In addition, it will
              not  overwrite  the  original info script, but generate an extra file that needs to be merged with
              the original script by hand.

       keys
              This property can be assigned a dictionary that maps alphanumerical keys to Python functions.  For
              example,  'keys':  { 'x': SomeFunction } will invoke SomeFunction() if the lowercase character 'x'
              is typed while the page is displayed. Regarding the functions, the same restrictions  as  for  the
              OnEnter/OnLeave  family  apply: the function must not take any parameters and lambda functions can
              not be saved. Also note that it is not possible to overwrite Impressive's pre-defined key bindings
              with this method.

       invert
              This property specifies whether the colors of that page shall be inverted  in  the  same  way  the
              --invert  command-line  switch does. It overrides the --invert setting on a per-page basis: If set
              to True, the page will always be inverted; if set to False, the page will never be  inverted  even
              if --invert has been specified on the command line.

       Note  that  in  Impressive  versions prior to 0.11.0, the transition and transtime properties defined the
       transition from the current page to the next, not from the previous page to the current one.

       The properties are stored together in a Python dictionary called PageProps. The syntax looks like in this
       example:

         PageProps = {
           1: {
                'title': "Title Page",
                'transition': PagePeel,
                'sound': "background_music.mp3"
              },
           2: {
                'title': "Another Page",
                'timeout': 5000
              }
         }

       The PageProps definition (and only the PageProps definition) will be rewritten by Impressive if the S key
       is pressed. User-defined PageProps entries will also be left untouched, except for some pretty-printing.

GLOBAL PRESENTATION PROPERTIES

       The name of the presentation is shown in the title bar of the Impressive window  (if  not  in  fullscreen
       mode).  By default, the file name or (if available) PDF metadata title will be used for this purpose, but
       the presentation title can also be explicitly set by overwriting the DocumentTitle variable:
           DocumentTitle = "My Presentation"

       Another useful variable, AvailableTransitions, contains a list of all transition classes that may be used
       for randomly assigning transitions  to  pages  lacking  the  transition  property.  Thus,  if  a  certain
       transition  is  undesired  (either because of personal dislike or because it shall be used exclusively on
       pages where it is manually assigned using PageProps), something like the following can be written:
           AvailableTransitions.remove(WipeBlobs)
       On the other side, it's possible to activate transitions that are not enabled by default:
           AvailableTransitions += [SlideUp, SlideDown]
       Alternatively, AvailableTransitions can be completely overwritten to have the same transition (or set  of
       transitions) assigned to all pages:
           AvailableTransitions = [Crossfade]

OPTION OVERRIDES

       Another  use of info scripts is overriding the default or command-line settings on a per-file basis. This
       can be done  by  simply  overwriting  one  of  the  variables  that  are  defined  at  the  beginning  of
       impressive.py.  Each of these variables corresponds either to a command-line setting, or to some constant
       related to  visual  appearance  or  performance.  So,  for  example,  to  force  fullscreen  mode  for  a
       presentation, write
           Fullscreen = True

WORKING DIRECTORIES

       The  working  directory  while executing the info scripts themselves is always the directory in which the
       info script is stored in.

       The base directory for external actions that originate from Page Properties or PDF hyperlinks  is  always
       the directory of the PDF or image file this page belongs to. In other words, if e.g. 'sound': "music.mp3"
       is  written  in  the  info  script for one page of presentation.pdf, the file music.mp3 is expected to be
       located in the same directory as presentation.pdf.

AUTHOR

       Impressive and its documentation has been written mainly by Martin J.  Fiedler  <martin.fiedler@gmx.net>,
       with small portions of the code written by external contributors. See the source code file for details.

REPORTING BUGS

       Report bugs to to <martin.fiedler@gmx.net>.

Martin J. Fiedler                                  2022-03-19                                      IMPRESSIVE(1)