Provided by: picom_9-1_amd64 
NAME
picom - a compositor for X11
SYNOPSIS
picom [OPTIONS]
DESCRIPTION
picom is a compositor based on Dana Jansens' version of xcompmgr (which itself was written by Keith
Packard). It includes some improvements over the original xcompmgr, like window frame opacity and
inactive window transparency.
OPTIONS
-h, --help
Get the usage text embedded in program code, which may be more up-to-date than this man page.
-r, --shadow-radius=RADIUS
The blur radius for shadows, in pixels. (defaults to 12)
-o, --shadow-opacity=OPACITY
The opacity of shadows. (0.0 - 1.0, defaults to 0.75)
-l, --shadow-offset-x=OFFSET
The left offset for shadows, in pixels. (defaults to -15)
-t, --shadow-offset-y=OFFSET
The top offset for shadows, in pixels. (defaults to -15)
-I, --fade-in-step=OPACITY_STEP
Opacity change between steps while fading in. (0.01 - 1.0, defaults to 0.028)
-O, --fade-out-step=OPACITY_STEP
Opacity change between steps while fading out. (0.01 - 1.0, defaults to 0.03)
-D, --fade-delta=MILLISECONDS
The time between steps in fade step, in milliseconds. (> 0, defaults to 10)
-c, --shadow
Enabled client-side shadows on windows. Note desktop windows (windows with
_NET_WM_WINDOW_TYPE_DESKTOP) never get shadow, unless explicitly requested using the wintypes option.
-f, --fading
Fade windows in/out when opening/closing and when opacity changes, unless --no-fading-openclose is
used.
-F
Equals to -f. Deprecated.
-i, --inactive-opacity=OPACITY
Opacity of inactive windows. (0.1 - 1.0, defaults to 1.0)
-e, --frame-opacity=OPACITY
Opacity of window titlebars and borders. (0.1 - 1.0, disabled by default)
-b, --daemon
Daemonize process. Fork to background after initialization. This option can only be set from the
command line, setting this in the configuration file will have no effect.
--log-level
Set the log level. Possible values are "TRACE", "DEBUG", "INFO", "WARN", "ERROR", in increasing level
of importance. Case doesn’t matter. If using the "TRACE" log level, it’s better to log into a file
using --log-file, since it can generate a huge stream of logs.
--log-file
Set the log file. If --log-file is never specified, logs will be written to stderr. Otherwise, logs
will to written to the given file, though some of the early logs might still be written to the
stderr. When setting this option from the config file, it is recommended to use an absolute path.
--experimental-backends
Use the new, reimplemented version of the backends. The new backends are HIGHLY UNSTABLE at this
point, you have been warned. This option is not available in the config file.
--show-all-xerrors
Show all X errors (for debugging).
--config PATH
Look for configuration file at the path. See CONFIGURATION FILES section below for where picom looks
for a configuration file by default. Use /dev/null to avoid loading configuration file.
--write-pid-path PATH
Write process ID to a file. it is recommended to use an absolute path.
--shadow-color STRING
Color of shadow, as a hex string (#000000)
--shadow-red VALUE
Red color value of shadow (0.0 - 1.0, defaults to 0).
--shadow-green VALUE
Green color value of shadow (0.0 - 1.0, defaults to 0).
--shadow-blue VALUE
Blue color value of shadow (0.0 - 1.0, defaults to 0).
--inactive-opacity-override
Let inactive opacity set by -i override the _NET_WM_WINDOW_OPACITY values of windows.
--active-opacity OPACITY
Default opacity for active windows. (0.0 - 1.0, defaults to 1.0)
--inactive-dim VALUE
Dim inactive windows. (0.0 - 1.0, defaults to 0.0)
--corner-radius VALUE
Sets the radius of rounded window corners. When > 0, the compositor will round the corners of
windows. Does not interact well with --transparent-clipping. (defaults to 0).
--rounded-corners-exclude CONDITION
Exclude conditions for rounded corners.
--mark-wmwin-focused
Try to detect WM windows (a non-override-redirect window with no child that has WM_STATE) and mark
them as active.
--mark-ovredir-focused
Mark override-redirect windows that doesn’t have a child window with WM_STATE focused.
--no-fading-openclose
Do not fade on window open/close.
--no-fading-destroyed-argb
Do not fade destroyed ARGB windows with WM frame. Workaround of bugs in Openbox, Fluxbox, etc.
--shadow-ignore-shaped
Do not paint shadows on shaped windows. Note shaped windows here means windows setting its shape
through X Shape extension. Those using ARGB background is beyond our control. Deprecated, use
--shadow-exclude 'bounding_shaped' or --shadow-exclude 'bounding_shaped && !rounded_corners' instead.
--detect-rounded-corners
Try to detect windows with rounded corners and don’t consider them shaped windows. The accuracy is
not very high, unfortunately.
--detect-client-opacity
Detect _NET_WM_WINDOW_OPACITY on client windows, useful for window managers not passing
_NET_WM_WINDOW_OPACITY of client windows to frame windows.
--vsync, --no-vsync
Enable/disable VSync.
--use-ewmh-active-win
Use EWMH _NET_ACTIVE_WINDOW to determine currently focused window, rather than listening to
FocusIn/FocusOut event. Might have more accuracy, provided that the WM supports it.
--unredir-if-possible
Unredirect all windows if a full-screen opaque window is detected, to maximize performance for
full-screen windows. Known to cause flickering when redirecting/unredirecting windows.
--unredir-if-possible-delay MILLISECONDS
Delay before unredirecting the window, in milliseconds. Defaults to 0.
--unredir-if-possible-exclude CONDITION
Conditions of windows that shouldn’t be considered full-screen for unredirecting screen.
--shadow-exclude CONDITION
Specify a list of conditions of windows that should have no shadow.
--clip-shadow-above CONDITION
Specify a list of conditions of windows that should have no shadow painted over, such as a dock
window.
--fade-exclude CONDITION
Specify a list of conditions of windows that should not be faded.
--focus-exclude CONDITION
Specify a list of conditions of windows that should always be considered focused.
--inactive-dim-fixed
Use fixed inactive dim value, instead of adjusting according to window opacity.
--detect-transient
Use WM_TRANSIENT_FOR to group windows, and consider windows in the same group focused at the same
time.
--detect-client-leader
Use WM_CLIENT_LEADER to group windows, and consider windows in the same group focused at the same
time. This usually means windows from the same application will be considered focused or unfocused at
the same time.WM_TRANSIENT_FOR has higher priority if --detect-transient is enabled, too.
--blur-method, --blur-size, --blur-deviation, --blur-strength
Parameters for background blurring, see the BLUR section for more information.
--blur-background
Blur background of semi-transparent / ARGB windows. Bad in performance, with driver-dependent
behavior. The name of the switch may change without prior notifications.
--blur-background-frame
Blur background of windows when the window frame is not opaque. Implies --blur-background. Bad in
performance, with driver-dependent behavior. The name may change.
--blur-background-fixed
Use fixed blur strength rather than adjusting according to window opacity.
--blur-kern MATRIX
Specify the blur convolution kernel, with the following format:
WIDTH,HEIGHT,ELE1,ELE2,ELE3,ELE4,ELE5...
In other words, the matrix is formatted as a list of comma separated numbers. The first two numbers
must be integers, which specify the width and height of the matrix. They must be odd numbers. Then,
the following width * height - 1 numbers specifies the numbers in the matrix, row by row, excluding
the center element.
The elements are finite floating point numbers. The decimal pointer has to be . (a period),
scientific notation is not supported.
The element in the center will either be 1.0 or varying based on opacity, depending on whether you
have --blur-background-fixed. Yet the automatic adjustment of blur factor may not work well with a
custom blur kernel.
A 7x7 Gaussian blur kernel (sigma = 0.84089642) looks like:
--blur-kern '7,7,0.000003,0.000102,0.000849,0.001723,0.000849,0.000102,0.000003,0.000102,0.003494,0.029143,0.059106,0.029143,0.003494,0.000102,0.000849,0.029143,0.243117,0.493069,0.243117,0.029143,0.000849,0.001723,0.059106,0.493069,0.493069,0.059106,0.001723,0.000849,0.029143,0.243117,0.493069,0.243117,0.029143,0.000849,0.000102,0.003494,0.029143,0.059106,0.029143,0.003494,0.000102,0.000003,0.000102,0.000849,0.001723,0.000849,0.000102,0.000003'
May also be one of the predefined kernels: 3x3box (default), 5x5box, 7x7box, 3x3gaussian,
5x5gaussian, 7x7gaussian, 9x9gaussian, 11x11gaussian. All Gaussian kernels are generated with sigma =
0.84089642 . If you find yourself needing to generate custom blur kernels, you might want to try the
new blur configuration supported by the experimental backends (See BLUR and --experimental-backends).
--blur-background-exclude CONDITION
Exclude conditions for background blur.
--resize-damage INTEGER
Resize damaged region by a specific number of pixels. A positive value enlarges it while a negative
one shrinks it. If the value is positive, those additional pixels will not be actually painted to
screen, only used in blur calculation, and such. (Due to technical limitations, with --use-damage,
those pixels will still be incorrectly painted to screen.) Primarily used to fix the line corruption
issues of blur, in which case you should use the blur radius value here (e.g. with a 3x3 kernel, you
should use --resize-damage 1, with a 5x5 one you use --resize-damage 2, and so on). May or may not
work with --glx-no-stencil. Shrinking doesn’t function correctly.
--invert-color-include CONDITION
Specify a list of conditions of windows that should be painted with inverted color. Resource-hogging,
and is not well tested.
--opacity-rule OPACITY:'CONDITION'
Specify a list of opacity rules, in the format PERCENT:PATTERN, like 50:name *= "Firefox".
picom-trans is recommended over this. Note we don’t make any guarantee about possible conflicts with
other programs that set _NET_WM_WINDOW_OPACITY on frame or client windows.
--shadow-exclude-reg GEOMETRY
Specify a X geometry that describes the region in which shadow should not be painted in, such as a
dock window region. Use --shadow-exclude-reg x10+0-0, for example, if the 10 pixels on the bottom of
the screen should not have shadows painted on.
--xinerama-shadow-crop
Crop shadow of a window fully on a particular Xinerama screen to the screen.
--backend BACKEND
Specify the backend to use: xrender, glx, or xr_glx_hybrid. xrender is the default one.
• xrender backend performs all rendering operations with X Render extension. It is what xcompmgr
uses, and is generally a safe fallback when you encounter rendering artifacts or instability.
• glx (OpenGL) backend performs all rendering operations with OpenGL. It is more friendly to some
VSync methods, and has significantly superior performance on color inversion
(--invert-color-include) or blur (--blur-background). It requires proper OpenGL 2.0 support from
your driver and hardware. You may wish to look at the GLX performance optimization options below.
--xrender-sync-fence might be needed on some systems to avoid delay in changes of screen
contents.
• xr_glx_hybrid backend renders the updated screen contents with X Render and presents it on the
screen with GLX. It attempts to address the rendering issues some users encountered with GLX
backend and enables the better VSync of GLX backends. --vsync-use-glfinish might fix some
rendering issues with this backend.
--glx-no-stencil
GLX backend: Avoid using stencil buffer, useful if you don’t have a stencil buffer. Might cause
incorrect opacity when rendering transparent content (but never practically happened) and may not
work with --blur-background. My tests show a 15% performance boost. Recommended.
--glx-no-rebind-pixmap
GLX backend: Avoid rebinding pixmap on window damage. Probably could improve performance on rapid
window content changes, but is known to break things on some drivers (LLVMpipe, xf86-video-intel,
etc.). Recommended if it works.
--no-use-damage
Disable the use of damage information. This cause the whole screen to be redrawn every time, instead
of the part of the screen has actually changed. Potentially degrades the performance, but might fix
some artifacts.
--xrender-sync-fence
Use X Sync fence to sync clients' draw calls, to make sure all draw calls are finished before picom
starts drawing. Needed on nvidia-drivers with GLX backend for some users.
--glx-fshader-win SHADER
GLX backend: Use specified GLSL fragment shader for rendering window contents. See
compton-default-fshader-win.glsl and compton-fake-transparency-fshader-win.glsl in the source tree
for examples.
--force-win-blend
Force all windows to be painted with blending. Useful if you have a --glx-fshader-win that could turn
opaque pixels transparent.
--dbus
Enable remote control via D-Bus. See the D-BUS API section below for more details.
--benchmark CYCLES
Benchmark mode. Repeatedly paint until reaching the specified cycles.
--benchmark-wid WINDOW_ID
Specify window ID to repaint in benchmark mode. If omitted or is 0, the whole screen is repainted.
--no-ewmh-fullscreen
Do not use EWMH to detect fullscreen windows. Reverts to checking if a window is fullscreen based
only on its size and coordinates.
--max-brightness
Dimming bright windows so their brightness doesn’t exceed this set value. Brightness of a window is
estimated by averaging all pixels in the window, so this could comes with a performance hit. Setting
this to 1.0 disables this behaviour. Requires --use-damage to be disabled. (default: 1.0)
--transparent-clipping
Make transparent windows clip other windows like non-transparent windows do, instead of blending on
top of them.
FORMAT OF CONDITIONS
Some options accept a condition string to match certain windows. A condition string is formed by one or
more conditions, joined by logical operators.
A condition with "exists" operator looks like this:
<NEGATION> <TARGET> <CLIENT/FRAME> [<INDEX>] : <FORMAT> <TYPE>
With equals operator it looks like:
<NEGATION> <TARGET> <CLIENT/FRAME> [<INDEX>] : <FORMAT> <TYPE> <NEGATION> <OP QUALIFIER> <MATCH TYPE> = <PATTERN>
With greater-than/less-than operators it looks like:
<NEGATION> <TARGET> <CLIENT/FRAME> [<INDEX>] : <FORMAT> <TYPE> <NEGATION> <OPERATOR> <PATTERN>
NEGATION (optional) is one or more exclamation marks;
TARGET is either a predefined target name, or the name of a window property to match. Supported
predefined targets are id, x, y, x2 (x + widthb), y2 (like x2), width, height, widthb (width + 2 *
border_width), heightb (like widthb), border_width, fullscreen, override_redirect, argb (whether the
window has an ARGB visual), focused, wmwin (whether the window looks like a WM window, i.e. has no child
window with WM_STATE and is not override-redirected), bounding_shaped, rounded_corners (requires
--detect-rounded-corners), client (ID of client window), window_type (window type in string), leader (ID
of window leader), name, class_g (= WM_CLASS[1]), class_i (= WM_CLASS[0]), and role.
CLIENT/FRAME is a single @ if the window attribute should be be looked up on client window, nothing if on
frame window;
INDEX (optional) is the index number of the property to look up. For example, [2] means look at the third
value in the property. If not specified, the first value (index [0]) is used implicitly. Use the special
value [*] to perform matching against all available property values using logical OR. Do not specify it
for predefined targets.
FORMAT (optional) specifies the format of the property, 8, 16, or 32. On absence we use format X reports.
Do not specify it for predefined or string targets.
TYPE is a single character representing the type of the property to match for: c for CARDINAL, a for
ATOM, w for WINDOW, d for DRAWABLE, s for STRING (and any other string types, such as UTF8_STRING). Do
not specify it for predefined targets.
OP QUALIFIER (optional), applicable only for equals operator, could be ? (ignore-case).
MATCH TYPE (optional), applicable only for equals operator, could be nothing (exact match), * (match
anywhere), ^ (match from start), % (wildcard), or ~ (PCRE regular expression).
OPERATOR is one of = (equals), <, >, <=, =>, or nothing (exists). Exists operator checks whether a
property exists on a window (but for predefined targets, exists means != 0 then).
PATTERN is either an integer or a string enclosed by single or double quotes. Python-3-style escape
sequences and raw string are supported in the string format.
Supported logical operators are && (and) and || (or). && has higher precedence than ||, left-to-right
associativity. Use parentheses to change precedence.
Examples:
# If the window is focused
focused
focused = 1
# If the window is not override-redirected
!override_redirect
override_redirect = false
override_redirect != true
override_redirect != 1
# If the window is a menu
window_type *= "menu"
_NET_WM_WINDOW_TYPE@:a *= "MENU"
# If the window is marked hidden: _NET_WM_STATE contains _NET_WM_STATE_HIDDEN
_NET_WM_STATE@[*]:a = "_NET_WM_STATE_HIDDEN"
# If the window is marked sticky: _NET_WM_STATE contains an atom that contains
# "sticky", ignore case
_NET_WM_STATE@[*]:a *?= "sticky"
# If the window name contains "Firefox", ignore case
name *?= "Firefox"
_NET_WM_NAME@:s *?= "Firefox"
# If the window name ends with "Firefox"
name %= "*Firefox"
name ~= "Firefox$"
# If the window has a property _COMPTON_SHADOW with value 0, type CARDINAL,
# format 32, value 0, on its frame window
_COMPTON_SHADOW:32c = 0
# If the third value of _NET_FRAME_EXTENTS is less than 20, or there's no
# _NET_FRAME_EXTENTS property on client window
_NET_FRAME_EXTENTS@[2]:32c < 20 || !_NET_FRAME_EXTENTS@:32c
# The pattern here will be parsed as "dd4"
name = "\x64\x64\o64"
# The pattern here will be parsed as "\x64\x64\x64"
name = r"\x64\x64\o64"
LEGACY FORMAT OF CONDITIONS
This is the old condition format we once used. Support of this format might be removed in the future.
condition = TARGET:TYPE[FLAGS]:PATTERN
TARGET is one of "n" (window name), "i" (window class instance), "g" (window general class), and "r"
(window role).
TYPE is one of "e" (exact match), "a" (match anywhere), "s" (match from start), "w" (wildcard), and "p"
(PCRE regular expressions, if compiled with the support).
FLAGS could be a series of flags. Currently the only defined flag is "i" (ignore case).
PATTERN is the actual pattern string.
CONFIGURATION FILES
picom could read from a configuration file if libconfig support is compiled in. If --config is not used,
picom will seek for a configuration file in $XDG_CONFIG_HOME/picom.conf (~/.config/picom.conf, usually),
then $XDG_CONFIG_HOME/picom/picom.conf, then $XDG_CONFIG_DIRS/picom.conf (often /etc/xdg/picom.conf),
then $XDG_CONFIG_DIRS/picom/picom.conf.
picom uses general libconfig configuration file format. A sample configuration file is available as
picom.sample.conf in the source tree. Most of commandline switches can be used as options in
configuration file as well. For example, --vsync option documented above can be set in the configuration
file using `vsync = `. Command line options will always overwrite the settings in the configuration file.
Window-type-specific settings are exposed only in configuration file and has the following format:
wintypes:
{
WINDOW_TYPE = { fade = BOOL; shadow = BOOL; opacity = FLOAT; focus = BOOL; blur-background = BOOL; full-shadow = BOOL; clip-shadow-above = BOOL; redir-ignore = BOOL; };
};
WINDOW_TYPE is one of the 15 window types defined in EWMH standard: "unknown", "desktop", "dock",
"toolbar", "menu", "utility", "splash", "dialog", "normal", "dropdown_menu", "popup_menu", "tooltip",
"notification", "combo", and "dnd".
Following per window-type options are available:
fade, shadow
Controls window-type-specific shadow and fade settings.
opacity
Controls default opacity of the window type.
focus
Controls whether the window of this type is to be always considered focused. (By default, all
window types except "normal" and "dialog" has this on.)
blur-background
Controls wether the window of this type will have its transparent background blurred.
full-shadow
Controls whether shadow is drawn under the parts of the window that you normally won’t be able to
see. Useful when the window has parts of it transparent, and you want shadows in those areas.
clip-shadow-above
Controls wether shadows that would have been drawn above the window should be clipped. Useful for
dock windows that should have no shadow painted on top.
redir-ignore
Controls whether this type of windows should cause screen to become redirected again after been
unredirected. If you have --unredir-if-possible set, and doesn’t want certain window to cause
unnecessary screen redirection, you can set this to true.
BLUR
You can configure how the window background is blurred using a blur section in your configuration file.
Here is an example:
blur:
{
method = "gaussian";
size = 10;
deviation = 5.0;
};
Available options of the blur section are:
method
A string. Controls the blur method. Corresponds to the --blur-method command line option.
Available choices are: none to disable blurring; gaussian for gaussian blur; box for box blur;
kernel for convolution blur with a custom kernel; dual_kawase for dual-filter kawase blur. Note:
gaussian, box and dual_kawase blur methods are only supported by the experimental backends.
(default: none)
size
An integer. The size of the blur kernel, required by gaussian and box blur methods. For the
kernel method, the size is included in the kernel. Corresponds to the --blur-size command line
option (default: 3).
deviation
A floating point number. The standard deviation for the gaussian blur method. Corresponds to the
--blur-deviation command line option (default: 0.84089642).
strength
An integer in the range 0-20. The strength of the dual_kawase blur method. Corresponds to the
--blur-strength command line option. If set to zero, the value requested by --blur-size is
approximated (default: 5).
kernel
A string. The kernel to use for the kernel blur method, specified in the same format as the
--blur-kerns option. Corresponds to the --blur-kerns command line option.
SIGNALS
• picom reinitializes itself upon receiving SIGUSR1.
D-BUS API
It’s possible to control picom via D-Bus messages, by running picom with --dbus and send messages to
com.github.chjj.compton.<DISPLAY>. <DISPLAY> is the display used by picom, with all non-alphanumeric
characters transformed to underscores. For DISPLAY=:0.0 you should use com.github.chjj.compton._0_0, for
example.
The D-Bus methods and signals are not yet stable, thus undocumented right now.
EXAMPLES
• Disable configuration file parsing:
$ picom --config /dev/null
• Run picom with client-side shadow and fading:
$ picom -cf
• Same thing as above, plus making inactive windows 80% transparent, making frame 80% transparent,
don’t fade on window open/close, and fork to background:
$ picom -bcf -i 0.8 -e 0.8 --no-fading-openclose
• Draw white shadows:
$ picom -c --shadow-red 1 --shadow-green 1 --shadow-blue 1
• Avoid drawing shadows on wbar window:
$ picom -c --shadow-exclude 'class_g = "wbar"'
• Enable VSync with GLX backend:
$ picom --backend glx --vsync
BUGS
Please submit bug reports to https://github.com/yshui/picom.
Out dated information in this man page is considered a bug.
RESOURCES
Homepage: https://github.com/yshui/picom
SEE ALSO
xcompmgr(1), picom-trans(1)
picom v9 02/06/2022 PICOM(1)