Ubuntu Manpage: chafa - Character art facsimile generator

NAME

       chafa - Character art facsimile generator

SYNOPSIS

       chafa [OPTION...] [IMAGE...]

DESCRIPTION

       chafa is a utility that converts all kinds of images, including animated GIFs, into
       (potentially animated) ANSI/Unicode character output that can be displayed in a terminal.
       It supports alpha transparency and multiple color modes and color spaces, and combines a
       range of Unicode characters for optimal output.

       You can specify one or more input files, but the default behavior is slightly different
       with multiple files -- for instance, animations will not loop forever when there is more
       than one input file.

OPTIONS

--bg color
Background color of display (color name or hex). Partially transparent input will be
blended with this color. Color names are based on those provided with X.Org. Defaults
to black.

--clear
Clear screen before processing each file.

-c mode, --colors mode
Set output color mode; one of [none, 2, 8, 16, 240, 256, full]. Defaults to full
(24-bit). The 240-color mode is recommended over the 256-color one, since the lower 16
colors are unreliable and tend to differ between terminals. 16-color mode will use
aixterm extensions to produce 16 foreground and background colors. 2-color mode will
only emit the ANSI codes for reverse color and attribute reset, while "none" will emit
no ANSI color codes whatsoever.

In sixel mode, "full" will dynamically generate a 256-color palette for each image or
animation frame. The other modes refer to built-in palettes. "none" and "2" are
interchangeable and will use the specified foreground/background colors (see --fg and
--bg).

--color-extractor extractor
Method for extracting color from an area; one of [average, median]. Median normally
produces crisper output, while average may perform better on noisy images. Defaults to
average.

--color-space cs
Color space used for quantization; one of [rgb, din99d]. Defaults to rgb, which is
faster but less accurate.

--dither type
Type of dithering to apply during quantization. One of [none, ordered, diffusion].
"Bayer" is a synonym for "ordered", and "fs" (Floyd-Steinberg) is a synonym for
"diffusion".

--dither-grain widthxheight
Dimensions of grain used when dithering. Specified as width x height, where each can
be one of [1, 2, 4, 8] pixels. One character cell is by definition 8 pixels across in
both dimensions. Defaults to 4x4 in symbol mode and 1x1 in sixel mode.

--dither-intensity intensity
Intensity of dithering pattern. Ranges from 0.0 to infinity, with 1.0 considered
neutral. Lower values tend to reduce the amount of dithering done, while higher values
increase it. In practice, values higher than 10.0 are unlikely to produce useful
results.

-d, --duration seconds
Time to show each file, in seconds. Defaults to zero for still images and for
animations when multiple files are specified. If a single animation is specified,
defaults to infinite. Animations will always be played through at least once, even if
duration is e.g. zero.

--fg color
Foreground color of display (color name or hex). Together with the background color
specified by --bg, this specifies the terminal's palette in color modes 2 and none.
Color names are based on those provided with X.Org. Defaults to white.

--fg-only
Leave the background color untouched. This produces character-cell output using
foreground colors only, and will avoid resetting or inverting the colors.

--fill symbols
Specify character symbols to use for fill/gradients. Defaults to none. Usage is
similar to that of --symbols; see below.

--font-ratio width/height
Target font's width/height ratio. Can be specified as a real number or a fraction.
Defaults to 1/2.

-f, --format format
Set output format; one of [iterm, kitty, sixels, symbols]. The default is iterm, kitty
or sixels if the connected terminal supports one of these, falling back to symbols
("ANSI art") otherwise.

--glyph-file file
Load glyph information from file, which can be any font file supported by FreeType
(TTF, PCF, etc). The glyph outlines will replace any existing outlines, including
builtins. Useful in symbol mode for custom font support or for improving quality with
a specific font. Note that this only makes sense if the output terminal is using a
matching font. Can be specified multiple times.

-h, --help
Show a brief help text.

--invert
Invert video. For display with bright backgrounds in color modes 2 and none. Swaps
--fg and --bg.

-O num, --optimize num
Compress the output by using control sequences intelligently [0-9]. 0 disables, 9
enables every available optimization. Defaults to 5, except for when used with "-c
none", where it defaults to 0.

-p bool, --preprocess bool
Image preprocessing [on, off]. Defaults to on with 16 colors or lower, off otherwise.
This enhances colors and contrast prior to conversion, which can be useful in
low-color modes.

-s widthxheight, --size widthxheight
Set maximum output dimensions in columns and rows. By default this will be the size of
your terminal, or 80x25 if size detection fails.

--speed speed
Set the speed animations will play at. This can be either a unitless multiplier
(fractions are allowed), or a real number followed by "fps" to apply a specific
framerate.

--stretch
Stretch image to fit output dimensions; ignore aspect. Implies --zoom.

--symbols symbols
Specify character symbols to employ in final output. See below for full usage and a
list of symbol classes.

-t threshold, --threshold threshold
Threshold above which full transparency will be used [0.0 - 1.0]. Setting this to 0.0
will render a blank image, while a value of 1.0 will replace any transparency with the
background color (configurable with --bg).

--version
Show version, feature and copyright information.

--watch
Watch a single input file, redisplaying it whenever its contents change. Will run
until manually interrupted or, if --duration is set, until it expires.

-w num, --work num
How hard to work in terms of CPU and memory [1-9]. 1 is the cheapest, 9 is the most
accurate. Defaults to 5.

--zoom
Allow scaling up beyond one character per pixel.

SYMBOLS

       Accepted classes for --symbols are [all, none, space, solid, stipple, block, border,
       diagonal, dot, quad, half, hhalf, vhalf, inverted, braille, technical, geometric, ascii,
       legacy, sextant, wedge, wide, narrow]. Some symbols belong to multiple classes, e.g.
       diagonals are also borders.

       You can specify a list of classes separated by commas, or prefix them with + and - to add
       or remove symbols relative to the existing set. The ordering is significant.

       The default symbol set is block+border+space-wide-inverted for all modes except "none",
       which uses block+border+space-wide (including inverse symbols).

EXAMPLES

       chafa in.gif
           Show a potentially animated GIF image in the terminal. If this is an animation, it
           will run until the user generates an interrupt (typically ctrl-c). All parameters will
           be autodetected based on the current environment.

       chafa -c full -s 200 in.gif
           Like the above, but force truecolor output that is 200 characters wide and calculate
           the height preserving the aspect of the original image.

       chafa -c 16 --color-space din99d --symbols -dot in.jpg
           Generate 16-color output with perceptual color picking and avoid using dot symbols.

       chafa -c none --symbols block+border-solid in.png
           Generate uncolored output using block and border symbols, but avoid the solid block
           symbol.

AUTHOR

       Written by Hans Petter Jansson[2] <hpj@hpjansson.org>.

NOTES

        1. Chafa homepage
           https://hpjansson.org/chafa/

        2. Hans Petter Jansson
           https://hpjansson.org/