icat

Display images in the terminal

The icat kitten can be used to display arbitrary images in the kitty terminal. Using it is as simple as:

kitty +kitten icat image.jpeg

It supports all image types supported by ImageMagick. It even works over SSH. For details, see the kitty graphics protocol.

You might want to create an alias in your shell’s configuration files:

alias icat="kitty +kitten icat"

Then you can simply use icat image.png to view images.

Note

ImageMagick must be installed for icat kitten to work.

Note

kitty’s image display protocol may not work when used within a terminal multiplexer such as screen or tmux, depending on whether the multiplexer has added support for it or not.

The icat kitten has various command line arguments to allow it to be used from inside other programs to display images. In particular, --place, --detect-support, --silent and --print-window-size.

If you are trying to integrate icat into a complex program like a file manager or editor, there are a few things to keep in mind. icat works by communicating over the TTY device, it both writes to and reads from the TTY. So it is imperative that while it is running the host program does not do any TTY I/O. Any key presses or other input from the user on the TTY device will be discarded. At a minimum, you should use the --silent and --transfer-mode command line arguments. To be really robust you should consider writing proper support for the kitty graphics protocol in the program instead. Nowadays there are many libraries that have support for it.

Source code for icat

The source code for this kitten is available on GitHub.

Command Line Interface

kitty +kitten icat [options] image-file-or-url-or-directory ...

A cat like utility to display images in the terminal. You can specify multiple image files and/or directories. Directories are scanned recursively for image files. If STDIN is not a terminal, image data will be read from it as well. You can also specify HTTP(S) or FTP URLs which will be automatically downloaded and displayed.

Options

--align <ALIGN>

Horizontal alignment for the displayed image. Default: center Choices: center, left, right

--place <PLACE>

Choose where on the screen to display the image. The image will be scaled to fit into the specified rectangle. The syntax for specifying rectangles is <width>x<height>@<left>x<top>. All measurements are in cells (i.e. cursor positions) with the origin (0, 0) at the top-left corner of the screen.

--scale-up

When used in combination with --place it will cause images that are smaller than the specified area to be scaled up to use as much of the specified area as possible.

--background <BACKGROUND>

Specify a background color, this will cause transparent images to be composited on top of the specified color. Default: none

--mirror <MIRROR>

Mirror the image about a horizontal or vertical axis or both. Default: none Choices: both, horizontal, none, vertical

--clear

Remove all images currently displayed on the screen.

--transfer-mode <TRANSFER_MODE>

Which mechanism to use to transfer images to the terminal. The default is to auto-detect. file means to use a temporary file and stream means to send the data via terminal escape codes. Note that if you use the file transfer mode and you are connecting over a remote session then image display will not work. Default: detect Choices: detect, file, stream

--detect-support

Detect support for image display in the terminal. If not supported, will exit with exit code 1, otherwise will exit with code 0 and print the supported transfer mode to stderr, which can be used with the --transfer-mode option.

--detection-timeout <DETECTION_TIMEOUT>

The amount of time (in seconds) to wait for a response form the terminal, when detecting image display support. Default: 10

--print-window-size

Print out the window size as <width>x<height> (in pixels) and quit. This is a convenience method to query the window size if using kitty +kitten icat from a scripting language that cannot make termios calls.

--stdin <STDIN>

Read image data from STDIN. The default is to do it automatically, when STDIN is not a terminal, but you can turn it off or on explicitly, if needed. Default: detect Choices: detect, no, yes

--silent

Do not print out anything to STDOUT during operation.

--z-index <Z_INDEX>, -z <Z_INDEX>

Z-index of the image. When negative, text will be displayed on top of the image. Use a double minus for values under the threshold for drawing images under cell background colors. For example, --1 evaluates as -1,073,741,825. Default: 0

--loop <LOOP>, -l <LOOP>

Number of times to loop animations. Negative values loop forever. Zero means only the first frame of the animation is displayed. Otherwise, the animation is looped the specified number of times. Default: -1

--hold

Wait for a key press before exiting after displaying the images.