Terminal Image Tools
Terminals can show pictures through graphics protocols such as Sixel, the Kitty graphics protocol and iTerm2 inline images, and fall back to half blocks or ASCII art where none of those exist.
The tools here view an image in place, convert and compress files, recolor wallpapers to match a theme, read and generate QR codes, draw ANSI art and turn source code or terminal output into an image for sharing. Each one takes paths and flags like any other command, so they fit into scripts and pipelines.
Below is a list of terminal tools that work with images.

astroterm
A terminal-based star map.
A terminal-based star map.

bit
Terminal ANSI Logo Designer & Font Library.
Terminal ANSI Logo Designer & Font Library.

carbon-now-cli
generate beautiful images of your code from right inside your terminal.
generate beautiful images of your code from right inside your terminal.

durdraw
Versatile ASCII and ANSI Art text editor for terminals.
Versatile ASCII and ANSI Art text editor for terminals.

gowall
A CLI tool to convert an image to any color-scheme.
A CLI tool to convert an image to any color-scheme.

imgcat
Display images and gifs in your terminal.
Display images and gifs in your terminal.

lsix
like "ls", but for sixel images.
like "ls", but for sixel images.

mapscii
The whole world in your console.
The whole world in your console.

mcat
Parse, convert & preview images, videos & markdown in your terminal.
Parse, convert & preview images, videos & markdown in your terminal.

menyoki
Screenshot/cast and perform ImageOps on the command line.
Screenshot/cast and perform ImageOps on the command line.

qrc
A QR code generator for text terminals.
A QR code generator for text terminals.

qrtool
A utility for encoding or decoding QR codes.
A utility for encoding or decoding QR codes.

runal
A creative coding environment for the terminal.
A creative coding environment for the terminal.

rusticon
A mouse driven SVG favicon editor for your terminal.
A mouse driven SVG favicon editor for your terminal.

silicon
create beautiful image of your source code.
create beautiful image of your source code.

termframe
Terminal output SVG screenshot tool.
Terminal output SVG screenshot tool.

textual-paint
MS Paint in your terminal.
MS Paint in your terminal.

tinifier
A CLI tool for compressing images using the TinyPNG service.
A CLI tool for compressing images using the TinyPNG service.

tortuise
A 3D gaussian splat viewer that works in your terminal.
A 3D gaussian splat viewer that works in your terminal.

tracker
A terminal-based real-time satellite tracking and orbit prediction application.
A terminal-based real-time satellite tracking and orbit prediction application.
Know any terminal tools that would be good for this list? Post a Tool here!