This is a feature release with lots of additional polish and some new API.

Thanks to everyone who chipped in with issues and code. Special thanks to @AnonymouX47 for helping out with the grid implementation and for going above and beyond with QA and bugfixing in general.

• Added terminal probing. Currently we can determine geometry, colors and sixel capabilities this way. This supplements the existing heuristics.

• The internal terminal database and heuristics were refactored for clarity, with new API added to simplify the configuration process.

• I/O is now threaded, resulting in improved responsiveness and pipelining.

• New option: --grid=WxH, --grid=[auto|on|off] or -g. This lays out multiple images in a grid for easy browsing.

• New option: --label=[on|off] or -l. Labels each image with its filename. Works in both continuous and grid layouts.

• New option: --probe=[auto|on|off]. Controls whether to actively probe the terminal. Can take a real number denoting how long to wait for a response.

• Sixel quality improved significantly. The quantizer was reimplemented with modern algorithms (#174), and blue noise dithering was introduced (#238).

• The new blue noise dithering is also available in symbols mode, and can be turned on with --dither noise. It can be turned off with --dither none.

• Numerous small improvements were made to sixel handling:

  • Terminal cursor placement quirks are now represented and handled.
  • Images can now cover their cell extents completely.
  • Workaround for animations "walking up the screen" on quirky terminals.

• The JPEG XL loader was improved with optional memory mapping and better container support (@oupson).

• Enabled wildcard expansion in Windows builds (#266).

• Added completions for the fish shell (@folliehiyuki) and updated those for zsh (@sstark).

• Bug fixes: #111 Provide auto detection of background for perception of transparency (found by @acxz). #228 Sixel capability not detected in foot + tmux (found by @amigthea). #236 Ghostty shows pwd/lock indicator when using Chafa (found by @edrozenberg). #238 Sixel image quality significantly different from img2sixel and ImageMagick (found by @rashil2000). #239 Chafa leaves echo on (found by @veltza). #245 JPEG file not recognized (found by @ploum). #246 Examples using deprecated functions (found by @sechshelme). #249 Sixel detection doesn't set default values (found by @veltza). #254 -t 1 doesn't work with -f iterm (@AnonymouX47). #255 Animations scroll/walk up the screen (found by @AnonymouX47). #265 Enable Kitty image protocol for Warp (found by @SohamP2812). #266 On Windows, in a cmd.exe window, filename wildcard expansion is broken (found by @garoto). #273 -t 1 messes up some images (found by @AnonymouX47). #274 -f {kitty,iterm} swaps BG color channels for SVG (found by @AnonymouX47). #278 Images not always padded to cell boundary (found by @veltza). [unfiled] Fix broken bashisms resulting in logic failure (@eli-schwartz). [unfiled] Small leak in chafa_canvas_print_rows() (@korei999). [unfiled] Uninitialized histogram in nearest-neighbor interp.