termimage

Protocols

Kitty graphics

The Kitty graphics protocol transmits a full PNG payload via APC escape sequences, chunked at 4 096 bytes of base64 each. The terminal decodes and GPU-composites the image.

  • q=2 suppresses per-chunk ACK responses, maximizing throughput.
  • Image is always re-encoded as PNG before transmission regardless of source format.
  • Terminals: Kitty, Ghostty, WezTerm ≥0.29.

Sixel

DEC Sixel encodes the image as bands of 6-pixel-high strips with a palette of up to 256 colors. termimage uses median-cut color quantization.

\x1bPq          ← enter sixel mode
#0;2;R;G;B      ← color definitions
#0<data>$       ← band data + carriage return
-               ← next band
\x1b\\           ← exit
Warning

Sixel throughput is lower than Kitty for large images because the terminal must parse each character rather than receiving a binary blob. Keep MaxWidth ≤ 800 for smooth rendering.

Half-block

Unicode ▀ (U+2580, UPPER HALF BLOCK) encodes two vertically stacked pixels per character cell using foreground (top) and background (bottom) 24-bit ANSI color escapes.

Works on any terminal with UTF-8 and COLORTERM=truecolor. No terminal extensions required.

\x1b[38;2;R;G;Bm   ← foreground = top pixel
\x1b[48;2;R;G;Bm   ← background = bottom pixel
▀
\x1b[0m             ← reset