Imgcli MCP server

imgcli — command-line image conversion & processing in C

ImageMagick's power, ffmpeg's syntax, zero dependencies. A tiny C binary that converts, resizes, crops, filters, and composites images — PNG, JPEG, BMP, TGA, GIF, PPM, QOI — driven by an ffmpeg-style filtergraph. No system libraries; compiles anywhere a C11 compiler exists.

⚡ ~8× faster than ImageMagick on common resize/filter ops, in a 232 KB

single binary (~470× smaller) — see the benchmarks. A lightweight

alternative to ImageMagick convert or ffmpeg for still images.

# Convert + resize + filter in one pass:
imgcli -i photo.jpg -vf "scale=1024:-1,grayscale,contrast=1.2,gblur=1.5" out.png

What it does: format conversion · resize / scale · crop · pad · rotate · flip · brightness / contrast / saturation / gamma / hue · grayscale · sepia · invert · threshold · box & Gaussian blur · sharpen · Sobel edge detect · emboss · custom convolution kernels · alpha-composite overlay · draw boxes · solid fills.

Design: the same paradigm as ffmpeg — decode → normalize to one common frame format (RGBA) → run a comma-separated filtergraph → encode by output extension.

Benchmarks

imgcli vs ImageMagick on an Apple Silicon Mac (single-threaded, warm cache). Reproduce with make && bench/bench.sh — see bench/RESULTS.md for the full method and caveats.

ImageMagick is a far broader 16-bit/HDRI toolkit with 200+ formats; imgcli is a lean 8-bit pipeline that wins on speed, size, and startup — the shape that matters when an agent or script spawns one process per task.

Dependencies & formats

The default build is dependency-free — a single binary that links only the system C library (libc). Decoding/encoding is handled by the bundled, public-domain stb and qoi single-header libraries, compiled directly in. Nothing to apt install, no shared libraries, no version hell.

Other formats that can be implemented in plain C (e.g. TIFF) will also be built in and keep the binary dependency-free.

• Built-in formats — no dependencies: PNG, JPEG, BMP, TGA, GIF, PPM, QOI.

cannot be decoded without large external libraries (libwebp, libavif, libheif, libjxl); there is no public-domain single-header decoder for them and they are not practical to hand-roll. If imgcli adds these, it will be strictly via opt-in build flags (e.g. make WEBP=1) that link those libraries.

• Formats that need external libraries — opt-in only: WebP, AVIF, HEIC, and JPEG XL

**The "zero dependencies" claim applies to the default build, and always will —

opt-in format libraries are never compiled into it.** A build that enables such

a flag is, by definition, no longer dependency-free, and that trade-off is

stated at the point you opt in.

Why it's structured this way

Shortened. The full README is on GitHub.