What is this?
pngdeer is a lossy PNG compressor that automatically searches palette sizes from 2 to 256 colors and dithering options, scoring each result with a perceptual metric (SSIMULACRA2), then keeps the smallest file that still looks right. There's no quality slider to set yourself.
pngdeer is a lossy PNG compressor that automatically searches palette sizes from 2 to 256 colors and dithering options, scoring each result with a perceptual metric (SSIMULACRA2), then keeps the smallest file that still looks right. There's no quality slider to set yourself.Is this a command-line tool, a browser app, or both?Both. The same Rust code runs as a native CLI binary on macOS and Linux and is also compiled to WebAssembly for the in-browser version, producing identical output files.
Both. The same Rust code runs as a native CLI binary on macOS and Linux and is also compiled to WebAssembly for the in-browser version, producing identical output files.How do I get it running?Build the CLI from source with 'cargo build --release'; the binary ends up at target/release/pngdeer. The browser app can be used directly online or run locally using the toolchain listed in web/build.sh.
Build the CLI from source with 'cargo build --release'; the binary ends up at target/release/pngdeer. The browser app can be used directly online or run locally using the toolchain listed in web/build.sh.Do I need Rust installed to use it?To build the CLI from source you need Rust and Cargo, since the README only describes a source build. The browser version needs nothing beyond a browser, since it ships as WebAssembly.
To build the CLI from source you need Rust and Cargo, since the README only describes a source build. The browser version needs nothing beyond a browser, since it ships as WebAssembly.Can I set the compression quality myself?No, there's no quality slider: pngdeer always targets roughly what TinyPNG would produce for that image, capped at 90 on the SSIMULACRA2 scale, so you can't dial it higher or lower.
No, there's no quality slider: pngdeer always targets roughly what TinyPNG would produce for that image, capped at 90 on the SSIMULACRA2 scale, so you can't dial it higher or lower.Does the command-line tool run on Windows too?The README only lists macOS and Linux for the CLI build; Windows isn't mentioned, so the browser (WebAssembly) version is the way to use pngdeer there.
The README only lists macOS and Linux for the CLI build; Windows isn't mentioned, so the browser (WebAssembly) version is the way to use pngdeer there.Does the browser version upload my images anywhere?No, images are compressed entirely on your device; nothing is sent to a server.
No, images are compressed entirely on your device; nothing is sent to a server.How much smaller are the files compared to TinyPNG?On a 180-image benchmark, pngdeer's files are 8-12% smaller than TinyPNG's at matching quality for the median image, and still 6-9% smaller when checked with a different metric (butteraugli) that the search never looks at.
On a 180-image benchmark, pngdeer's files are 8-12% smaller than TinyPNG's at matching quality for the median image, and still 6-9% smaller when checked with a different metric (butteraugli) that the search never looks at.How does pngdeer pick a palette instead of using a fixed setting?For each image it tries palette sizes from 2 to 256 colors, with and without Floyd-Steinberg dithering and a couple of other variants, scores every candidate with SSIMULACRA2 in Oklab color space, and keeps the smallest file that still meets the quality bar.
For each image it tries palette sizes from 2 to 256 colors, with and without Floyd-Steinberg dithering and a couple of other variants, scores every candidate with SSIMULACRA2 in Oklab color space, and keeps the smallest file that still meets the quality bar.How does it stay fast on large images?It runs the palette search on a downscaled preview and only checks the chosen settings at full size. The browser version handles images up to 40 megapixels; the CLI can go higher.
It runs the palette search on a downscaled preview and only checks the chosen settings at full size. The browser version handles images up to 40 megapixels; the CLI can go higher.What are similar projects?lightcraft, liteparse, genact, pdfcraft, spritefusion-sprite-normals, xerj, TurboBench, photosuite
lightcraft, liteparse, genact, pdfcraft, spritefusion-sprite-normals, xerj, TurboBench, photosuiteWhich topics is it in?png, compression, webassembly, wasm, image-processing, browser, offline, command-line, utility, benchmark, local-first, command-line-tool
png, compression, webassembly, wasm, image-processing, browser, offline, command-line, utility, benchmark, local-first, command-line-tool