BIC v0.2.1

Added

• bic inspect <image> [--json]: sizes of PNG, oxipng, WebP lossless and BIC
  for one image, for build tools.
• @proteo5/bic-build, a build step and plugins that store flat graphics
  (charts, logos, icons) as BIC and serve them in the browser through a Service
  Worker, under their original URLs:
  • bic-build <input> <output> command;
  • a Vite plugin (@proteo5/bic-build/vite);
  • a webpack 5 plugin (@proteo5/bic-build/webpack).
    The conversion rule: at least 10 % smaller than the best lossless alternative,
    never JPEG, never more than 4096 colors. Thresholds can be changed.
• @proteo5/bic-runtime, the BIC decoder in JavaScript (5.7 KiB gzip with zstd).
• The package downloads the bic release binary for its platform on install and
  checks it against the release checksums.

BIC v0.2.0

The BIC2 format replaces BIC1, and BIC1 files can no longer be read. Re-encode
them from the original images.

BIC targets images with large solid areas: screenshots, UI, diagrams,
charts, icons and pixel art. It offers little or no advantage on photographs.
JPEG sources are stored unchanged.

Added

• BIC2 coding:
  • a palette for images with up to 256 colors;
  • a subtract-green color transform;
  • row prediction, either fixed (none or up) or chosen per row (none, left,
    up, average, Paeth, MED).
• Exhaustive encoder: it tries every transform and predictor combination
  in parallel and keeps the smallest. The default Zstandard level is now 19.
• Near-lossless mode (--max-error N) in the style of JPEG-LS: every
  decoded sample is within N of the original. Lossless candidates are tried
  too, so flat graphics stay exact.
• Original-file storage: a PNG, JPEG, WebP or HEIF source that is smaller
  than BIC's own encoding is stored unchanged, so a .bic file is never larger
  than its original plus 32 bytes. --transcode disables this.
• ICC profiles are stored in the container and written back to PNG
  output.
• EXIF orientation is applied when reading sources.
• --fast-decode: skips per-row prediction for faster opening, at the cost
  of slightly larger photographs.
• bic-view, a viewer without a console window:
  • File > Open (Ctrl+O) and File > Save as BIC (Ctrl+S), with saving in the
    background;
  • smooth resampling when the window is resized;
  • errors shown in a dialog;
  • used by the Windows file association.
• bic compare: benchmarks against PNG, oxipng, WebP lossless and QOI on
  files or folders, with CSV output and PSNR for near-lossless runs.
• bic verify --max-error for checking near-lossless files.
• Library API: encode_file, encode_source, read_source,
  encode_rgba_with_metadata, decode_with_metadata, storage, and
  DecodeLimits for untrusted input.
• cli feature (on by default) for the programs. With
  default-features = false the library depends only on anyhow, image,
  heic-rs and zstd.
• Testing: property-based tests and cargo-fuzz targets. CI runs on Linux
  and Windows, with fuzzing and a synthetic-corpus benchmark.

Changed

• On the project's benchmarks (geometric mean against oxipng), flat graphics
  went from 1.316 to 0.755. Lossless photographs went from 1.849 to 0.837, but
  that comparison excludes strong photographic codecs.
• Lossless decoding processes whole rows with vectorizable loops.
• The decoder's default memory limit is 512 MiB, set with --max-alloc-mib.

Removed

• --quant-step, --smooth-tolerance and --residual, replaced by
  --max-error.
• is_png_fallback, replaced by storage.

Fixed

• Block partitioning only ever used 256-sample blocks.
• A malformed file with an inverted channel range could crash the decoder.
• Payloads that decompressed past their declared size were not rejected.
• Encoding an empty image with --png-fallback failed.
• Decoding to JPEG failed on RGBA images.