PureJsImage v0.17.0

Added

• Added an explicit optional Rust/WASM WebP accelerator with scalar and SIMD modules for VP8 row
  color conversion, VP8L predictor and color transforms, lossless encode transforms, and lossy
  RGBA or gray to YUV420 conversion. Measured RGB input keeps the existing paired-row TypeScript
  conversion because it is faster end to end. The TypeScript codec still owns RIFF parsing, entropy
  coding, limits, metadata, and bounded row orchestration. Module or kernel failures fall back to
  the TypeScript path. The pull-request corpus workflow now forces scalar and SIMD WebP runs and
  checks exact decode pixels, deterministic encode bytes, and actual kernel use.
• Added a pull-request-only Imazen corpus workflow for JPEG, PNG, WebP, TIFF, GIF, and BMP. The
  workflow checks out the corpus at a pinned commit, runs every file in an isolated process, fails
  on per-file behavior changes, and uploads the generated reports for review.
• Added forced scalar and SIMD Imazen lanes for JPEG, PNG, and WebP. Eligible inputs must execute
  the selected WASM kernels. JPEG and PNG decode pixels remain exact, deterministic scalar and PNG
  encoders require byte parity, and the SIMD JPEG AAN encoder keeps its existing PSNR and size gate.

Changed

• Refreshed the stable-codec, cross-library web-codec, JPEG, PNG, and WebP WASM benchmarks, package
  metrics, result index, README charts, website charts, and accelerator benchmark pages after the
  current codec and runtime work.
• Node orientation and rotation now use lazy chunked memory by default. Pass
  { temporaryFiles: true } as the second argument to createImageLibrary() to opt into a lower
  process-RSS file spool. The opt-in path probes file creation, writing, reading, and truncation
  before consuming image rows. Failed setup or later file writes fall back to memory. The previous
  64 MiB Node memory fallback ceiling has been removed; normal image limits still apply.
• The optional WebP WASM accelerator now uses four-pixel SIMD for VP8L color transforms, fuses the
  common inverse color, predictor, and subtract-green row sequence into one call, and specializes
  uniform mode-11 prediction. Seven paired 4000x3000 lossless WebP trials reduced the median from
  617.90 ms to 518.50 ms, with exact output and a 2.00% peak RSS reduction.
• The optional Rust/WASM JPEG encoder now uses a separable f32 AAN transform, precomputed
  reciprocal quantization factors, and four-pixel SIMD RGB and RGBA compositing and color
  conversion. Unused SIMD scratch arrays were removed. Seven paired end-to-end trials reduced the
  png-to-jpeg workflow median by 24.58% with the output quality, size, and correctness gates
  unchanged.
• The optional Rust/WASM JPEG decoder now skips the full IDCT for DC-only blocks. Seven paired
  end-to-end trials reduced the jpeg-to-png workflow median by 5.64% with exact output
  correctness and a 0.46% peak RSS reduction.
• JPEG WASM exactness now covers DC-only inverse-transform half-integer boundaries and scalar
  encoder values immediately below a positive half-integer. The Rust decoder now validates the
  end-of-scan marker after its final MCU while still allowing legal bytes after EOI.
• Rust/WASM JPEG and PNG builds now reserve a bounded 128 KiB stack, trap on unexpected panics,
  and reject out-of-bounds or overlapping JPEG buffers before reading or writing memory. Initial
  accelerator memory remains within four WebAssembly pages.
• The Imazen corpus command now accepts --baseline <directory> and exits with an error when a
  file changes outcome, completed stage, structured error, diagnostic, child exit code, or signal.
  Timing and machine metadata remain outside the comparison.