Skip to content

CLAUDE.md

Latest commit

 

History

History
46 lines (32 loc) · 1.77 KB

CLAUDE.md

File metadata and controls

46 lines (32 loc) · 1.77 KB

CLAUDE.md

Build and test commands

# Build (default features: png + jpeg)
cargo build --release

# Build with libjpeg-turbo FFI (requires system headers)
cargo build --release --features jpeg-turbo

# Build core scaler only, no codec dependencies
cargo build --release --no-default-features

# Run all tests
cargo test

# Run tests without default features
cargo test --no-default-features

# Run tests using scalar (non-SIMD) code paths on x86_64
cargo test --features force-scalar

# Run imgscale CLI
cargo run --release --bin imgscale -- WIDTH HEIGHT input.jpg [output.jpg]

# Run benchmarks
cargo run --release --bin benchmark -- image.png

Key design decisions

  • Streaming API: OilScale processes one scanline at a time to minimize memory. Call slots() to know how many input lines to push_scanline() before calling read_scanline().
  • Separable convolution: horizontal and vertical passes are independent.
  • sRGB correctness: all interpolation happens in linear light space using precomputed lookup tables.
  • Premultiplied alpha: RGB channels are premultiplied by alpha before interpolation, then unpremultiplied on output.
  • Adaptive kernel width: downscaling widens the kernel to cover all input pixels and prevent aliasing. Taps = 4 * (in_dim / out_dim), always even.
  • Dimension constraint: both dimensions must scale in the same direction (both up or both down). Range: 1 to 1,000,000.

Release process

  1. Update version references in README.md
  2. Update version in Cargo.toml
  3. Commit, tag (e.g., git tag v0.3.0), and push with git push && git push --tags

A GitHub Actions workflow (.github/workflows/release.yml) triggers on v* tags, runs tests, publishes to crates.io via trusted publishing, and creates a GitHub release.