Imported from cocosip/go-dicom-codecs (AGENTS.md). Install upstream with npx skills add cocosip/go-dicom-codecs. Copyright stays with the author.

Repository Guidelines

Project Structure & Module Organization

This is a Go module for DICOM image codecs. Core interfaces and shared error types live in codec/. Codec implementations are grouped by family: jpeg/ for baseline, extended, lossless, and lossless14sv1 JPEG; jpegls/ for lossless and near-lossless JPEG-LS; and jpeg2000/ for JPEG 2000, HTJ2K, wavelet, MQC, tier-1, tier-2, and validation code. Usage samples are under examples/. Test fixtures and reference inputs are in test-data/ and package-local testdata/ directories. Keep new tests beside the package they verify.

Build, Test, and Development Commands

• go mod download downloads module dependencies.
• go mod verify checks cached dependencies against go.sum.
• go test ./codec/... ./jpeg/... ./jpeg2000/... ./jpegls/... ./examples/... runs the main test set.
• go test -race -short -timeout 30m -coverprofile=coverage.out -covermode=atomic ./codec/... ./jpeg/... ./jpeg2000/... ./jpegls/... ./examples/... mirrors CI coverage and race checks.
• go vet ./codec/... ./jpeg/... ./jpeg2000/... ./jpegls/... ./examples/... runs static vet checks.
• golangci-lint run --timeout=10m ./codec/... ./jpeg/... ./jpeg2000/... ./jpegls/... ./examples/... runs the configured lint suite.

Coding Style & Naming Conventions

Use standard Go formatting: run gofmt on edited files and keep imports organized. Package names should be short, lowercase, and match the codec area, such as lossless, baseline, htj2k, or codestream. Exported identifiers need clear doc comments when they are part of the public API. Prefer table-driven tests for codec matrices and keep transfer syntax UIDs or marker constants named descriptively.

Testing Guidelines

Tests use Go's built-in testing package. Name files with _test.go and test functions as TestXxx. Add focused round-trip, boundary, malformed-input, and conformance tests for codec changes. Use go test -run TestName ./path/... for targeted work, then run the broader package set before submitting.

Commit & Pull Request Guidelines

Recent history uses short conventional-style subjects, often with emoji prefixes, such as fix: ..., style: ..., build(deps): ..., and ci(release): .... Keep commits scoped and imperative. Pull requests should describe the codec behavior changed, list verification commands run, and call out compatibility risks, especially for DICOM transfer syntax registration, lossy/lossless output, or performance-sensitive paths. Include benchmark output when touching hot encode/decode loops.

Cache Directory

• The .cache directory is used for project build and package caching, and is already added to .gitignore. During testing and debugging, relevant caches can be configured under this directory. No additional cache directories should be created.