Multi-stage pipelines declared in YAML: generate, edit (cross-product),
remove_bg, and upscale stages executed sequentially in a single GPU
session. Every intermediate artifact (image + metadata JSON) is saved
to {output_dir}/{stage_id}/ for full traceability.
Data routing:
- generate: list of prompts → list of images (1:1 per item)
- edit: fan-out cross-product (each input × each prompt)
- remove_bg / upscale: 1:1 passthrough
Resume: outputs that already exist are skipped. Use --force to re-run
everything — lets you add items to a stage without regenerating.
Examples: examples/portrait.yaml, examples/backgrounds.yaml
Adds `vnasset upscale` CLI command, `VnAssetsSession.upscale()` / `.upscales()`
session methods, and a standalone `vnassets.upscale` module following the
existing remove-bg pattern.
Uses Real-ESRGAN RRDBNet with RealESRGAN_x4plus_anime_6B (~17 MB,
auto-downloaded). A 256x256 warmup tile at load time eliminates ~80s of
first-run CUDA JIT compilation on ROCm. Steady-state: ~1.8s per 1024->2048
upscale on Strix Halo. The upsampler is lazy-loaded on first call and coexists
with SDXL/Qwen in the same session.
Works around a basicsr/torchvision API incompatibility (rgb_to_grayscale moved
in torchvision 0.20+) with a 3-line module shim in upscale.py.
rembg with ONNX Runtime on CPU was chosen over BiRefNet: the latter
requires deform_conv2d which crashes on ROCm bfloat16 and runs at 40s
in float32. rembg delivers 0.23s per 1024x1024 image, no GPU deps,
and isnet-anime is trained specifically on anime images — exactly the
target domain.
CLI and session API both support single-image and batch (plural-first)
modes, reusing one model session across files.
- Consolidate TECH_SPEC into README as single source of truth
- Remove TECH_SPEC.md (375-line README covers everything)
- Fix architecture diagram: Qwen transformer ~5GB → ~20GB (20B params)
- Remove unimplemented CLI flags from docs: --sampler, --scheduler, --clip,
--vae, --turbo (these don't exist in the actual code)
- Replace 'FP8 native compute' claim with actual FP8→BF16 conversion
- Replace 'peft' with actual diffusers native LoRA loading
- Move aspirational optimizations (VAE overlap, shared encode) to Future
- Resolve stale Open Questions; keep torch.compile as Future item
- Move 'Persistent model session' and 'Qwen Image Edit' from Future to
implemented status with documented API
- Update performance numbers with actual measured session+flash numbers
- Document flash attention path alongside matmul fallback
- Simplify data flow diagram, remove ComfyUI-only kontext_scale concept
- Remove dead doc links (sdxl-generation.md)
- Support (word:weight), [word], ((nested)) syntax
- Support BREAK for conditioning chunking (.and() translation)
- Use CompelForSDXL (modern API, avoids deprecation)
- Add --raw flag to bypass weighting and fall back to plain encoding
- Update README with Prompt Syntax section and examples
- Add docs/comfyui-prompt-style.md with design doc
