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name: image-preparation description: "Prepare and validate DreamCraft3D reference images, sidecar maps, and preprocessing prerequisites." disable-model-invocation: true metadata: disco-role: operating license: NOASSERTION

Image Preparation

Use this sub-skill when a task is about getting a single reference image ready for DreamCraft3D: background removal, RGBA/depth/normal sidecars, recentering, caption sidecars, or diagnosing why data.image_path cannot be loaded.

Read first

• Read references/image-inputs.md for the expected file layout, preprocessing workflow, CLI arguments, and how sidecars feed the stage configs.
• Read references/troubleshooting.md when preprocessing or stage startup fails because images, sidecars, model checkpoints, CUDA, or optional captioning dependencies are missing.
• Run or adapt scripts/validate_preprocessed_image.py when you need a safe sidecar check that does not import torch, run Omnidata, remove backgrounds, download models, or mutate the input image.

When to use this sub-skill

Use it for requests like:

• "Prepare my image for DreamCraft3D."
• "Why does single-image-datamodule say it cannot find depth/normal?"
• "Check whether mushroom_log_rgba.png is ready for the configs."
• "Explain preprocess_image.py --recenter and output names."

Workflow

1. Determine the intended input image stem. DreamCraft3D stage configs normally use an RGBA image path such as load/images/mushroom_log_rgba.png.
2. Check sidecars before launching training:
   • the RGBA input must exist and should have an alpha channel,
   • configs with requires_depth: true need a sibling <stem>_depth.png,
   • configs with requires_normal: true need a sibling <stem>_normal.png,
   • captions are optional and only created when captioning is requested.
3. If sidecars are missing, decide whether the user wants full preprocessing. Full preprocessing uses background removal, Omnidata depth/normal checkpoints, and CUDA by default; do not run it as a cheap validation step.
4. Route back to generation-pipeline only after the image path and required sidecars are ready or the limitation is explicitly documented.

Safe validator

From a DreamCraft3D checkout, point the bundled validator at the intended RGBA file:

python <skill-dir>/sub-skills/image-preparation/scripts/validate_preprocessed_image.py \
  --image load/images/mushroom_log_rgba.png --require-depth --require-normal

Use --json for machine-readable output and --allow-missing when you want a non-failing report while planning fixes.

Decision points

• If the user has a plain RGB/JPEG/PNG image, preprocessing is needed before the main stages.
• If the user already has _rgba, _depth, and _normal files, prefer validating sidecars over rerunning expensive models.
• If the task is about checkpoint chaining or launch commands, route to generation-pipeline.
• If the task is about Zero123++ multiview images or LoRA texture boosting, route to bootstrapped-texture.
• If the task is about mesh export or metrics, route to export-and-evaluation.