[MohammadHijjawi97]

Summary

Mask from Alpha took the image's last band as the mask. For an image without an alpha channel that is not alpha: it is the blue channel for RGB, the gray values for L, and palette indices for P (the saved "mask" is then even a P-mode image). The node now converts to RGBA and reads the A channel, so an opaque image gives a solid white mask and palette transparency is honored. RGBA/LA input is unchanged.

Before (RGB pixels red, green, dark blue): mask [0, 0, 64]
After: mask [255, 255, 255]

Related Issues / Discussions

None.

QA Instructions

• uv run --no-sync pytest tests/app/invocations/test_image.py: 20 passed. Without the fix, the RGB case returns [0, 0, 64] and the palette case saves a P-mode image.
• uv run --no-sync pytest tests/app/invocations/test_image_manipulation_invocations.py tests/app/invocations/test_mask_bounding_box.py: passed.
• uv tool run ruff@0.11.2 check / format --check on the changed files: clean.

Review

The node's fields and version are unchanged.

Checklist

• The PR has a short but descriptive title, suitable for a changelog
• Meaningful regression coverage added / updated where needed; obsolete tests/code removed
• Persisted-state and API changes include required migrations / compatibility validation
• Relevant performance/efficiency opportunities considered; material claims have evidence
• Material review findings resolved and relevant checks rerun
• Documentation added / updated (if applicable)
• Updated What's New copy (if doing a release after this PR)

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[JPPhoto]

@MohammadHijjawi97 Thanks for the submission.

Findings/issues:

• invokeai/app/invocations/image.py:244: For RGB/L/P inputs, tomask now returns opaque pixels instead of the previous last-band values, but its decorator at image.py:233 remains version 1.2.2. Saved workflows with that version appear current in webv2 (invokeai/frontend/webv2/src/features/workflow/core/document.ts:431), so users get no update warning as their masks change. A version bump is required when a node's functionality, inputs, or outputs change substantially; in this case, a minor version bump is acceptable to serve as an alert to users. This does not need an additional test.

[MohammadHijjawi97]

@JPPhoto thanks for the review. I bumped tomask to 1.3.0 in the decorator and in invokeai/frontend/api/openapi.json, so saved workflows using 1.2.2 now get the update warning (commit 061f8ff).

[JPPhoto]

@MohammadHijjawi97 One case that I think this needs to preserve original behavior for is input mode 'L' (not 'LA') images. The mask in that case should be treated as before rather than using the alpha channel; that was the original intent of the node, IIRC, and your changes break it. You can confirm this by looking at the workflow builders in invokeai/frontend/webv2.