ToolJovia
Images

Image Compositing Workbench

Combine ordered local raster layers with controlled blending, positions and opacity.

✓ Browser-local processing
Static PNG, baseline JPEG or simple VP8/VP8L WebP; each≤8MiB,4,000,000 pixels and4,096px per side. Progressive JPEG, VP8X/animated WebP, APNG and compressed PNG profiles/text or PNG EXIF are excluded.

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How to use Image Compositing Workbench

Combine ordered local raster layers with controlled blending, positions and opacity. A JSON layer plan references selected file indexes, pixel offsets, opacity and one of six Canvas blend operations. destination-in lets a raster layer act as an alpha mask; the result is one flattened PNG.

  1. Provide ordered raster files, layer json: file,x,y,opacity,mode, canvas width, canvas height.
  2. Choose the supported mode and run the tool. Review its assumptions and any reported errors.
  3. Copy the result or download a separate output; reset to clear the current form.

Good to know

  • Static PNG, baseline JPEG or simple VP8/VP8L WebP; each≤8MiB,4,000,000 pixels and4,096px per side. Progressive JPEG, VP8X/animated WebP, APNG and compressed PNG profiles/text or PNG EXIF are excluded. Full container structure is checked before native decoding; this is not a complete codec validator. Browser decoding/export can still reject a file or change color profiles. Output is a fresh PNG without original container metadata.
  • Up to5 input files/20MiB,8,388,608 aggregate source pixels and4,194,304 canvas pixels and10 planned layers. Decode/composite one bitmap at a time.
  • Fixed blend operations only; no arbitrary CSS/HTML, uploaded SVG, editable project format or managed-color guarantee.
  • Inputs are processed on this device and are not automatically saved or uploaded.

Common questions

How does the mask layer work?

Use destination-in for a layer whose alpha should retain the current destination. Transparent mask pixels remove destination pixels; source-over instead paints the layer normally.

Does this change my original input?

No. The tool returns a separate result. Review that output before using it in another application.

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