Jim's Depository

20 years of rewriting the same code

jpegapp - a tool for manipulating the application specific segments of a JPEG image.

Clean up camera metadata before publishing, preserve provenance in generated images, or inspect proprietary payloads without recompressing pixels. jpegapp offers direct control over JPEG APP segments for lightweight image-processing pipelines.

On adding alpha channels to JPEG images

Avoid PNG’s larger payloads when photos need irregular transparency: this browser-side technique pairs JPEG color data with an alpha mask using JavaScript and canvas, with a possible FlashCanvas path for legacy IE.

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