Why a local image batch can fail—and how to recover

A small file can become a large image in memory

Compressed bytes are not the same as decoded memory. A 4000 × 3000 photo has 12 million pixels. A basic four-byte-per-pixel buffer alone is about 48 MB before output canvases, thumbnails and browser overhead. Several full-resolution copies can use considerably more.

Dama processes images sequentially and limits inputs to 24 megapixels, 20 MB per file, 20 images and 100 MB total. Outputs are capped at 12 megapixels per image and 100 MB per batch. These are product safeguards, not a guarantee that every low-memory device can handle a full batch.

If a file is rejected before preparation

The tool checks image headers rather than trusting a filename extension. Renaming picture.heic to picture.jpg does not convert it. Open the original in a trusted editor and export JPG, PNG or static WebP. GIF, SVG, HEIC and animated PNG/WebP are outside the supported scope.

A damaged or incomplete file may have a familiar extension but lack valid image data. Try opening it outside the browser. If it cannot be opened there, recover the original rather than repeatedly trying the same broken export.

If processing slows or stops

1. Cancel the run; cancellation takes effect after the current decode or encode operation finishes.
2. Keep or download any successful outputs, then try fewer photos.
3. Reduce output dimensions and close other memory-heavy tabs.
4. Test the failing file by itself. Large pixel dimensions matter even if the compressed size is small.
5. Try a current browser with image bitmap and canvas support.
6. Keep originals outside the browser. An open tab is not a backup.

If the ZIP is missing

A browser may block a download or ask where to save it. Check its downloads list first. Dama says “download requested” because a web page cannot verify that you saved and extracted a file.

If building an archive fails, use Save image on individual results or prepare a smaller batch. PNG outputs can become large; a suitable JPG or WebP may reduce memory use when your destination supports it. The 100 MB output limit is checked as results are created, so some files can succeed and later files can fail.

If saved settings do not return

Private browsing, storage restrictions, cleared site data, a different browser profile, or a different device can explain missing settings. The workspace should still function with defaults. A failed save displays a message instead of silently promising persistence.

Do not rely on browser navigation to preserve or clear a batch. Use Clear batch when finished, and keep originals separately. Browser and operating-system caches are outside Dama’s control; local processing is not a promise of secure erasure of every trace.