What this opens on
The JPG panel at 2×, clean-up Light, saving JPG at quality 92. The order of the chain is the point:
| Step | What it does |
|---|---|
| 1. Clean up (Light) | softens 8-pixel block steps and colour blotches in the source |
| 2. Enlarge (Lanczos 3) | spreads the cleaned pixels to the new size |
| 3. Encode JPG | at the quality you chose, measured in bytes |
A 640 × 480 JPEG at 2× becomes 1280 × 960 — four times the pixels, so the block grid the eye picks up at 100% is now sixteen pixels across. Clean-up Light is what keeps it from being the first thing anyone sees.
Where this falls down
- Heavy compression stays visible.Light clean-up softens blocks; it cannot restore what a very low quality setting threw away.
- Saving JPG again is a second loss.Small at quality 90 and above, but real. Choose PNG in Export to avoid it.
Questions people ask
- Why deblock before enlarging?
- A JPEG stores the picture in eight-pixel blocks and its colour at reduced resolution. Enlarged as they are, the block edges become sixteen- or thirty-two-pixel steps. Clean-up Light softens those steps and colour blotches first and leaves real texture alone; after enlarging is too late.
- How big will the JPG be?
- Press Measure and the full result is encoded at the chosen quality in this tab and its exact byte count shown — not an estimate. The same is read back from the file after you save.
- What is chroma subsampling, and which does this use?
- Storing colour at lower resolution than brightness. The page reads it from the encoded file's own header and names it: browsers' JPEG encoders commonly write 4:2:0, colour at half resolution each way. It is read, not assumed.
- Should I save as PNG instead?
- If the enlarged picture is going to be edited again, yes: PNG adds no second loss. JPG is right when the destination wants a JPG or a small file.
Better fit?
- A rough small photoOpens with the clean-up pass on, because a 600-pixel JPEG carries more than a picture.
- Increase JPG size in KBClear a form's minimum file size honestly: quality first, then pixels, bytes measured from the saved file.
- Enlarge a PNGTransparency-first: premultiplied resampling with no dark fringe, edge-guided for logos, PNG or WebP out.
- Denoise before upscalingDecide when noise reduction should precede enlargement and when it will erase useful texture.
