Upscaling
Upscale enlarges an image to a higher resolution. You can just enlarge it (a few seconds), or redraw it once in tiles after enlarging to add more detail; at 1× the size stays the same and only detail is added.
Basic steps
Section titled “Basic steps”- Choose “Upscale” as the refine mode.
- Choose an “Upscaler” and a “Scale”.
- Decide whether to turn on “Add detail”.
- Press “Upscale” (or “Enlarge” when Add detail is off).
Upscaler
Section titled “Upscaler”| Option | Description |
|---|---|
| ESRGAN-family models | For example 4x-UltraSharp. Much better than a simple resize |
| Simple resize (no model) | Enlarges without a model |
Put upscale models in upscale_models in CoCo’s model folder, or a folder in your main model folder categorized as “Upscale models”.
1×, 1.5×, 2×, 3× or 4×. The long side is limited to 4096 pixels; you’ll be told if it would be larger.
1× keeps the size and is for adding detail only: detail is added at a larger size, then the image is scaled back to its original size. It takes about as long as 2× with Add detail. At 1× with Add detail off, choose an upscaler; otherwise the image won’t change.
Add detail
Section titled “Add detail”| Setting | Description |
|---|---|
| On | After enlarging, the image is split into overlapping tiles of about 1 megapixel and each is redrawn. Detail increases and seams aren’t visible. Takes longer |
| Off | Enlarges only, without redrawing; done in a few seconds |
Adding detail uses the model and sampling settings chosen under “From the image / From Generate” in the left panel. Recommended amounts:
| Level | Description |
|---|---|
| Subtle | Adds a little detail; the image barely changes |
| Moderate | The usual strength; lines and textures become clearer |
| Strong | The most detail, but small things that weren’t in the original may appear |
Measured on an RTX 5080, enlarging from 1024 to 2048 pixels with Add detail takes about 47 seconds. Larger scales mean more tiles and more time, but graphics memory use doesn’t increase.
Transparent backgrounds
Section titled “Transparent backgrounds”Images with a transparent background (for example after background removal) can be upscaled directly; the background stays transparent.
Batch upscaling
Section titled “Batch upscaling”Select several images in the library, press “Batch refine” and choose upscaling to process them together, optionally adding detail.