Adjust Cover¶
Use Adjust Cover to resize or change the format of pictures embedded
in the selected audio files. It changes all embedded pictures in each file;
it does not change a separate cover.jpg alongside the music.
Shrink oversized covers¶
- Keep original copies and select a few practice files.
- Choose Actions → Actions (Quick)…, then Adjust Cover.
- Keep Image format as Original.
- Check Resize cover, set Size in pixels to
600, choose Maximum size and Scale proportionally. - Choose Apply action, then inspect the cover dimensions.
A 1200 × 800 image becomes 600 × 400. A 300 × 300 image keeps its size. The picture's cover type and description are retained.
Format and quality settings¶
| Setting | Choices and effect |
|---|---|
| Image format | Original, JPEG, or PNG |
| Quality | Best = 100, High = 90, Medium = 75, Low = 50, or Custom |
| Quality (0–100) | A whole number used when encoding JPEG |
| Resize cover | Off initially; enables the size and scaling settings |
Original retains a writable original format: JPEG, PNG, GIF, BMP or WebP. If OpenTag cannot write that original format, choose JPEG or PNG. PNG preserves transparency; JPEG does not. Quality does not control PNG compression or resize dimensions.
If the format and dimensions remain the same, the picture stays byte for byte unchanged. Changing JPEG quality alone therefore does not recompress an otherwise unchanged JPEG. Choose the format and resizing operation to match the actual goal, and check the resulting file size rather than assuming a particular quality number guarantees it.
Size policy and scaling¶
Size in pixels accepts 1–32768. The policy selects which dimension is compared with that number; scaling selects the resulting shape.
| Size policy | Meaning |
|---|---|
| Maximum size | Reduce images whose larger side exceeds the size; leave images already within it unchanged |
| Minimum size | Match the smaller side to the size, enlarging or reducing as necessary |
| Scaling | What happens when resizing is needed |
|---|---|
| Scale proportionally | Keep the aspect ratio |
| Scale to square | Stretch to exactly the requested width and height |
| Crop to square | Keep proportions, fill the requested square, and crop the excess around the center |
With a 1200 × 800 cover and size 600:
| Policy and scaling | Result |
|---|---|
| Maximum + proportional | 600 × 400 |
| Minimum + proportional | 900 × 600 |
| Maximum + square | 600 × 600, stretched |
| Maximum + crop | 600 × 600, cropped |
Maximum size does not force a small image into a square: a 300 × 200 image already within a maximum of 600 keeps its shape in every scaling mode. Use the policy deliberately when a player needs a square image.
Gotchas¶
- Enlarging cannot restore image detail. Keep a high-resolution original outside the audio file if it may be needed later.
- Cropping and JPEG conversion can lose information. Copy the files first; inspect Edit → Undo for recorded changes in the current session.
- An invalid image or unsupported output format reports an error. Check the operation result before processing the rest of the library.