I'm experiencing an issue when setting metadata and cover art on an Opus file using MusicBrainz Picard. After adding metadata, I encounter the following warning from 

opusinfo:

WARNING: Invalid picture parameters in METADATA_BLOCK_PICTURE comment 37 (stream 1): width (500), height (492), depth (0), and colors (0) MUST either be set to valid values or all set to 0

It seems that when cover art is embedded, Picard is setting some of these parameters (e.g., width and height) without setting others (e.g., depth and colors). According to the Opus specification, these values should either be valid or all set to 0, but the current behavior creates an invalid combination.

Steps to Reproduce:
1. Open an Opus file in Picard.
2. Add metadata and cover art to the file.
3. Save changes and check file with `opusinfo`.
4. Observe the warning about invalid picture parameters.

This issue may cause compatibility problems for some players and tools due to non-compliant metadata.