The quality parameter doesn't affect PNG output. When converting the same HEIC file with different quality values (0.3, 0.5, 0.7), the resulting PNG files have identical file sizes.
Test result:
- quality: 0.3 → size: 14472794 bytes
- quality: 0.7 → size: 14472794 bytes (same)
This appears to be because canvas.toBlob() ignores the quality parameter for PNG format (as per MDN docs). The documentation shows PNG supports quality parameter, but it doesn't actually work.
Could you please clarify this in the documentation or provide an alternative way to control PNG file size?
Thank you very much!
The
qualityparameter doesn't affect PNG output. When converting the same HEIC file with differentqualityvalues (0.3, 0.5, 0.7), the resulting PNG files have identical file sizes.Test result:
This appears to be because
canvas.toBlob()ignores thequalityparameter for PNG format (as per MDN docs). The documentation shows PNG supports quality parameter, but it doesn't actually work.Could you please clarify this in the documentation or provide an alternative way to control PNG file size?
Thank you very much!