Hello,
I try to convert very large picture from PNG with alpha channel to WEBP .
This picture is really large, just near max resolution 16383x16383 but does not exceed maximum yet.
Paint net works with smaller pictures. This one stops at 52% and after a while throws exception. I have 20 GB free space on disc C.
The message:
I am sorry, actually Gimp throws same WebP error: 'partition is bigger than 512K'
Edit.
Okay, found the culprit:
-partition_limit int
Degrade quality by limiting the number of bits used by some macroblocks. Range is 0 (no degradation, the default) to 100 (full degradation). Useful values are usually around 30-70 for moderately large images. In the VP8 format, the so-called control partition has a limit of 512k and is used to store the following information: whether the macroblock is skipped, which segment it belongs to, whether it is coded as intra 4x4 or intra 16x16 mode, and finally the prediction modes to use for each of the sub-blocks. For a very large image, 512k only leaves room to few bits per 16x16 macroblock. The absolute minimum is 4 bits per macroblock. Skip, segment, and mode information can use up almost all these 4 bits (although the case is unlikely), which is problematic for very large images. The partition_limit factor controls how frequently the most bit-costly mode (intra 4x4) will be used. This is useful in case the 512k limit is reached and the following message is displayed: Error code: 6 (PARTITION0_OVERFLOW: Partition #0 is too big to fit 512k). If using -partition_limit is not enough to meet the 512k constraint, one should use less segments in order to save more header bits per macroblock. See the -segments option.
Is it possible to add more options to the Plugin?