Feature Request/Inquiry: Additional WebP Compression Options

[Saijin-Naib]

I've been using Curtail to work on my JPEGs under Linux, and appreciate the recent addition of WebP compression/transcode.

In looking at compressor.py, I note that a number of cwebp options I use for single-file transcoding locally are absent.

My question is twofold:

1. Would additional options be welcomed?
2. Would they need UI integration to be added?

My proposed additional options for cwebp (and accompanying explanation):

• sharp_yuv helps prevent color shift when the colorspace conversion happens
• pass 10 helps to ensure the best compression efficiency by iterating on the file 10 times
• alpha_filter best tries to do the best quality of prediction before compression on the alpha channel
• hint photo tunes the encoder for my subject material (photographs) to help improve PSNR
• af is experimental, but tunes the filters automatically. Subjectively, this has been wonderful
• pre 2 is a pseudo-random dithering which should help prevent artifacting

[JumperLuko]

It would be very useful if I could convert from a format like jpg to webp, with the lack of a function to convert between different formats the app has no use for me. I would be grateful if there was a day

[Saijin-Naib]

@Huluti

Do you have any insight into questions 1 and 2 that I posed in the OP?

If you are good with my suggested options, and the answer to 1 is yes, then I can open a PR.

If the answer to 2 is yes, then I'll likely need help doing that part of it as I don't understand gtk/pygtk at all.

[Saijin-Naib]

Just following up again