Show HN: I built an image optimization tool based on Google's new Jpegli encoder (opens in new tab)

It took a bit of time for me to respond because I wanted to make sure I wrote down the info in a nice detailed way. I will update the descriptions on the website to include the information I am proving here to give visitors a better understanding of the options. To be clear, I am not an expert on all this image coding stuff. I just wanted to make a simple tool to let people try out Jpegli because I thought it was interesting even though I don't know so much about the topic.

Progressive Rendering There are 3 options on the website. None, Basic and Enhanced. There correspond respectively to options 0, 1 and 2 for the JXL_ENC_FRAME_SETTING_PROGRESSIVE_DC option [1].

"Set the progressive mode using lower-resolution DC images for VarDCT. Use -1 for the encoder default, 0 to disable, 1 to have an extra 64x64 lower resolution pass, 2 to have a 512x512 and 64x64 lower resolution pass."

So "Basic" provides 1 scan and "Enhanced" provides 2 scans. Here is a detailed description on progressive loading: https://www.thewebmaster.com/progressive-jpegs/

DCT Method I can't really find documentation about DTC Method in libjxl but the options seems to be very similar to the options offered in mozjpeg [2]. They have a detailed explanation on that page I referenced which I won't all copy here. Seems like slow integer is the preferred method as the others are marked as legacy. Maybe I should just remove the options? From my testing the slow integer method has slightly worse compression but it is accurate.

XYB colorspace TBH, the library I am using only supports a few color spaces and it does not include XYB and I have not looked into it much further. Also as you can see I did not really bother to add colorspace settings in general but I might do it later.

[1] https://libjxl.readthedocs.io/en/latest/api_encoder.html#_CP...

[2] https://github.com/mozilla/mozjpeg/blob/6c9f0897afa1c2738d72...

It's on there now