Integrate pngquant when exporting to PNG

[eduardomozart]

I have a lot of issues to go through, so in order to make it easier for me to help you, I ask that you please try these things first

• Check out all the menus and keyboard shortcuts. Maybe the feature already exists?
• Try with the newest version from GitHub
• Read the documentation and FAQ, Known issues, Troubleshooting to see if the feature already exists
• See if someone already suggested this under Issues or Discussions

Description

It would be great if image captured from video could be optimized by pngquant after being exported. JPEG makes the captured image loose quality, and PNG files are so big, so compressing them using pngquant would make a file with a great size and quality.

[mifi]

next version will now allow setting a custom jpeg quality parameter. as for png, maybe we can use https://github.com/psych0der/pngquantjs

[Freso]

I personally use PNG to save/export lossless screenshots, but pngquant is specifically for lossy compression of PNGs. It may be “invisibly” lossy, but it’s lossy none‐the‐less. optipng (or the oxipng fork) seems like a better option to interface with… but I usually just run optipng myself.

If you decide to incorporate pngquant please make it clear that using that will result in a lossy screenshot.

[eduardomozart]

Talking with Shottr developer he said that there's no interface with PNGQuant itself and it's complicated to run executables on macOS Sandbox. Maybe optipng (or the oxipng fork that is used by ImageOptim) can be a better choice at all.

[mifi]

TBH now that we can adjust jpeg quality in losslesscut, I'm not sure what's the advantage of pngquant lossy png vs jpeg with 100% or so quality, so I'm inclined to close this

[eduardomozart]

JPEG has a larger file size than PNG relative to it's quality. JPEG files seem blurry and loose color, while PNG doesn't. Lossless Cut doesn't seem to optimize the PNG it produces and they have a higher size than they could without loosing visible quality. Using optipng would allow better quality screenshots with lower file size and pratically no noticeable quality loss.

[mifi]

I've added the suggestion here: #1908