Add a way to compress PNG images when uploading

[saschanaz]

Summary

I just set my profile header image from Snipping Tool on Windows, which generates PNG image by default. That caused a big 1 MB header. I don't want to let any visitors to download that much just for a silly header image.

It seems PNG is never compressed per the following code, if I'm reading right:

misskey/packages/client/src/scripts/upload.ts

Lines 19 to 23 in c0c23b1

	const compressTypeMap = {
	'image/jpeg': { quality: 0.85, mimeType: 'image/jpeg' },
	'image/webp': { quality: 0.85, mimeType: 'image/jpeg' },
	'image/svg+xml': { quality: 1, mimeType: 'image/png' },
	} as const;

Maybe PNG should also be compressed by default since there is an explicit flag to opt-out?

[tamaina]

Client compression of png is disabled because apng cannot be processed (correctly, the processing implementation was put off).

#8216

[tamaina]

MEMO

How to identify whether webp image is static or animated?