[Feature]: Convert non-lossy images to lossy Webp on drop.

[FullBleed]

Describe the Problem

Users are often using bloated file types (png, tif, bmp, etc.) without knowing that converting to a lossy compression format (like Webp) would save them a ton of space. This also reduces the size of the campaign files significantly and speed up auto saves and transfers to clients.

The Solution you'd like

When dropping an asset, have a "default on" check box to convert non-lossy images to a lossy webp images. Put the image quality conversion setting (0-100) in preferences>application. I'd suggest a 70% default.

Alternatives that you've considered.

At least warn users when importing non-lossy images that they should convert the images to webp... and then let them figure out how on their own. ;)

Additional Context

This does not address the problem of users using way more resolution than necessary and will not reduce memory usage.

[kwvanderlinde]

I don't really use WebP a lot (ever) so I had to see just how good this could be. I manually converted my campaign full of PNG assets to WebP, trying both lossless and 70% quality lossy. Results:

	PNG (original)	WebP Lossless	WebP Lossy 70%
Asset total on-disk	173.9 MB	87.1 MB	17.1 MB
Campaign size on-disk	157.5 MB	88.9 MB	18.8 MB

If that kind of result is normal, and if there's no real downside to using WebP, then I'd like to see us use WebP as the serialized format for image assets. It would clearly help a lot for heavier campaigns. Only thing is that I'd prefer to keep assets lossless by default if the incoming format is lossless. Then let users explicitly say they want to allow lossy conversion at some preferred quality.

[FullBleed]

I don't really use WebP a lot (ever) so I had to see just how good this could be. I manually converted my campaign full of PNG assets to WebP, trying both lossless and 70% quality lossy. Results:
PNG (original) WebP Lossless WebP Lossy 70%
Asset total on-disk 173.9 MB 87.1 MB 17.1 MB
Campaign size on-disk 157.5 MB 88.9 MB 18.8 MB

If that kind of result is normal, and if there's no real downside to using WebP, then I'd like to see us use WebP as the serialized format for image assets. It would clearly help a lot for heavier campaigns. Only thing is that I'd prefer to keep assets lossless by default if the incoming format is lossless. Then let users explicitly say they want to allow lossy conversion at some preferred quality.

Definitely typical. WebP is such a nice format. I wouldn't fight the "lossless by default" approach so long as we have some kind of easy method to convert to lossy. As you can see, the lossless-to-lossless savings is good... while lossless-to-lossy is incredible (and, to my eyes, I can hardly tell the 70-80% rate unless I go pixel peeping.)

Note: If you default to lossless, you'll need to make an exception for jpgs (which is a lossy format without an alpha channel). Converting a jpg to a non-lossy WebP will actually blow things up considerably.

Quick test on a large JPG map (9500x7000):

Original JPG : 9072kb
WebP Lossy (70%) : 5945kb
WebP Lossless: 68637kb

I don't know what the jpg quality setting was for the original image (probably 70-80%)... but a 7.5x increase in size would be the exact opposite of what we're going for here. ;)