Bug 452844

Summary:	Enhance webP export when "Text" profile is selected, enabling "Sharp YUV" webP option
Product:	[Applications] krita	Reporter:	Rafael Linux User <rafael.linux.user>
Component:	File formats	Assignee:	Krita Bugs <krita-bugs-null>
Status:	REPORTED ---
Severity:	wishlist	CC:	amy, rafael.linux.user
Priority:	NOR
Version First Reported In:	5.0.5
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Option "Use Sharp YUV" is here Text pattern as example Squoosh web result

Description Rafael Linux User 2022-04-22 08:20:44 UTC

SUMMARY
When I was exporting to webP from PNG an image with sharp text, I realized that outline of the text is not as sharp as the original even without compression. I tried even the "Text" preset that Krita shows under "Options, General" while exporting to webP, but exported image text was never so sharp as original PNG.
Asking at webP developers, they told me there is an advanced option called "Sharp YUV", and as you can see in next thread, it works very well. 

https://bugs.chromium.org/p/webp/issues/detail?id=567#c3

Could you implement that option in Krita export dialog or enable it when user select "Text" preset?

Thank you

Comment 1 amyspark 2022-08-23 19:24:03 UTC

Hi! I added "Use Sharp YUV" a year ago, it's in the Advanced tab of the WebP export plugin. Can you try 5.1 or latest nightly and see if it works for you?

As for the preset itself, we could override the Text preset's own configuration with this option, though it'd need further discussion.

Comment 2 amyspark 2022-08-23 19:24:36 UTC

Created attachment 151531 [details]
Option "Use Sharp YUV" is here

Comment 3 Rafael Linux User 2022-08-26 11:15:21 UTC

Hi again

I needed some time to test it and to make a good text example that anyone can use to see if "Use Sharp YUV" is working right (I attach it to this reply).

As previously, in Krita, I selected "Text" profile, and it automatically enabled "Use Sharp YUV". I export at 50% and 75% quality. Unfortunately, there is absolutely no difference in enabling or not that option. I don't know reason, but it far away of working like in "https://squoosh.app" and enabling there "Sharp RGB -> YUV" (I'll attach screenshot where you can see my text pattern processed in Squoosh without and with "Sharp RGB ->YUV" option enabled).

Comment 4 Rafael Linux User 2022-08-26 11:17:09 UTC

Created attachment 151612 [details]
Text pattern as example

I created this pattern using exactly color and background more affected by this issue

Comment 5 Rafael Linux User 2022-08-26 11:21:29 UTC

Created attachment 151613 [details]
Squoosh web result

WebP on both sides. Left side, without "Sharp ..."  enabled. Right side, with "Sharp ..." enabled. Difference is noticeable.

Comment 6 Bug Janitor Service 2022-08-27 04:36:16 UTC

Thanks for your comment!

Automatically switching the status of this bug to REPORTED so that the KDE team
knows that the bug is ready to get confirmed.

In the future you may also do this yourself when providing needed information.

Comment 7 Rafael Linux User 2022-08-27 08:53:49 UTC

(In reply to Bug Janitor Service from comment #6)

> Automatically switching the status of this bug to REPORTED so that the KDE team knows that the bug is ready to get confirmed.
> In the future you may also do this yourself when providing needed information.

I usually report about an issue confirmed by me. In many cases, no one ask me for more info and automatically this platform change status to NEEDSINFO and I can't do nothing about, cause I gave all the information necessary to corroborate the problem and no one asked any more questions. What can I do in such cases?

Thank you