1698413 - Screenshot feature does not use subpixel antialiasing

Status: NEW

(Core :: Graphics, defect)

Description

[cholismo]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0

Steps to reproduce:

Take a screenshot of any page (with a text rendered with subpixel antialiasing instead of grayscale) with the inbuilt feature and check the result.

Actual results:

You get a screenshot with blurry text because grayscale AA is used instead.

Expected results:

Take another screenshot following the classic method (press "Print Screen" key and paste on any image editor) and it will be identical to the captured page.

Comment 1

[Raluca Popovici, Desktop QA]

Attachment: fxscreenshot.png

Comment 2

[Raluca Popovici, Desktop QA]

Attachment: screenshotOS.png

Comment 3

[Raluca Popovici, Desktop QA]

Hi,
I was able to reproduce this issue on my machine win 7x64 with Nightly 88. There is a slightly difference(blurry) between Fx screenshots feature and the classic method (CTRL + Print Screen and paste on image editor). I will attach 2 screesnhots(one from Fx and another with classic method)

Comment 4

[Jeff Muizelaar [:jrmuizel]]

Is this a regression?

Comment 5

[cholismo]

(In reply to Jeff Muizelaar [:jrmuizel] from comment #4)

Is this a regression?

Most probably yes, I don't remember this happening in the past. I have tested the feature with Webrender disabled and it does the same. In any case, the screenshot should be identical to the source (rendering mode included) as it happens with the classic copy & paste method.

Comment 6

[Bob Hood [:bhood]]

Does this remain an issue with the current version of Firefox?

Comment 7

[cholismo]

(In reply to Bob Hood [:bhood] from comment #6)

Does this remain an issue with the current version of Firefox?

Yes, I have just checked with Firefox 104.0.2 (64-bit) on Windows 7 and the text is still using greyscale AA when you make an screenshot with Firefox instead of "Print Screen" + paste on editor.

Comment 8

[Jeff Muizelaar [:jrmuizel]]

Can you run mozregression to figure out what change caused this to regress?

Comment 9

[cholismo]

Attachment: mozregression.png

I ran mozregression 4.0.18 because the latest version (5.0) crashes on Windows 7. The results are on the screenshot, it seems the first version with this bug was mozilla-central build 2020-12-15.

Thanks.

Comment 10

[Timothy Nikkel (:tnikkel)]

pushlog from that screenshot
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=8d6972b0b89b1303dbcfb566e16b1144303af83e&tochange=914398229db8d83caf1e3501c3d760f800c8d1e9