899828 - "GitHub Status" logo png is very pixelated after image is resized

Status: RESOLVED DUPLICATE of bug 897532

(Core :: Graphics, defect)

Description

[Chris Peterson [:cpeterson]]

STR:
1. Open https://status.github.com/
2. See that the "GitHub Status" logo looks very pixelated

This is a regression in Nightly 25 build 2013-07-23. Here is the pushlog from build 07-22 and 07-23:

https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=2268ff80683a&tochange=5ceea82a79c7

Comment 1

[Chris Peterson [:cpeterson]]

Attachment: Screenshot_2013-07-22_good.png

Good screenshot from build 07-22.

Comment 2

[Chris Peterson [:cpeterson]]

Attachment: Screenshot_2013-07-23_bad.png

Bad screenshot from build 07-23.

* Nick: could this pixelated image bug be a regression from your image resizing bug 700926? Your patch is within the pushlog regression range.

Comment 3

[Nick Cameron [:nrc]]

Not sure I am repro'ing this correctly, but it does seem to be due to 700926, and it also seems to be fixed by the patch I'm working on for 897787. But lets not dup this bug until we confirm that.

Comment 4

[Nick Cameron [:nrc]]

(In reply to Nick Cameron [:nrc] from comment #3)
> Not sure I am repro'ing this correctly, but it does seem to be due to
> 700926, and it also seems to be fixed by the patch I'm working on for
> 897787. But lets not dup this bug until we confirm that.

Nope on second look, it appears I just can't repro this bug with latest nightly. Tried on Windows and Linux. I always see the good version.

Comment 5

[Chris Peterson [:cpeterson]]

I can repro with the latest Nightly (07-30) on my MacBook Pro.

Comment 6

[Nick Cameron [:nrc]]

Well, I did what I should have done at first and checked the source code - turns out it is an img element, not a background-image, so it is highly unlikely that this regression is due 700926.

Do you have a retina screen? If so, perhaps it is a retina scaling bug?

Comment 7

[Chris Peterson [:cpeterson]]

No, I have a non-Retina screen.

Comment 8

[Chris Peterson [:cpeterson]]

Interestingly, on my Retina MacBook at home, the image is NOT pixelated (unless I manually disabled HiDPI with gfx.hidpi.enabled=-1).

Comment 9

[Timothy Nikkel (:tnikkel)]

Flipping gfx.content.azure.enabled to false seems to fix this, so this is probably caused by bug 896489.

Comment 10

[Joe Drew (not getting mail)]

This is because we don't have high quality image scaling enabled in the CoreGraphics moz2d backend, JEFF MUIZELAAR!!!

Comment 11

[Chris Peterson [:cpeterson]]

Attachment: DemetriMartin_twitter_avatar.png

This bug also caused Twitter avatar images, particularly ones with white backgrounds, to have have fuzzy pixel artifacts on their edges. See the attached screenshot.