1639574 - getImageData returns incorrect pixel information

Status: RESOLVED FIXED

(Core :: Graphics: Canvas2D, defect, P1)

Description

[Anton Lavrenov]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36

Steps to reproduce:

Try to getImageData of the red rectangle.

const ctx = canvas.getContext('2d');
ctx.fillStyle = 'rgb(255, 0, 0)';
ctx.fillRect(0, 0, 100, 100);
const data = ctx.getImageData(50, 50, 1, 1).data;
console.log(data[0], data[1], data[2]);

https://jsbin.com/jaqaqeboro/edit?js,console,output

Actual results:

getImageData returns incorrect pixel information. For me, it was (252, 13, 27).

Expected results:

The expected result is (255, 0, 0).

The same happening with any color I tried.
Online demo: https://jsbin.com/jaqaqeboro/edit?js,console,output

Comment 1

[Peter Magyari (Desktop QA)]

Hi Anton,

I was able to reproduce the issue on Firefox Nightly 78.0a1 and Firefox Beta 77.0b9 however Firefox 76.0.1 returns (255.0.0) correctly.

I've ran mozregression and got the following pushlog:

https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=ad3f58c996e59bc5ca0a0e6aac61c8f6a7e51096&tochange=6392325ec39e5cb10edd4aaaa4afb7a9f061b0b2

Bug 455077 seems to have introduced this issue.
Andrew, could you take a look?

Thank you for reporting!

Comment 2

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Andrew, could that be the same problem as I noticed with the drawSnapshot() API over on bug 1631089?

Comment 3

[Andrew Osmond [:aosmond] (he/him)]

Attachment: Bug 1639574 - Disable color management for CSS due to issues with canvas.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/fc441aa39120
Disable color management for CSS due to issues with canvas. r=jrmuizel

Comment 5

[Razvan Maries]

Backed out as requested: https://hg.mozilla.org/integration/autoland/rev/3fff015ec1c1314529cfaeb86fab0f86c7030657

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7f7e74f8b2e3
Disable color management for CSS due to issues with canvas. r=jrmuizel

Comment 7

[Andrew Osmond [:aosmond] (he/him)]

Comment on attachment 9151777 [details]
Bug 1639574 - Disable color management for CSS due to issues with canvas.

Beta/Release Uplift Approval Request

• User impact if declined: Canvas color management will be broken.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): This simply reverts our behaviour to what it was in the previous release. The pref is used in very few places, and the branches done as a result are very small (massages CSS colors to be more correct for display). There is very good test coverage on this.
• String changes made/needed:

Comment 8

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/7f7e74f8b2e3

Comment 9

[Henrik Skupin [:whimboo][⌚️UTC+1]]

I assume we should reopen this bug and should keep it blocking bug 455077? Or where should the remaining work for canvas be tracked?

Comment 10

[Pascal Chevrel:pascalc]

Comment on attachment 9151777 [details]
Bug 1639574 - Disable color management for CSS due to issues with canvas.

Driver for RC2, approved for uplift.

Comment 11

[Julien Cristau [:jcristau]]

https://hg.mozilla.org/releases/mozilla-release/rev/6c4a098b52dc

Comment 12

[Andrew Osmond [:aosmond] (he/him)]

I filed bug 1641229 to track the canvas issues.

Comment 13

[Andrew Osmond [:aosmond] (he/him)]

Attachment: Bug 1639574 - Increase fuzz for Android on reftest.

Comment 14

[Ryan VanderMeulen (PTO, back 6-April)]

https://hg.mozilla.org/releases/mozilla-release/rev/0e26956ce176