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Issue 617880 link

Starred by 2 users

Issue metadata

Status: Available
Owner: ----
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Mac
Pri: 3
Type: Feature



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All images are pixel snapped, regardless of whether we need to

Reported by b...@photomania.net, Jun 7 2016

Issue description

UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36

Example URL:
http://codepen.io/bartzy/pen/jrbbLa

Steps to reproduce the problem:
1. use drawImage to draw an image on a subpixel boundary. Alternatively, transform the context to a subpixel boundary.
2. Image is drawn snapped to pixel boundary instead of interpolated at the edges.

What is the expected behavior?

What went wrong?
When drawing on a subpixel boundary, images should be interpolated at the edges. This helps a lot with animations and user interaction, making them look much less choppy.

Firefox and Safari (9) are interpolating as expected with the demo above.

Does it occur on multiple sites: N/A

Is it a problem with a plugin? No 

Did this work before? N/A 

Does this work in other browsers? Yes 

Chrome version: 50.0.2661.102  Channel: n/a
OS Version: OS X 10.11.4
Flash Version: Shockwave Flash 21.0 r0
 
Components: Blink
Cc: brajkumar@chromium.org
Labels: Needs-Feedback
Tested this issue on Mac OS 10.11.5 using chrome latest stable M51-51.0.2704.84 and observed no choppiness in the image while comparing both firefox and chrome. 

Reporter@ - Could you please upgrade your chrome to latest stable M51-51.0.2704.84 and recheck this issue. If issue still persists could you please provide screen-shot of the issue for better understanding.

Thanks!

Screen Shot 2016-06-08 at 3.29.20 PM.png
278 KB View Download
The issue is visible in your attached screenshot.

You can see, in FF, if you enlarge the screenshot to see its edges, that the edges are interpolated with the white background (1 pixel is brighter). In Chrome, the edges are crisp.

They should be crisp only if you draw on pixel boundaries, but in the demo I drew on subpixel boundary (i.e. floating point...)
Project Member

Comment 4 by sheriffbot@chromium.org, Jun 8 2016

Labels: -Needs-Feedback Needs-Review
Owner: brajkumar@chromium.org
Thank you for providing more feedback. Adding requester "brajkumar@chromium.org" for another review and adding "Needs-Review" label for tracking.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot
Components: -Blink Blink>Image
Cc: -brajkumar@chromium.org
Labels: -Pri-2 -Type-Compat -Needs-Review Pri-3 Type-Feature
Owner: ----
Status: Available (was: Unconfirmed)
It is an explicit decision in Chrome, for various reasons, to snap all images to pixel boundaries. For example, to draw at subpixel positions you need to resample the image everywhere, which is expensive and degrades quality if the image is otherwise not resized.

We face significant implementation challenges if we try to snap sometimes, when it has real value, but not others, when we would be resampling anyway.

I'm marking this as a feature request due to the scope of changes required to make it so. Basically we would only change this with a wholesale rethinking of the pixel snapping architecture. It's on out minds as something worth doing, but not soon.
Summary: All images are pixel snapped, regardless of whether we need to (was: drawImage does not interpolate on subpixel boundaries)
Project Member

Comment 8 by sheriffbot@chromium.org, Jul 3 2017

Labels: Hotlist-Recharge-Cold
Status: Untriaged (was: Available)
This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available. If you change it back, also remove the "Hotlist-Recharge-Cold" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot
Labels: -Hotlist-Recharge-Cold PaintTeamTriaged-20170707 BugSource-User
Status: Available (was: Untriaged)
Project Member

Comment 10 by sheriffbot@chromium.org, Jul 9

Labels: Hotlist-Recharge-Cold
Status: Untriaged (was: Available)
This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot
Status: Available (was: Untriaged)

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