- From: <bugzilla@jessica.w3.org>
- Date: Sat, 12 Feb 2011 00:08:26 +0000
- To: public-html-bugzilla@w3.org
http://www.w3.org/Bugs/Public/show_bug.cgi?id=12044 Summary: This is a new feature request. Request overview: Give developers an option to disable a context's image smoothing (ie, anti-assailing). Problem: When scaling up images, most user agents smooth the output. This is fine for most use cases, but is undesirabl Product: HTML WG Version: unspecified Platform: Other URL: http://www.whatwg.org/specs/web-apps/current-work/#top OS/Version: other Status: NEW Severity: normal Priority: P3 Component: HTML Canvas 2D Context (editor: Ian Hickson) AssignedTo: ian@hixie.ch ReportedBy: contributor@whatwg.org QAContact: public-html-bugzilla@w3.org CC: mike@w3.org, public-html-wg-issue-tracking@w3.org, public-html@w3.org Specification: Section: http://www.whatwg.org/specs/web-apps/current-work/complete.html#top Comment: This is a new feature request. Request overview: Give developers an option to disable a context's image smoothing (ie, anti-assailing). Problem: When scaling up images, most user agents smooth the output. This is fine for most use cases, but is undesirable when "pixel-perfect" output is desired. Unfortunately, there is nothing in the spec that allows a user to turn off this smoothing. I ran into this issue when I was creating a canvas based image editor. In particular, it more or less torpedoed my first attempt at creating a zoom feature. Simply put, when I tried to show a "zoomed in" view of a smaller base image, the "pixels" of the zoomed view were anti-assailed and bled into each other. The effect was ugly and (more importantly) non-representative of the actual image being edited, which nicely defeated the purpose of an image editor. Currently the only solution is to roll your own scaling algorithms based on imageData, which is less than ideal. Use cases: Any application where a developer needs "pixel perfect" scaling. Examples include image editors, pixel art, pixel animations, and cases where developers want to avoid any computational overhead associated with smoothing. Solution: Codify an existing implementation (see below). My image editor looked great in Firefox! A more complicated solution could allow a developer to specify a specific smoothing algorithm. Something along the lines of "context.smoothing('bicubic')." Existing implementation: "Gecko 1.9.2 introduced the mozImageSmoothingEnabled property to the canvas element; if this Boolean value is false, images won't be smoothed when scaled. This property is true by default." Source: https://developer.mozilla.org/en/Canvas_tutorial/Using_images#Controlling_imag e_scaling_behavior Posted from: 65.185.139.106 -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the QA contact for the bug.
Received on Saturday, 12 February 2011 00:08:28 UTC