17577 2012-06-22 14:08:58 +0000 Problem: How to manipulate pixels of an image that can then be affected by a transformation. Example: Load an image. Change pixels by increasing red value. Display image with a rotation. Result: Cannot be done. As far as I can tell there is no way to use 2012-08-23 19:59:54 +0000 1 1 1 Unclassified HTML WG HTML Canvas 2D Context unspecified Other other RESOLVED WONTFIX http://www.whatwg.org/specs/web-apps/current-work/#top P3 normal --- 1 contributor cabanier cabanier mike public-html-admin public-html-wg-issue-tracking public-html-bugzilla oldest_to_newest 69344 0 contributor 2012-06-22 14:08:58 +0000 Specification: http://www.w3.org/TR/2dcontext/ Multipage: http://www.whatwg.org/C#top Complete: http://www.whatwg.org/c#top Comment: Problem: How to manipulate pixels of an image that can then be affected by a transformation. Example: Load an image. Change pixels by increasing red value. Display image with a rotation. Result: Cannot be done. As far as I can tell there is no way to use pixel manipulation on a loaded image. - There is no mechanism to manipulate pixels in an image - There is no mechanism to 'put' pixels from ImageData into an image - There is no mechanism to apply a transform to ImageData - There is no mechanism to drawImage ImageData I'm either ignorant of a method or this is a serious short-coming. I recognize that the canvas may have no business altering image pixels, but some other mechanism needs to exist to apply transformations to manipulated canvas pixels. I would like to see a putImageData have a flag to indicate if transformations should apply, or, better yet, be able to drawImage(ImageData,x,y); Thank you, derek@upwithabang.com Posted from: 174.3.214.112 User agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20100101 Firefox/13.0.1 70382 1 contributor 2012-07-18 07:23:58 +0000 This bug was cloned to create bug 17960 as part of operation convergence. 72521 2 cabanier 2012-08-21 23:41:16 +0000 You need to create an offscreen canvas that you load your image in if you want to manipulate its pixels. So: - create a HTMLImageElement, load the image - create a canvas element that has the same dimensions as the image - call drawimage to put the image into the canvas - call getimagedata, manipulate the pixels and call putimagedata The offscreen canvas can now be rotated/scaled/clipped on your screen canvas. 72629 3 cabanier 2012-08-23 19:59:54 +0000 EDITOR'S RESPONSE: This is an Editor's Response to your comment. If you are satisfied with this response, please change the state of this bug to CLOSED. If you have additional information and would like the Editor to reconsider, please reopen this bug. If you would like to escalate the issue to the full HTML Working Group, please add the TrackerRequest keyword to this bug, and suggest title and text for the Tracker Issue; or you may create a Tracker Issue yourself, if you are able to do so. For more details, see this document: http://dev.w3.org/html5/decision-policy/decision-policy.html Status: WONTFIX