- From: Leonard Rosenthol <lrosenth@adobe.com>
- Date: Wed, 13 Mar 2013 10:17:02 -0700
- To: Rik Cabanier <cabanier@adobe.com>, HTMLWG WG <public-html@w3.org>
I understand all that Rik - but it doesn't address my comment. You are constructing an image from an array of pixel data. You can't do that unless you either hardcode/fix the format of the array (eg. RGB) _OR_ you have a parameter that defines the format (RGB vs. BGR vs. ARGB etc.) Leonard On 3/13/13 5:15 PM, "Rik Cabanier" <cabanier@adobe.com> wrote: >Hi Leonard, > >imageData is a class that already exists [1]. This proposal just adds a >constructor so you can create one yourself instead of having to use >calls like 'createImageData' or 'getImageData' [2]. >The spec defines the pixel layout. > >Canvas just support RGB; it has no concept of color management. There is >also no support for index images. >I've made a proposal to add masking on the canvas mailing list and will >post the request to publish it when I have more time. > >1: http://www.w3.org/TR/2dcontext/#imagedata >2: http://www.w3.org/TR/2dcontext/#pixel-manipulation > > >> -----Original Message----- >> From: Leonard Rosenthol >> Sent: Wednesday, March 13, 2013 1:05 AM >> To: Rik Cabanier; HTMLWG WG >> Subject: Re: Proposal: ImageData constructor >> >> Wouldn't you also need to know information about the array's contents? >> For example, is it always RGBA? What if I have ARGB data? Or just RGB >>w/o >> an alpha channel? Or BGR? Of course, that assumes just simple sRGB >>data. >> (I am going to ASSUME that profiled or indexed image data is handled >>via the >> ImageData class after instantiation). >> >> Leonard >> >> On 3/13/13 5:12 AM, "Rik Cabanier" <cabanier@adobe.com> wrote: >> >> >All, >> > >> >Ken Russell proposed the following addition to the 2D canvas: >> > >> >[Constructor(Uint8ClampedArray data, double sw, double sh)] >> > interface ImageData { >> > readonly attribute unsigned long width; >> > readonly attribute unsigned long height; >> > readonly attribute Uint8ClampedArray data; >> > }; >> > >> >The new constructor allows you to construct a new ImageData object from >> >an Uint8ClampedArray. The imageData object simply assigns: >> >- width = sw >> >- height = sh >> >- data = data >> > >> >Before this API, you had to construct the imagedata with a width and >> >height and then copy the pixels between the arrays manually. >> > >> >If there are no objections to this, I will add this to the canvas 2d >>spec. >> > >> >Rik
Received on Wednesday, 13 March 2013 17:17:29 UTC