Re: Advice on extending CanvasRenderingContext2D to support Depth Streams

On Thu, Oct 23, 2014 at 6:41 AM, Kostiainen, Anssi <
anssi.kostiainen@intel.com> wrote:

> [+public-canvas-api, -public-html-comments]
>
> Hi Canvas 2D Editors,
>
> We’re looking for your feedback with regard to extensions to the
> CanvasRenderingContext2D, see [1].
>
> In addition, couple of clarifying meta questions:
>
> * The bleeding edge and maintained W3C Editor’s Draft of the Canvas 2D
> spec is at [2], correct? There are quite a few W3C Editor’s Drafts with
> different URLs [3]. Please confirm whether [2] is the canonical URL to be
> referenced in other specs.
>

There are indeed quite a few versions. The W3C version that will include
new features is here: http://www.w3.org/html/wg/drafts/2dcontext/master/


> * What is the preferred mailing list for feedback and discussion related
> to [2]? All the W3C’s Canvas 2D Context specs ask to "e-mail feedback to
> public-html-comments@w3.org” yet it appears public-canvas-api (this list)
> would be a more appropriate. Correct?
>

For W3C, public-canvas-api@w3.org is the right one to discuss new features.
In general, the right mailing list is the one where you get most of the
browser developers to participate:-)


> [1]
> http://w3c.github.io/mediacapture-depth/#canvasrenderingcontext2d-interface
> [2] http://www.w3.org/html/wg/drafts/2dcontext/master/
> [3] http://damowmow.com/temp/canvas-specs
>
>
> > Begin forwarded message:
> >
> > Date: 9 Oct 2014 00:04:32 EEST
> > From: Rob Manson <roBman@buildAR.com>
> > To: <ian@hixie.ch>, <public-html-comments@w3.org>
> > Cc: "public-media-capture@w3.org" <public-media-capture@w3.org>,
> "Kostiainen, Anssi" <anssi.kostiainen@intel.com>, "Hu, Ningxin" <
> ningxin.hu@intel.com>
> > Subject: [mediacapture-depth] Advice on extending
> CanvasRenderingContext2D to support Depth Streams
> >
> > Hi Ian, Rik, Jatinder, Jay and Tom,
> >
> > we're working on the W3C Media Capture Depth Stream Extension[1] that
> adds support for depth cameras[2] to the getUserMedia() API. As part of
> that we've been exploring the different media processing pipelines for the
> Web Platform that will let us extract and post process the data from these
> media streams.
> >
> > The difference with the depth streams is that they are Uint16Array based
> instead of the normal Uint8ClampedArray viewed as an RGBA ArrayBufferView.
> To help treat Depth Streams like other Media Streams we have taken an
> approach that packs 16 bits losslessly into existing codes[3].
> >
> > For WebGL we are proposing a minimal extension to texImage2D and
> texSubImage2D where they are passed an HTMLVideoElement that includes a
> Depth Stream based track.
> >
> > For the 2D canvas based pipeline we have proposed[4] a parallel model to
> ImageData called DepthData. It is very similar to ImageData except the
> .data is a Uint16Array and it adds some new CanvasRenderingContext2D
> methods like .getDepthData() that will return a DepthData object.
> >
> > We're currently drafting this specification in it's own extension
> spec[1], the FPWD was published 7 October 2014. Now we'd ask for your
> feedback on the design to make sure we integrate cleanly with the
> CanvasRenderingContext2D to allow the extension to be integrated at a later
> stage if so desired.
> >
> > Thanks.
> >
> > roBman
> >
> > [1] http://w3c.github.io/mediacapture-depth/
> > [2] https://www.w3.org/wiki/Media_Capture_Depth_Stream_Extension
> > [3]
> http://web4.cs.ucl.ac.uk/staff/j.kautz/publications/depth-streaming.pdf
> > [4]
> http://w3c.github.io/mediacapture-depth/#canvasrenderingcontext2d-interface
> >
> >
>
>
>