Re: Advice on extending CanvasRenderingContext2D to support Depth Streams

Hi Rik,

Why not just post to the public-canvas-api test and in the subject include
[Canvas 1] or [Canvas 2] as applicable.

Hopefully Canvas 1 won't be too much longer. We don't need another list to
monitor.

Rich


Rich Schwerdtfeger



From: Rik Cabanier <cabanier@gmail.com>
To: "Kostiainen, Anssi" <anssi.kostiainen@intel.com>
Cc: "public-canvas-api@w3.org" <public-canvas-api@w3.org>, "Hu,
            Ningxin" <ningxin.hu@intel.com>, Rob Manson
            <roBman@buildar.com>
Date: 10/23/2014 12:04 PM
Subject: 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


  >
  >