[gow] (2) Changes to <canvas> color correction requirements

git-svn-id: http://svn.whatwg.org/webapps@1196 340c8d12-0b0e-0410-8428-c7bf67bfef74
whatwg · Feb 3, 2008 · b382946 · b382946
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diff --git a/index b/index
@@ -24,7 +24,7 @@
 
    <h1 id=html-5>HTML 5</h1>
 
-   <h2 class="no-num no-toc" id=working>Working Draft &mdash; 2 February 2008</h2>
+   <h2 class="no-num no-toc" id=working>Working Draft &mdash; 3 February 2008</h2>
 
    <p>You can take part in this work. <a
     href="http://www.whatwg.org/mailing-list">Join the working group's
@@ -17687,7 +17687,7 @@ notes on what would need to be defined for dashed lines:
 
   // support methods
   function FillPlasma(data, color) { ... }
-  function AddCload(data, x, y) { ... }
+  function AddCloud(data, x, y) { ... }
 </pre>
   </div>
 
@@ -17804,26 +17804,45 @@ notes on what would need to be defined for dashed lines:
 
   <p>The <code><a href="#canvas">canvas</a></code> APIs must perform colour
    correction at only two points: when rendering images with their own gamma
-   correction information onto the canvas, to convert the image to the color
-   space used by the canvas (e.g. using the <code
+   correction and color space information onto the canvas, to convert the
+   image to the color space used by the canvas (e.g. using the <code
    title=dom-context-2d-drawImage><a href="#drawimage">drawImage()</a></code>
    method with an <code><a
    href="#htmlimageelement">HTMLImageElement</a></code> object), and when
    rendering the actual canvas bitmap to the output device.
 
-  <p>Thus, in the 2D context, colors used to draw shapes onto the canvas will
-   exactly match colors obtained through the <code
+  <p class=note>Thus, in the 2D context, colors used to draw shapes onto the
+   canvas will exactly match colors obtained through the <code
    title=dom-context-2d-getImageData><a
    href="#getimagedata">getImageData()</a></code> method.
 
   <p>The <code title=dom-canvas-toDataURL><a
    href="#todataurl">toDataURL()</a></code> method must not include color
-   space information in the resource returned.
+   space information in the resource returned. Where the output format allows
+   it, the color of pixels in resources created by <code
+   title=dom-canvas-toDataURL><a href="#todataurl">toDataURL()</a></code>
+   must match those returned by the code
+   title="dom-context-2d-getImageData">getImageData() method.
 
   <p>In user agents that support CSS, the color space used by a <code><a
    href="#canvas">canvas</a></code> element must match the color space used
    for processing any colors for that element in CSS.
 
+  <p>The gamma correction and color space information of images must be
+   handled in such a way that an image rendered directly using an <code><a
+   href="#img">img</a></code> element would use the same colors as one
+   painted on a <code><a href="#canvas">canvas</a></code> element that is
+   then itself rendered. Furthermore, the rendering of images that have no
+   color correction information (such as those returned by the <code
+   title=dom-canvas-toDataURL><a href="#todataurl">toDataURL()</a></code>
+   method) must be rendered with no color correction.
+
+  <p class=note>Thus, in the 2D context, calling the <code
+   title=dom-context-2d-drawImage><a href="#drawimage">drawImage()</a></code>
+   method to render the output of the <code title=dom-canvas-toDataURL><a
+   href="#todataurl">toDataURL()</a></code> method to the canvas, given the
+   appropriate dimensions, has no visible effect.
+
   <h5 id=security1><span class=secno>3.14.11.3. </span>Security with <code><a
    href="#canvas">canvas</a></code> elements</h5>
 

diff --git a/source b/source
@@ -15282,7 +15282,7 @@ notes on what would need to be defined for dashed lines:
 
   // support methods
   function FillPlasma(data, color) { ... }
-  function AddCload(data, x, y) { ... }
+  function AddCloud(data, x, y) { ... }
 </pre>
 
   </div>
@@ -15411,26 +15411,44 @@ notes on what would need to be defined for dashed lines:
 
   <p>The <code>canvas</code> APIs must perform colour correction at
   only two points: when rendering images with their own gamma
-  correction information onto the canvas, to convert the image to the
-  color space used by the canvas (e.g. using the <code
-  title="dom-context-2d-drawImage">drawImage()</code> method with an
-  <code>HTMLImageElement</code> object), and when rendering the actual
-  canvas bitmap to the output device.</p>
-
-  <p>Thus, in the 2D context, colors used to draw shapes onto the
-  canvas will exactly match colors obtained through the <code
+  correction and color space information onto the canvas, to convert
+  the image to the color space used by the canvas (e.g. using the
+  <code title="dom-context-2d-drawImage">drawImage()</code> method
+  with an <code>HTMLImageElement</code> object), and when rendering
+  the actual canvas bitmap to the output device.</p>
+
+  <p class="note">Thus, in the 2D context, colors used to draw shapes
+  onto the canvas will exactly match colors obtained through the <code
   title="dom-context-2d-getImageData">getImageData()</code>
   method.</p>
 
   <p>The <code title="dom-canvas-toDataURL">toDataURL()</code> method
   must not include color space information in the resource
-  returned.</p>
+  returned. Where the output format allows it, the color of pixels in
+  resources created by <code
+  title="dom-canvas-toDataURL">toDataURL()</code> must match those
+  returned by the code
+  title="dom-context-2d-getImageData">getImageData()</code>
+  method.</p>
 
   <p>In user agents that support CSS, the color space used by a
   <code>canvas</code> element must match the color space used for
   processing any colors for that element in CSS.</p>
 
-
+  <p>The gamma correction and color space information of images must
+  be handled in such a way that an image rendered directly using an
+  <code>img</code> element would use the same colors as one painted on
+  a <code>canvas</code> element that is then itself
+  rendered. Furthermore, the rendering of images that have no color
+  correction information (such as those returned by the <code
+  title="dom-canvas-toDataURL">toDataURL()</code> method) must be
+  rendered with no color correction.</p>
+
+  <p class="note">Thus, in the 2D context, calling the <code
+  title="dom-context-2d-drawImage">drawImage()</code> method to render
+  the output of the <code
+  title="dom-canvas-toDataURL">toDataURL()</code> method to the
+  canvas, given the appropriate dimensions, has no visible effect.</p>
 
 
   <h5>Security with <code>canvas</code> elements</h5>