W3C home > Mailing lists > Public > public-css-commits@w3.org > February 2012

csswg/css3-images Overview.html,1.289,1.290 Overview.src.html,1.299,1.300

From: Tab Atkins Jr.. via cvs-syncmail <cvsmail@w3.org>
Date: Fri, 17 Feb 2012 23:17:55 +0000
To: public-css-commits@w3.org
Message-Id: <E1RyX3r-0000v6-92@lionel-hutz.w3.org>
Update of /sources/public/csswg/css3-images
In directory hutz:/tmp/cvs-serv3522

Modified Files:
	Overview.html Overview.src.html 
Log Message:
Rewrite the intro to image-orientation to be clearer about data-based orientation versus metadata-based orientation.

Index: Overview.html
===================================================================
RCS file: /sources/public/csswg/css3-images/Overview.html,v
retrieving revision 1.289
retrieving revision 1.290
diff -u -d -r1.289 -r1.290
--- Overview.html	17 Feb 2012 23:05:16 -0000	1.289
+++ Overview.html	17 Feb 2012 23:17:52 -0000	1.290
@@ -2283,17 +2283,20 @@
    on the Page: the &lsquo;<a href="#image-orientation0"><code
    class=property>image-orientation</code></a>&rsquo; property</h3>
 
-  <p>Sometimes images from camera phones, digital cameras or scanners are
-   encoded sideways. For example, the first row of image data can represent
-   the leftmost or rightmost column of image pixels. Furthermore, often such
-   devices have limited resources, and do not have the capability to rotate
-   the image into an upright orientation. However, this type of device may
-   have internal knowledge or can accept input from its user as to the
-   rotational correction to perform. The &lsquo;<a
+  <p>If a picture is taken with a camera turned on its side, or a document
+   isn't positioned correctly within a scanner, the resultant image may be
+   "sideways" or even upside-down. The &lsquo;<a
    href="#image-orientation0"><code
    class=property>image-orientation</code></a>&rsquo; property provides a way
-   to apply an &rdquo;out-of-band&ldquo; rotation to image source data to
-   correctly orient an image.
+   to apply an "out-of-band" rotation to image soruce data to correctly
+   orient an image.
+
+  <p class=note>Note that some devices will "tag" an image with some metadata
+   indicating its correct orientation, so image viewing software can do the
+   necessary transformation themselves. Due to legacy compatibility
+   restraints, browsers are required to ignore this data by default. A future
+   level of this specification is expected to have a value that applies the
+   metadata-specified transformation automatically.
 
   <p class=note>Note this facility is not intended to specify layout
    transformations such as arbitrary rotation or flipping the image in the
@@ -2370,10 +2373,6 @@
    &lsquo;<code class=css>image()</code>&rsquo; function with an opposite
    directionality to its context, or using CSS Transforms.
 
-  <p class=note>Note that in CSS, orientation data encoded in the image (e.g.
-   EXIF data) is ignored. <span class=issue>Is this an issue? What do
-   printers do?</span>
-
   <div class=example>
    <p>The following example rotates the image 90 degrees clockwise:</p>
 

Index: Overview.src.html
===================================================================
RCS file: /sources/public/csswg/css3-images/Overview.src.html,v
retrieving revision 1.299
retrieving revision 1.300
diff -u -d -r1.299 -r1.300
--- Overview.src.html	17 Feb 2012 23:05:16 -0000	1.299
+++ Overview.src.html	17 Feb 2012 23:17:53 -0000	1.300
@@ -1489,24 +1489,12 @@
 <h3 id="image-orientation">
 Orienting an Image on the Page: the 'image-orientation' property</h3>
 
-	<p>Sometimes images from camera phones, digital cameras or scanners are
-	encoded sideways.
-	For example, the first row of image data can represent the leftmost or
-	rightmost column of image pixels. Furthermore, often such devices have limited
-	resources, and do not have the capability to rotate the image into an upright
-	orientation. However, this type of device may have internal knowledge or can
-	accept input from its user as to the rotational correction to perform.
-	The 'image-orientation' property provides a way to apply an
-	&rdquo;out-of-band&ldquo; rotation to image source data to correctly orient
-	an image.
+	<p>If a picture is taken with a camera turned on its side, or a document isn't positioned correctly within a scanner, the resultant image may be "sideways" or even upside-down.  The 'image-orientation' property provides a way to apply an "out-of-band" rotation to image soruce data to correctly orient an image.</p>
 
-	<p class="note">Note this facility is not intended to specify layout
-	transformations such as arbitrary rotation or flipping the image in the
-	horizontal or vertical direction. (See [[CSS3-2D-TRANSFORMS]] for a feature
-	designed to do that.)
-	It is also not needed to correctly orient an image when printing in landscape
-	versus portrait orientation, as that rotation is done as part of layout.
-	(See [[CSS3PAGE]].)
+	<p class='note'>Note that some devices will "tag" an image with some metadata indicating its correct orientation, so image viewing software can do the necessary transformation themselves.  Due to legacy compatibility restraints, browsers are required to ignore this data by default.  A future level of this specification is expected to have a value that applies the metadata-specified transformation automatically.</p>
+
+	<p class="note">Note this facility is not intended to specify layout transformations such as arbitrary rotation or flipping the image in the horizontal or vertical direction. (See [[CSS3-2D-TRANSFORMS]] for a feature designed to do that.)
+	It is also not needed to correctly orient an image when printing in landscape versus portrait orientation, as that rotation is done as part of layout. (See [[CSS3PAGE]].)
 	It should only be used to correct incorrectly-oriented images.</p>
 
 	<table class="propdef">
@@ -1556,10 +1544,6 @@
 
 	<p>The 'image-orientation' property must be applied before any other transformations, such as being specified in the ''image()'' function with an opposite directionality to its context, or using CSS Transforms.</p>
 
-	<p class="note">Note that in CSS, orientation data encoded in the image
-	(e.g. EXIF data) is ignored. <span class="issue">Is this an issue? What
-	do printers do?</span>
-
 	<div class="example">
 		<p>The following example rotates the image 90 degrees clockwise:</p>
 
Received on Friday, 17 February 2012 23:17:56 UTC

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