Hello,
The XHTML-Print specification states how an enhanced layout printer should
handle EXIF markers in JPEG images
(http://www.pwg.org/xhtml-print/HTML-Version/XHTML-Print.html#a_jpeg.3).
A JPEG decoder for an XHTML-Print implementation which
supports the Enhanced Layout Extension shall decode the
TIFF IFDs embedded in the EXIF APP1 and APP2 markers, as
described in Section 2.6.4 of [JEIDA]. The following IFDs
shall be fully supported (i.e. they shall not be ignored).
Tag Name: Image Orientation
Field Name: Orientation
Description: Sets image orientation in 90-degree increments,
and enables transposition.
This requirement was discussed at the April and June 2002 meetings. See
http://www.pwg.org/xhtml-print/minutes/Minutes-June-24-2002.html and
http://www.pwg.org/xhtml-print/minutes/Minutes-April-17-2002.txt The June
meeting decide to make the processing of EXIF markers optional. Therefore,
text above should be changed to say "may decode" from "shall decode" and
"shall be fully supported (i.e., shall not be ignored)." becomes "may be
supported."
A JPEG decoder for an XHTML-Print implementation which
supports the Enhanced Layout Extension may decode the
TIFF IFDs embedded in the EXIF APP1 and APP2 markers, as
described in Section 2.6.4 of [JEIDA]. The following IFDs
may be supported.
Tag Name: Image Orientation
Field Name: Orientation
Description: Sets image orientation in 90-degree increments,
and enables transposition.
Melinda Grant posed a question in the June meeting about optional support
for EXIF markers and a future CSS property that specified image orientation
and how the two would interact. The CSS working group of the W3C is
currently considering an image orientation property, so this concern could
come up in one to two years.
I propose that a CSS property, if present, take precedence over the image's
EXIF orientation markers.
Comments?
Jim Bigelow,
Editor: XHTML-Print & CSS Print Profile
IEEE, Printer Working Group
http://www.pwg.org/xhtml-print
Hewlett-Packard
208-396-2068
jim.bigelow at hp.com