2013.04.28 06:37 "Re: [Tiff] Problem with TIFFReadEndcodeStrip()", by Steve McKinney

BTW, using libtiff 4.0.1.

Steve

-----Original Message-----
From: Bob Friesenhahn [mailto:bfriesen@simple.dallas.tx.us]
Sent: Saturday, April 27, 2013 6:22 PM
To: Steve McKinney
Cc: tiff@lists.maptools.org
Subject: Re: [Tiff] Problem with TIFFReadEndcodeStrip()

On Sat, 27 Apr 2013, Steve McKinney wrote:
>
> I?ve been just about tearing my hair out trying to track down the
> cause of an access violation when attempting to read a JPEG compressed
> TIFF using TIFFReadEncodedStrip().  After some research and fiddling I
> found I was able to work around the problem by setting
TIFFTAG_JPEGCOLORMODE to JPEGCOLORMODE_RGB before beginning to read the
TIFF.  All well and good, but *why* do I have to do this?  And should
libtiff really crash if I don?t?

The JPEG is likely in YCbCr format and may be subsampled as well.
Setting TIFFTAG_JPEGCOLORMODE to JPEGCOLORMODE_RGB causes libjpeg to return
RGB pixels instead.

You did not provide enough information for me to say any more.

Bob
--
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/