LibTiff Mailing List
TIFF and LibTiff Mailing List Archive
October 2005
Previous Thread
Next Thread
Previous by Thread
Next by Thread
Previous by Date
Next by Date
Contact
The TIFF Mailing List Homepage
This list is run by Frank Warmerdam
Archive maintained by AWare Systems
Thread
2005.10.28 03:42 "Re: How located pixels with BitsPerSample not bound to byte?", by Frank Warmerdam
On 10/27/05, David McKenzie wrote: > It so happens that while testing a viewer application I'm working on, two > problems were tracked to this section of GDAL code (in geotiff.cpp). The > first is apparently a simple coding error. Notice that the local variable > iPixelBitSkip in the code excerpt is initialized but never used. I saw this > first in a separate section that handles 12-bit samples as a special case. > There I fixed the problem by simply replacing the statement "iBitOffset += > 12" with "iBitOffset += iPixelBitSkip". In the section here that handles > other 1-32 bit samples a similar fix is necessary. I haven't tried the very > latest version of OpenEV, but I believe for the above reason it can't > correctly display many of Bob Friesenhahn's example TIFFs (see below) with > "contig" in the name. David, Yikes! And here I thought I had tested comprehensively with Bob's images. I must have been out of it that day. I have fixed this and now all the contig rgb images work fine in OpenEV. Note there is the fix for incrementing iBitOffset, and a fix to the computation of nBitsPerLine. The updated code is available at: http://www.gdal.org/srctree/frmts/geotiff.cpp > The second problem involves this same section of code (1-32 bit sample... I'll stay out of this issue, though I suspect that 24bit data should not be byte swapped. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, warmerdam@pobox.com light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent