- 1997.05.02 09:17 "Re: BIG TIFF file problems", by Bjorn Brox
- 1997.05.02 09:47 "RE: BIG TIFF file problems", by Caspar Evans
- 1997.05.02 14:32 "RE: BIG TIFF file problems", by Ed Grissom
- 1997.05.02 16:41 "RE: BIG TIFF file problems", by Brian McDougle
- 1997.05.05 10:04 "RE: BIG TIFF file problems", by Gerben Vos
1997.05.02 09:17 "Re: BIG TIFF file problems", by Bjorn Brox
I am having problems with very large tiff files created by our RIP software.
The tiff file created is a bilevel tiff comprising of uncompressed data in a single strip!! The size of the file is 707,953,939 bytes.
WOW!
# tiffcp -s -c lzw a1.tif a1c.tif
a1.tif: Warning, incorrect count for field "StripOffsets" (1, expecting
111); tag ignored.
This error message is correct, see below:
I have a theory as to why this is happening:
Looking at a tiffdump of the file:
# tiffdump a1.tif
ImageWidth (256) LONG (4) 1<85640>
ImageLength (257) LONG (4) 1<66133>
StripOffsets (273) LONG (4) 1<174>
RowsPerStrip (278) SHORT (3) 1<597>
StripByteCounts (279) LONG (4) 1<707953765>
I noticed that the width (85640) multiplied by the height (66133) (=5,663,630,120) exceeds the maximum possible value of the type uint32 which is 4,294,967,295. It is this 'overflow' that causes tiffcp to fail!
The file tells: RowsPerStrip 597.
This means that there have to be (ImageLength + ImageLength - 1)/RowsPerStrip StripOffset and StripByteCounts values too, i.e. 111.
I am wondering if anyone agrees with my theory.
Well, you migth also get these kinds of errors, but by dividing the file into strips this error can be avoided.
--
Bjorn Brox, mailto:brox@corena.no, CORENA A/S, http://www.corena.no/
P.O.Box 1024, Kongsberg Naeringspark, N-3601 Kongsberg, NORWAY
Phone: +47 32 73 74 35, Fax: +47 32 73 68 77, Mobile: +47 92 63 85 90