
Thread
2006.03.29 16:33 "Re: [Tiff] extracting TIFF image from PDF and decompressingwith Libtiff", by Gerben Vos
At 04:29 PM 3/28/2006, Philip Watkinson wrote:
I have a PDF file that contains a TIFF image.
Leonard Rosenthol wrote:
PDF files do NOT contain TIFF images. They may contain image data that at one time in the past was a TIFF - but by the time it is processed into a PDF, it is no longer valid TIFF data. Hence, libtiff fails.
Indeed. What you have saved to the file is probably the raw LZW- compressed image data. What you can do is construct a TIFF *around* that, if you also read the size, colour space, etc. from the PDF.
For the most common ways to encode and compress images, there is a remarkable correspondence between the way TIFF and PDF encode them, so lossless conversion is often possible. But it isn't true that you can simply embed a TIFF in a PDF, nor the reverse.
Gerben Vos.