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Topic: Re: JPEG image
Conf: (P-PDF) Developers, Msg: 57607
Date: 5/29/2002 05:26 PM
Thanks for your valuable info....
Using DCTDecode filter it works fine replacing a JPEG file in a PDF with
colorspace set to RGB. How do I replace an image in a PDF file that has
colorspace set to DeviceCMYK? ( The image seems to be distorted)
----- Original Message -----
From: "p-pdf-developer Listmanager"
Sent: Wednesday, July 11, 2001 3:09 PM
Subject: JPEG image
> From: "Aandi"
> --- Planet PDF Forum | http://forum.planetpdf.com ----
> If you are compressing images with Flate you must completely decompress
them, process all headers, and extract the pixels alone. This requires full
familiarity with the image format.
> However, for JPEG files there is a shortcut. In most cases the entire JPEG
file including all headers is valid as input to the DCTDecode filter. So
there is no need to change the file, only analyse it to extract width,
height and colour space information.
> For every other image format you must extract the image pixels; in a very
few cases (e.g. TIFF G4 single strip files) you can use the compressed data
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