Preserving Black color values exporting pages to i
Printed From: Debenu Quick PDF Library - PDF SDK Community Forum
Category: For Users of the Library
Forum Name: I need help - I can help
Forum Description: Problems and solutions while programming with the Debenu Quick PDF Library and Debenu PDF Viewer SDK
URL: http://www.quickpdf.org/forum/forum_posts.asp?TID=3095
Printed Date: 29 Apr 24 at 2:15AM
Software Version: Web Wiz Forums 11.01 - http://www.webwizforums.com
Topic: Preserving Black color values exporting pages to i
Posted By: MarcoAbbate
Subject: Preserving Black color values exporting pages to i
Date Posted: 26 Mar 15 at 3:20PM
Dear All,
I have a PDF file containig CMYK images.
On these images there is some black text.
Using Acrobat PRO the value of the black thext is C=0,M=0,Y=0, K=100.
When I export the page to image, in JPEG, TIFF or PNG format, and then import the image into a new PDF file, the color values of the back text changes, and the black color is "spread" on the other channels, CMY, too.
I tried to convert the exported images using Acrobat function "Create PDF from File", with the same results: the text is not only K anymore, but has CMY values, too.
What I need is that when I export the PDF page as image, the result image has the same color value of the PDF page, especially for the Black.
It seems the export function convert in some way the colors, mostly the black values.
Is there any function able to preserve the K values, or making something similar to the "black compensation", in order to avoid this problem?
Looking forward to your reply,
Best Regards,
Marco Abbate.
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Replies:
Posted By: andrewkowa
Date Posted: 31 Mar 15 at 1:53AM
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I have a same problem with trasparency, I cannot use the printer because there are points of black/white in the pages. So should I use poor quality services? like http://www.overnightprints.co.uk/stamps" rel="nofollow - http://www.overnightprints.co.uk/stamps or other?
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Posted By: Ingo
Date Posted: 31 Mar 15 at 7:22AM
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Hi Andrew, we can't look over your shoulder on your Screen ;-) It's not much you've written to describe your problem. With more details and relevant code snippets perhaps somebody can help ;-) Cheers and welcome here, Ingo
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Cheers,
Ingo
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Posted By: erico
Date Posted: 07 Apr 15 at 6:55PM
Perhaps the act of outputting the items causes default color values to be used. I had similar issues a while back with text color. What is important to remember is that every time the current page is changed, you must reselect your default color. I was only dealing with text, so SetTextColorCMYK(0,0,0,1) was enough for me. You may need to update several color related items.
Perhaps you have a need I do not understand, but why create image files
at all? Use ExtractFilePages() or ExtractFilePagesEx() and create the
second PDF directly, bypassing the intermediate step. I would expect this to
preserve the K.
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Eric O
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