Imported Image Resolution
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=3094
Printed Date: 28 Apr 24 at 12:10PM
Software Version: Web Wiz Forums 11.01 - http://www.webwizforums.com
Topic: Imported Image Resolution
Posted By: MarcoAbbate
Subject: Imported Image Resolution
Date Posted: 24 Mar 15 at 9:15AM
Hi everybody!
I'm facing a strange behaviour importing images using the function "DrawImage".
I have a JPEG image with a resolution on 150DPI.
Its dimensions are 404x275 mm.
When I import the image, the PDF page has the dimensions of 841.7x573.3 mm.
After some tests I found the dimensions of the PDF page are equal to the image dimesions IF THE IMAGE WAS AT 72DPI...
I tried to set the correct dimensions as follows, even if some functions are redundant:
int pW=QP.ImageWidth();
int pH= QP.ImageHeight();
QP.SetPageDimensions(pW ,pH);
QP.SetImageResolution(150, 150, 2);
QP.FitImage(0, 0, pW, pH, 0, 0, 0);
QP.SetOrigin(1);
i = QP.DrawImage(0, 0, pW, pH);
i = QP.SaveToFile(filePDF);
But I always get the same wrong dimensions (841.7x573.3 mm) in the output.
I tried to import JPEG, TIFF and BMP image, always with the same wrong result.
Note the images by themselves are correct, with the right ( 404x275 mm).
Do you have any hint or solution about this issue?
Thank you very much in advance!
Marco.
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Replies:
Posted By: MarcoAbbate
Date Posted: 25 Mar 15 at 11:41AM
SOLUTION FOUND !!!
The problem is due to the fact that in any case the imported image is managed as it would have a resolution of 72 DPI.
In this case the PDF page takes its dimensions according to this wrong assumption.
To solve the problem it is mecessary to apply a scale factor from the default wrong 72 DPI resolution to the right one:
Note DPIres is the real image resolution...
double ImageWidthInPoints = (double)QP.ImageWidth() / dpix * DPIres;
double ImageHeightInPoints = (double)QP.ImageHeight() / dpiy * DPIres;
int pW=QP.ImageWidth();
int pH= QP.ImageHeight();
QP.SetOrigin(1);
i = QP.DrawImage(0, 0, pW, pH);
float stdRes = 72;
float PageScale = stdRes / DPIres;
QP.SetPageDimensions((pW * PageScale), (pH * PageScale));
QP.FitImage(0, 0, (pW * PageScale), (pH * PageScale), 0, 0, 0);
i = QP.SaveToFile(filePDF);
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