How to convert PDF positions in points into Jpeg positions in pixels ?
Posted on 2009-05-05
let me explain by an example:
1) We have a PDF page which dimensions is 500,9 pt WIDTH by 715,6 pt HEIGHT
I have a lot of 'words' which i know the exact position in points (X,Y couple) within this page.
2) The target image is a JPEG which dimensions is 420 pixels WIDTH by 600 pixels HEIGHT.
This image ha been calculated from the PDF page, and is in 150dpi (I am not sure it matters).
3) I need to position correctly the words in the target JPEG image.
So I need to convert the (X,Y couple in points from the PDF) to the equivalent (X,Y couple in pixels in the JPEG image).
I know that the HEIGHT in the PDF is calculated from the bottom of the page.
If anyone has a magic formula, or explanations of how I should process to correctly position the 'words' in the target Jpeg, I would greatly appreciate.
Thanks in advance for your detailed answers