We're using the compare utility intensively and it works flawlessly. If a certain pixel in image A is different from the corresponding pixel in image B, the resulting pixel in image C will be overlayed with 90% magenta.
Now, we're wondering, if it is possible to consider a certain threshold value in order to neglect slight differences.
Example:
- Image A and B are in CMYK colorspace
- Pixel (x,y) of image A is C100, M100, Y100, K100
- Pixel (x,y) of image B is C101, M100, Y100, K99
With a comparison threshold value of 1 you could define that a tolerance of +/- 1 for each color value is allowed. In this case image C would have a 90% white-overlayed pixel at this position.
Background of this question:
We have experienced slight color differences when having either the PowerPC or the Intel Mac architecture while using Adobe InDesign CS3 resp. QuarkXPress 7 and working with transparencies. Such problems can be reproduced, meaning that you have a document with transparencies in InDesign and create a PDF document using a PowerPC and then using an IntelMac. When you then compare these PDF documents, you will recognize magenta-colored pixels. Moreover, this is not a problem of the RIP (e.g. Ghostscript, Photoshop). You can prove that this problem already exists in the PDF document.
In addition to that I a sure that such comparison threshold value would be nice, since these color differences can only be measured but not be seen.
Thanks in advance for any feedback.
Kind regards,
Sven