Action Perspective by defining four target corners

Summary:

How can a perspective transformation be realized by defining the coordinates of four target corners

Action Perspective by defining four target corners

chrili 10 Nov 2008 20:39

Hi everyone and first of all: thanks for providing this great software!

This is my problem: I would like to use phatch to fit several screenshots into a given photograph of a computer monitor in "natural" 3D-perspective. "Watermark" and "Perspective" seem to be suitable for this task.
As I do not completely understand the input parameters of "Action Perspective", especially the exact meaning of "Bottom/Right Shear Factor", this kind of transformation is a process of trial and (even more) error for me. I also know about the PIL "Image.transform PERSPECTIVE option", but also I do not understand the meaning of the eight parameters there (and also was not able to find detailed information about it …).

For my purpose it would be perfect to give the coordinates of four target corners as parameteres for the perspective transformation - just as it is implemented in gimp. Does anyone have a hint for me?

Thanks in advance!
—
Christoph

Re: Action Perspective by defining four target corners

stani 18 Nov 2008 15:50

If you find how to do this let me know. I've tried already to simplify PIL with the shear factors.