Struggling with values needed to make a selection.

[marcel_911]

Hi, I am new to photoshop CS4 javascript scripting. (I am using a Mac but I don't think that makes any difference here)

I am trying to write a simple script to take a single input image and then split it into three and save it.

I haven't got very far yet. While I am practicing I am just creating a new document rather than loading one in.

I have set my ruler units to CM and created a new document of 80cm x 60cm at 180dpi and made a new art layer. This is working fine.

I want to make a selection for example of 20cm x 20cm starting from the top left corner.

I tried the obvious

activeDocument.selection.select([[0,0], [20,0], [20,20], [0,20]], SelectionType.REPLACE)

All I get is a tiny selection in the top left, but nothing like 20cm x 20cm.

I read in the manual about Unit Values but couldn't work out what they were talking about.

If I have my ruler set to CM why is the selection not being made in CM?

It seems to be PIXELS regardless of unit type.

Am I supposed to work out 20cm into Pixels myself?

Thanks