Cropping invisible images

[jbv at souslelogo.com]

Thank you for your replies.
One more question : what happens to the imagedata
when an image is resized ?
For instance :
    put width of img 1 into w
    put height of img 1 into h
    put w/h into tratio
    set width of img 1 to 150
    set height of img 1 to 150/tratio

And then when you crop the image...
I am trying to figure out where my problems come from.

Best,
jbv