For reasons that I will neglect to tell you, what are the sizes of the image areas in GM?
Mist
310x314 for a card with a graphics area and text area.
625x314 for a card with graphics and buttons.
625x374 for a card with just a graphics area.
If you put your cursor in the bottom right corner, it will display different numbers because the coordinates actually start 5 pixels too far to the top left.