The position of an image may be absolute on the screen or relative to the coordinate system (see properties of the image, 3.1.1). The latter is achieved by specifying up to three corner points. This gives you the flexibility to scale, rotate and even distort images.
Lets create three points A, B and C to explore the effects of the corner points. Set A as the first and B as the second corner of your image. By dragging A and B in Move mode you can explore their influence very easily. Now set A as the first and C as the fourth corner. Finally, you could set all three corner points and see how you dragging the points distorts your image.
You already saw how to influence the position and size of your image. If you want to attach your image to a point A and set its width to 3 and its height to 4 units, you could do the following:
When you drag point A in Move mode now, your image keeps the desired size.
See command Corner (4.3.13).
You may set an image to be in the background (properties of the image, 3.1.1). A background image lies behind the coordinate axes and cannot be selected with the mouse any more.
In order to change the background setting of an image, choose Properties from the Edit menu.
An image can be made transparent in order to see images or axes lying behind it. You can set the transparency of an image by specifying a filling value between 0% and 100% (properties of the image, 3.1.1).