Canvas Clear - Clears the portion of a Loaded image

Hello Guys,

I am using a canvas which has an image loaded. I creates a rectangle over specific cordinates on the canvas to depict part of the image.

Now, when i close the panel, I clear the canvas rectange using :- 

CanvasClear (AttributePanelHandle, ATTR_PANEL_CANVAS, MakeRect (TOP,LEFT,HEIGHT,WIDTH));

I make this so that when I open it again I do not see previous rectangle marking.

Now the problem comes is that when I reopen my panel the rectangle is gone, but the loaded part of the image is also erased as can e seen in the below picture. How can I hoild back the loaded picture. Is there any alternative to canvas clear to remove the rectange.

                               BEFORE                                                             AFTER

Thanks

Raunak