User Manual - pancroma

When the transformed image becomes visible you will be able to mark it usingyou cursor. The top menu allows you to select your pen width and select yourmasking shapes. Using your cursor, mark out any frequencies that you want toremove from your image. For example, if we wished to remove all highfrequencies from the image, we would retain the center of the transformed imageand remove the outside frequencies (low frequencies are in the middle).The idea behind the mask tools is to remove frequencies from the image. Anyfrequency covered by red will be eliminated from the reverse transform back tothe image, that is, both the real and imaginary components of the transformedimage will be zeroed.In order to use the mask shapes, click on the upper left and lower right corners,then choose the menu item. (This applies to all shapes: rectangle, closed circle(ellipse), open circle). When you are done defining your filter select ‘Exit’ fromthe menu. The designated frequencies will be removed from the transform andthe result will be inverse transformed back to the spatial domain. The result ofthis example is shown below.IMPORTANT NOTE: Because of the RAM constraints, no ‘Undo’ function isavailable. If you decide that you do not like your mask, you will have to startover.289