These are image operations where the input is an image, and the output is an image, e.g. image enhancement. The operations can be linear, such as Gaussian smoothing, or non-linear, such as morphology.
Selecting an operation from the Image Processing menu performs that operation on the current active pane. The result of the operation is an image which is placed at the end of the stack of images.
Load an image (the basement ones are good for the following).
Try any operation under ``Image-processing''. Note that these operations are actually creating a new image that can be further processed. This new image may be saved to disk using the File menu item.
To get back to the original image, use PageUp and PageDown. If images appear to look completely black, they may just be very dark.
From the original image, select Display and select the image corresponding to the latest image processing. Holding down the left mouse button on the image will now superimpose the results of the operation on a small portion of the original image. To switch of the enhance lens select Display again.