Image Comparer Online Help

  IMAGE COMPARER

Highlight Image Differences

To see highlighted differences between images, go to the Image Pair tab. Between the two preview images, you will see a small box with the words "Highlight differences". If there is not a check mark in the box, click on the box, and a check mark will appear. (A second click will remove the check mark.)

When there is check mark in the "Highlight differences" checkbox, you will see small rectangles on the some of the preview images. These rectangles highlight areas of the images that Image Comparer considers to be different.

Two points to keep in mind:
-- No difference highlights will appear on image previews with 100% similarity.
-- The differences can be anywhere in a highlighting rectangle, not necessarily at the center.

Right below the "Highlight differences" checkbox is the "Change differences threshold" control. (The name of the control appears when you hold the mouse cursor over the control.) When the slider on this control is all the way to the right, any rectangles you see contain what Image Comparer considers to be major differences between the images. As you move the slider to the left, additional highlighting rectangles will appear. The further left you must move the slider to make a rectangle appear, the smaller the difference found in the rectangle.

Three more points to keep in mind:
-- For images without major differences, no highlighting rectangles will appear until the slider is some distance to the left.
-- For some images, there might be a point where moving the slider further to the left will not cause additonal rectangles to appear. (At that point, all differences identified by Image Comparer have been highlighted.)
-- As you select different image pairs, the slider in the "Change difference threshold" will change position. Image Comparer automatically positions the slider so that you will have a moderate number of highlights on the previews. Usually, moving the slider to the right from the position selected by Image Comparer will reduce the number of highlighting rectangles, while moving the slider to the left from the position selected by Image Comparer will cause additional rectangles to appear.