Aligning image content
You can compare images that have been resized, rotated, reflected, or cropped.
Click Autoscale 
to automatically enlarge the smaller image to match the scale of the larger one.
Click Rotate Clockwise 
or Rotate Counterclockwise 
to rotate the current image ninety degrees to the right or to the left.
Click Flip Horizontally 
or Flip Vertically 
to reflect the current image across its y-axis or x-axis.
If one image is a cropped version of the other, you can drag the mouse over the difference pane to adjust the position of the right image's top-left corner. To reset the offset to (0,0) choose Reset Difference Offset or simply click the offset label. For finer control, use the arrow keys to nudge the offset one pixel at a time, or press Ctrl+arrow keys to move by a larger amount. Note that the difference pane must be selected for the keyboard nudge function to work.
Tolerance Mode
Select Tolerance Mode 
to have difference pixels indicate matches, unimportant differences, and important differences. It uses a configurable Tolerance to define the greatest degree of difference that is considered unimportant. You can also define Replacements to ignore specific color changes between images. By default, shades of gray are used for matches, shades of blue are used for unimportant differences, and shades of red are used for important differences. You can adjust these colors to suit your preferences. (See Picture Compare Colors.)
Select Ignore Unimportant Differences 
to ignore any differences less than or equal to the tolerance. They will be handled the same as matching pixels.
Mismatch Range Mode
Select Mismatch Range Mode 
to have difference pixels represent the degree of difference between the images. Black pixels are used for matches and yellow pixels are used for differences. Brightness represents the degree of difference.
Blend Mode
Select Blend Mode 
to use a configurable Blend percentage to combine the images. Decrease the percentage to make the right image more dominant.
