Picture Compare Overview

 PreviousUpNext

A Picture Compare session compares a pair of image files visually, showing the differences between them.

pixcompare1.zoom33

Aligning Image Content

You can compare images that have been resized or cropped.

Select View > Stretch to Same Size PixStretch to automatically enlarge the smaller image before comparison.

If one image is a cropped version of the other, you can drag the mouse over the difference panel to offset one image in relation to the other.  To reset the offset back to (0,0) select View > Reset Difference Offset or simply click on the offset display at the bottom of the difference panel.

For finer control, use the arrow buttons to nudge the offset one pixel at a time, or Ctrl+arrow buttons to move by a larger amount.  Note that the center difference panel must be selected for the keyboard nudge function to work.

Hide Center Panel

Select View > Hide Difference Panel PixCompareNone to suppress the difference panel.  The overall result of a pixel-by-pixel comparison is shown in the lower-left corner of the window.

Tolerance Mode

Select View > Tolerance Mode PixCompareTolerance to identify parts of the image that are more different than the tolerance setting, and those that are less different.

By default, the differences panel uses black for matching pixels, red for differences greater than the tolerance, and blue for differences less than the tolerance.  You can change the colors to suit your preference.  (See Picture Compare Options.)

Notice that this mode does not show you the quantitative degree of difference, but merely whether or not it exceeds the threshold set by Tolerance.

Enable View > Ignore Unimportant Differences InsigIgnored to ignore any differences less than or equal to Tolerance.  They will be handled the same as identical pixels.

Mismatch Range Mode

Select View > Mismatch Range Mode PixCompareRange to show the degree of difference between the images.  Various shades of yellow are used in the differences panel to highlight differences: the brighter the color, the greater the difference.  Black is used for identical pixels.

Binary Operation Mode

Select View > Binary Operation Mode PixCompareBinaryOp to display in the difference panel an image created by applying a boolean operation on the RGB (red/green/blue) values of each pixel.