Victor Image Processing Library How-to Tips

Comparator Sample Application

Comparator is an application that demonstrates the Victor Library multiimage functions. With this app you can combine, compare, and analyze images. The screen above demonstrates image analysis and comparison.

Image analysis
The Operator image is being compared to the Source image. The statical measure of similarity is the correlation coefficient. A value of 1.00 would mean the images are identical. In this case a value of 0.72 indicates a difference between the two images, that is, something has changed.

Image comparison
The Operator image is compared to the Source image and the Result image is composed of the difference. The vehicle in the foreground is immediately obvious.


Many of the functions in the Victor Library allow multiple images to be compared, combined, or analyzed. These techniques can be used for

  • motion detection,
  • finding alignment or registration marks,
  • pattern matching, and
  • special effects.

These important functions can be arranged in three catagories:

Combining images   Comparing images   Analyzing images
addimage
addtexture
andimage
bleach
cover
coverclear
divideimage
isolate
multiplyimage
multiplynegative
orimage
wtaverage
correlateimages
darker
difference
differenceabs
lighter
subimage
xorimage
calcavglevel
correlationcoef
calchisto
pixelcount
sortpixelsbyval

The application, Comparator, contains all these Victor Library functions so they can be tested with any images. Download VB Comparator and source code (96 Kb) or C# Comparator and source code (120 Kb). Requires the Victor Library v 5.6 commercial release or eval version.


Victor Image Processing Library

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