HOW TO: Compare Images in Multiple Ways

Image comparison can be performed in a variety of methods using the v20 LEADTOOLS .NET SDK. Below is a list of the methods used within the following project:

• (CompareXOR method) Combining the images via XOR: CombineCommand (using the OperationXor flag)
  
• (CompareIntensities method) Comparing the average image intensities: StatisticsInformationCommand
  
• (CompareHSV method) Compare the average hue and saturation intensities: ColorSeparateCommand
  
• (CompareFourier method) Compare the color frequencies: FastFourierTransformCommand (using the PadOptimally flag to support non-standard [meaning powers of two] image sizes)
  
  • Note: This command supports providing the frequency table as a pointer (via DataPointer), in addition to the managed array (Data). To see this demonstrated within the C# project below, you simply need to enable the unsafe compiler flag and add a pre-processor symbol for "UNSAFE_FOURIER".

The full project (originally based on one of our old 25x25 blog posts: Compare Images) is available in both C# and VB.NET:

• C#:
  File Attachment(s):

  ImageCompare_CSharp.zip (853kb) downloaded 113 time(s).
• VB.NET:
  File Attachment(s):

  ImageCompare_VBNet.zip (853kb) downloaded 167 time(s).