Correlation: template matching

Building the Cantata Workspace

1. Convert the input image $DIP/data/gull.viff to floating point using the operator Convert Type.
2. Select a small (10x10) pattern from the image using the Extract operator.
3. Perform the correlation between the image and the pattern using the Linear Operator. See Statistics operator to find the coordinates of the maximum point of the result
4. Perform the normalized correlation:
   • Take the square of the gull image using the Square operator.
   • Create a constant kernel with same size as the pattern (10x10) using the Constant operator and perform correlation between the squared image and this kernel.
   • Take the square root of the result using the Square Root operator.
   • Divide the normal correlation by the normalization factor just created.
   • Find the maximum of the normalized correlation using the Statistics operator.

Exercises

• Perform the same experiment but in the frequency domain.