ImageCorrelate

ImageCorrelate[image, ker] gives the correlation of image with kernel ker.

ImageCorrelate[image, ker, f] computes a generalized correlation using function f.

Examples

Correlate with a kernel:

img = ExampleData[{"TestImage", "Lena"}];
ImageCorrelate[img, GaussianMatrix[3]]

Template matching:

template = ImageTake[img, {100, 150}, {100, 150}];
ImageCorrelate[img, template]

Please visit the official Wolfram Language Reference for more details.