The TemplateMatchingMethod defines the method that is used by the underlying template matching algorithm. For the formula used to calculate the similarity, please see here.
Sqdiff: Square difference (CV-TM-SQDIFF). A lower value in the match result means a better match.
SqdiffNormed: Use normed square difference (CV_TM_SQDIFF_NORMED). A lower value in the match result means a better match.
Ccorr: Cross correlation (CV_TM_CCORR). A higher value in the match result means a better match.
CCorrnormed: Use normed cross correlation (CV_TM_CCORR_NORMED). A higher value in the match result means a better match.
CCoeff: Use CV_TM_CCOEFF. A higher value in the match result means a better match.
CCoeffNormed: Use CV_TM_CCOEFF_NORMED. A higher value in the match result means a better match.