The CORR2 function implements the Pearson correlation to 2-D arrays. The Pearson definition of correlation is available on:
K. Pearson, "Mathematical contributions to the theory of evolution. III. Regression, heredity and panmixia" Philos. Trans. Royal Soc. London Ser. A , 187 (1896) pp. 253–318
The CORR2 function applies this definition to bidimensional array introducing a data type conversion to double and applying linear indexing to the array itself. This function is specifically developed to process pixel images often represented by uint8 data type.
