how to calculate image prediction ?

i was asked to calculate correlation between pixels

and then to claculate the prediction of image with this hint :

e(i,j)=img(i,j)- img(i,j-l) if i=0

e(i,j)=img(i,j)-img(i-l,j) if j=0

and then the correlation of this image

anyone can help me please !!,