Dividing the Image into 8 equal parts and calculate number of pixels under the line

I have lena image in Matlab. First I need to find the centroid C, then divide the image into 8 equal parts and then calculate the number of pixels under each line. I can calculate the centroid of the image but from that how can I divide the image into equal number of parts as shown below. Please, anyone help me.

Thanks

Answer 1

[Image Analyst]

See the FAQ: http://matlab.wikia.com/wiki/FAQ#How_do_I_split_an_image_into_non-overlapping_blocks.3F