Image windowing for doing emgm

Hi I want to do windowing on an image then run EM algorithm on it.I used both blockproc and colfilt but both of them cause error. I face many error for using blockproc but one error:

Error using ==> reshape
To RESHAPE the number of elements must not change.

Error in ==> colfilt at 183
                b(i*mb+brows,j*nb+bcols) = ..

for using colfilt. what do you recommend me to do?

Thank you

Answer 1

[Image Analyst]

I recommend you give enough information for us to be able to solve your problem.

[bahar h]

actually I am supposed to simulate a paper in which I should calculate the joint probability density of gray levels of a suitably chosen search window in a mammogram:x=(x1,x2,...xn),assume the joint probability in form of Gaussian components.finally I should have a data set S by pixelwise scaning of the mammogram with the search window :S={x(1),x(2),...}.and then obtain Gaussian mixture model and maximum likelihood by EM algorithm,I think for these parts(GMM &EM)I can use stprtool but I have problem with search window yet.my image is a 1024*1024 uint8 and the size of window used in the paper is 13*13 pixels with trimmed corner?(I don't know trimmed corner and I am not sure it be necessary?)my mammogram belong to a database other than the mentioned paper but I hope they be the same size. Thank you

[Image Analyst]

I'm not sure what the question is, but when you scan an image with a window, yes, you are going to have to know how to handle the edge conditions where the window is "off" the edge of the image. This is a common situation in image processing and there are a variety of ways to handle partial windows, such as assuming image is zero for window pixels not over an image, or just ignoring those pixels, or renormalizing, etc.