Jpeg algorithm in matlab?

i am working on the jpeg algorith in matlab. i have been sucessful in splitting the image into 8*8 matrices, performing dct and inverse dct on it(to reconstruct the image) all in one loop. but i dont know how to recombine the 8*8 matrices into one and get the image back... since i am using only the basic commands and not image processing toolbox, i cannot use blkproc.. can anyone help me ???