What is the difference between the 'filter' function and the 'imfilter' function?

I applied filters to cameraman.tif using

h = [2,0,-4,-3,5,19,26,19,5,-3,-4,0,2]/64. 
Im1 = filter(h, 1, Im0); Im2 = imfilter(Im0, h);

where Im0 is the image, cameraman.tif.

I expected the results of the filtered image to be the same. But it turns out that it is not the case.

Can anyone enlighten me with an explanation?