How to Split Image Into Multiple Pieces in Python

I'm trying to split a photo into multiple pieces using PIL.

def crop(Path,input,height,width,i,k,x,y,page):
    im = Image.open(input)
    imgwidth = im.size[0]
    imgheight = im.size[1]
    for i in range(0,imgheight-height/2,height-2):
        print i
        for j in range(0,imgwidth-width/2,width-2):
            print j
            box = (j, i, j+width, i+height)
            a = im.crop(box)
            a.save(os.path.join(Path,"PNG","%s" % page,"IMG-%s.png" % k))
            k +=1

but it doesn't seem to be working. It splits the photo but not in an exact way (you can try it).

from PIL import Image

def crop(path, input, height, width, k, page, area):
    im = Image.open(input)
    imgwidth, imgheight = im.size
    for i in range(0,imgheight,height):
        for j in range(0,imgwidth,width):
            box = (j, i, j+width, i+height)
            a = im.crop(box)
            try:
                o = a.crop(area)
                o.save(os.path.join(path,"PNG","%s" % page,"IMG-%s.png" % k))
            except:
                pass
            k +=1