def autocrop(self):
border = 255
rr = (self.region_rect.left, self.region_rect.top,
self.region_rect.right, self.region_rect.bottom)
imp = self.image.crop(rr)
if self.acbwmode:
bw = imp.convert('1')
else:
bw = imp.convert('L')
bw = bw.filter(ImageFilter.MedianFilter)
bg = Image.new('1', imp.size, border)
diff = ImageChops.difference(bw, bg)
bbox = diff.getbbox()
brect = Rect((self.x0 + bbox[0], self.y0 + bbox[1]),
(self.x0 + bbox[2], self.y0 + bbox[3]))
brect = brect.valid_rect(self.w, self.h)
self.crop_rects.append(brect)
self.n = self.n + 1
self.canvas.delete(tk.ALL)
self.displayimage()
