slicer.py

#!/usr/bin/env python2.7
from __future__ import division
from PIL import Image
import math
import os


def long_slice(image_path, out_name, outdir, slice_size):
   """slice an image into parts slice_size tall"""
   img = Image.open(image_path)
   width, height = img.size
   upper, left = 0, 0
   slices = int(math.ceil(height/slice_size))

   count = 1
   for slice in range(slices):
       # if we are at the end, set the lower bound to be the bottom of the image
       if count == slices: lower = height
       else: lower = int(count * slice_size)   
       # set the bounding box! The important bit      
       bbox = (left, upper, width, lower)
       working_slice = img.crop(bbox)
       upper += slice_size
       # save the slice
       slice_name = './' + out_name + "/slice_"
       working_slice.save(os.path.join(outdir, slice_name + out_name + "_" + \
           str(count) + ".png"))
       count +=1


def check_if_directory_exists(directory):
   """creats a directory if it doesn't exist"""
   if not os.path.exists(directory): 
      os.makedirs(directory)


if __name__ == '__main__':
   check_if_directory_exists("left")
   check_if_directory_exists("right")

   img = Image.open('warp_speed.5978d1405660e365872cf72dddc7515603f657f12526bd61e56feacf332cccad.jpg')
   w, h = img.size
   half_width = int(w/2)
   img_left = img.crop((0, 0, half_width, h)).save('warp-left.png')
   img_right = img.crop((half_width, 0, w, h)).save('warp-right.png')

   # slice_size is the max height of the slices in pixels
   long_slice("warp-right.png", "right", os.getcwd(), 7)
   long_slice("warp-left.png", "left", os.getcwd(), 7)