def get(self): #master_image = db.get(self.request.get("img_id")) master_image = open("img.jpg").read() # Create block for all items in DB blocks = [ ImageBlock(img.data) for img in ImageModel.all() ] mosaic = Mosaic(master_image, blocks) image_out = mosaic.get_image() self.response.headers['Content-Type'] = "image/png" self.response.out.write(image_out)