Quickly generate images containing your samples and your background images.

image_generator.py

import Image
import os
import random

training_images = []
training_path = 'cropped'
background_images = []
background_path = 'background'
training_file = 'train'

def get_image_list(file_path):
	return os.listdir(file_path)

def rotate_randomely(im):
	number = random.randint(1, 6)
	if number == 1:
		return im.transpose(Image.FLIP_LEFT_RIGHT)
	elif number == 2:
		return im.transpose(Image.FLIP_TOP_BOTTOM)
	elif number == 3:
		return im.transpose(Image.ROTATE_90)
	elif number == 4:
		return im.transpose(Image.ROTATE_180)
	elif number == 5:
		return im.transpose(Image.ROTATE_270)
	else:
		return im

def get_random_point(maxX, maxY):
	x = random.randint(0, maxX)
	y = random.randint(0, maxY)
	return x, y	

def insert_image(from_image, onto_image):

	from_image = resize_smaller(from_image, onto_image.size)
	x, y = get_random_point(onto_image.size[0] - from_image.size[0], onto_image.size[1] - from_image.size[0])
	onto_image.paste(from_image, (x, y))
	width = from_image.size[0]
	height = from_image.size[1]
	return x, y, width, height

def resize_smaller(image, maxXY):
	if image.size[0] > maxXY[0] or image.size[1] > maxXY[1]:
		image = image.resize((image.size[0] / 2, image.size[1] / 2))
	if image.size[0] > maxXY[0] or image.size[1] > maxXY[1]:
		resize_smaller(image, maxXY)
	else:
		return image

training_images = get_image_list(training_path)
background_images =  get_image_list(background_path)


index = 0
for training_image in training_images:
	for background_image in background_images:
		name = background_image
		training_img = Image.open(os.path.join(training_path, training_image))
		background_image = Image.open(os.path.join(background_path, background_image))
		training_img = rotate_randomely(training_img)
		x, y, width, height = insert_image(training_img, background_image)
		full_name = 'images/' + str(index) + name
		background_image.save(full_name)
		with open("train", "a") as f:
			f.write(full_name)
			f.write(' ')
			f.write('1 ' + str(x) + ' ' + str(y) + ' ' + str(width) + ' ' + str(height))
			f.write('\n')
		index = index + 1