Keras: preprocessing_function && random_crop

Origin Image:

random_crop:

from keras.preprocessing.image import ImageDataGenerator, array_to_img, img_to_array, load_img from scipy import misc  import numpyimport numpy.randomimport scipy.ndimageimport scipy.miscdef random_crop_image(image):      height, width = image.shape[:2]      random_array = numpy.random.random(size=4);      w = int((width*0.5)*(1+random_array[0]*0.5))      h = int((height*0.5)*(1+random_array[1]*0.5))      x = int(random_array[2]*(width-w))      y = int(random_array[3]*(height-h))      image_crop = image[y:h+y,x:w+x,0:3]      image_crop = misc.imresize(image_crop,image.shape)      return image_cropdatagen = ImageDataGenerator(        rotation_range=10,        width_shift_range=0.1,        height_shift_range=0.1,        shear_range=0.1,        preprocessing_function=random_crop_image,        zoom_range=0.1,        horizontal_flip=True,        fill_mode='reflect')img = load_img('lena.jpg') x = img_to_array(img)x = x.reshape((1,) + x.shape)i = 0for batch in datagen.flow(x,batch_size=1,save_to_dir='preview',save_prefix='/home/yan/Desktop/test/test/', save_format='jpg'):    i += 1    if i > 20:        break  # 否则生成器会退出循环