5.image_crop_by_pixcels.py

import numpy as np
import scipy.misc
from scipy import ndimage
import matplotlib.pyplot as plt

face = scipy.misc.face(gray=True)
lx, ly = face.shape
# print(lx)
# print(ly)
# Cropping
# lxstart = lx // 4
# lxend = -lx // 4
# print('\n',lxstart)
# print('\n',lxend)


crop_face = face[lx//4:-lx//4, ly//4:-ly//4]
# print(crop_face);
# up <-> down flip
flip_ud_face = np.flipud(face)
# rotation
rotate_face = ndimage.rotate(face, 45)
rotate_face_noreshape = ndimage.rotate(face, 45, reshape=False)

plt.figure(figsize=(12.5, 2.5))

plt.subplot(151)
plt.imshow(face, cmap=plt.cm.gray) # show a normal greay image
plt.axis('off') 
plt.subplot(152)
plt.imshow(crop_face, cmap=plt.cm.gray)
plt.axis('off')
plt.subplot(153)
plt.imshow(flip_ud_face, cmap=plt.cm.gray)
plt.axis('off')
plt.subplot(154)
plt.imshow(rotate_face, cmap=plt.cm.gray)
plt.axis('off')
plt.subplot(155)
plt.imshow(rotate_face_noreshape, cmap=plt.cm.gray)
plt.axis('off')

plt.subplots_adjust(wspace=0.02, hspace=0.3, top=1, bottom=0.1, left=0,
                    right=1)

plt.show()