In [5]:

    

%matplotlib inline
from matplotlib import pyplot as plt
import numpy as np

from skimage.data import coffee
from skimage.color import rgb2gray

rgb = coffee()
y = rgb2gray(rgb)

fig, (ax1, ax2) = plt.subplots(ncols=2,figsize=(15,12))

ax1.imshow(rgb)
ax2.imshow(y, cmap='gray')

y.shape


    

    
Out[5]:





(400, 600)






    

In [3]:

    

fig, (ax1, ax2) = plt.subplots(ncols=2,figsize=(15,12))

spoon = y[200:400,300:500]
crop = y[100:-100,100:-100]

ax1.imshow(spoon,cmap='gray')
ax2.imshow(crop,cmap='gray')


    

    
Out[3]:





<matplotlib.image.AxesImage at 0x7f02525f4f10>






    

In [4]:

    

fig, (ax1, ax2) = plt.subplots(ncols=2,figsize=(15,12))

s10 = y[200:400:4,300:500:4]
y10 = y[::10,::10]

ax1.imshow(s10,cmap='gray',interpolation='nearest')
ax2.imshow(y10,cmap='gray',interpolation='nearest')


    

    
Out[4]:





<matplotlib.image.AxesImage at 0x7f02524504d0>






    

In [5]:

    

h, w = y.shape

s = np.flipud(y)
r = np.roll(y,w//2,axis=1)

fig, (ax1, ax2) = plt.subplots(ncols=2,figsize=(15,12))

ax1.imshow(s,cmap='gray')
ax2.imshow(r,cmap='gray')


    

    
Out[5]:





<matplotlib.image.AxesImage at 0x7f0252330050>






    

In [6]:

    

from skimage.transform import resize, rescale

sq = resize(y,(512,512))
sq_small = rescale(y,0.1)

fig, (ax1, ax2) = plt.subplots(ncols=2,figsize=(15,12))

ax1.imshow(sq,cmap='gray')
ax2.imshow(sq_small,cmap='gray',interpolation='nearest')


    

    
Out[6]:





<matplotlib.image.AxesImage at 0x7f024309da10>