In [1]:

    

%pylab inline


    

    




Populating the interactive namespace from numpy and matplotlib

In [26]:

    

a = imread(r"C:\Users\Public\Pictures\Sample Pictures\Jellyfish.jpg")


    

In [27]:

    

a.shape


    

    
Out[27]:





(768, 1024, 3)

In [28]:

    

a[100,100]


    

    
Out[28]:





array([  2,  38, 122], dtype=uint8)

In [29]:

    

a[100,100,0]


    

    
Out[29]:





2

In [30]:

    

imshow(a);


    

In [31]:

    

imshow(255-a);


    

In [32]:

    

imshow(a[100:600:,::, ::]);


    

In [102]:

    

b = np.zeros_like(a)


    

In [37]:

    

b[100:500, 200:400]=255


    

In [73]:

    

imshow(b)


    

    
Out[73]:





<matplotlib.image.AxesImage at 0xa4bbcf0>






    

In [71]:

    

b[700:750,700:750, 2]= 44


    

In [72]:

    

b[700:750,700:750]


    

    
Out[72]:





array([[[128, 111,  44],
        [128, 111,  44],
        [128, 111,  44],
        ..., 
        [128, 111,  44],
        [128, 111,  44],
        [128, 111,  44]],

       [[128, 111,  44],
        [128, 111,  44],
        [128, 111,  44],
        ..., 
        [128, 111,  44],
        [128, 111,  44],
        [128, 111,  44]],

       [[128, 111,  44],
        [128, 111,  44],
        [128, 111,  44],
        ..., 
        [128, 111,  44],
        [128, 111,  44],
        [128, 111,  44]],

       ..., 
       [[128, 111,  44],
        [128, 111,  44],
        [128, 111,  44],
        ..., 
        [128, 111,  44],
        [128, 111,  44],
        [128, 111,  44]],

       [[128, 111,  44],
        [128, 111,  44],
        [128, 111,  44],
        ..., 
        [128, 111,  44],
        [128, 111,  44],
        [128, 111,  44]],

       [[128, 111,  44],
        [128, 111,  44],
        [128, 111,  44],
        ..., 
        [128, 111,  44],
        [128, 111,  44],
        [128, 111,  44]]], dtype=uint8)

In [56]:

    

b[700:750, 0:100] = [255, 0 , 255 ]


    

In [45]:

    

b[700,700]


    

    
Out[45]:





array([255, 255, 255], dtype=uint8)

In [76]:

    

a.shape


    

    
Out[76]:





(768, 1024, 3)

In [75]:

    

imshow(a[300:500, 200:400]);


    

In [77]:

    

b[100:300, 400:600] = a[300:500, 200:400]


    

In [79]:

    

imshow(b);


    

In [82]:

    

imshow(a[::10, ::10]);


    

In [85]:

    

a[::4, ::4].shape


    

    
Out[85]:





(192, 256, 3)

In [86]:

    

b[:192, :256] = a[::4, ::4]
imshow(b);


    

In [95]:

    

for y in range(b.shape[0]):
    for x in range(b.shape[1]):
        if 100**2 < (x-400)**2 + (y-400)**2 < 200**2:
            b[y,x] =[255,0,255]
imshow(b);


    

In [99]:

    

for y in range(b.shape[0]):
    for x in range(b.shape[1]):
        b[y,x] =[x%255,y%255, 128+120*sin((x+y)/200.)]
imshow(b);


    

In [109]:

    

for y in range(b.shape[0]):
    for x in range(b.shape[1]):
        R = 100+120*sin(sqrt((x-300)**2 + (y-400)**2)/300.)
        G = 100+120*sin(sqrt((x-400)**2 + (y-400)**2)/700.)
        B = 100+120*cos(sqrt((x-500)**2 + (y-400)**2)/400.)
        b[y,x] = [R,G,B]
imshow(b);


    

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