%jasnosc i kontrast
%
%
%
%
import numpy as np
import matplotlib.pyplot as plt
from scipy import misc as mc

def warstwa(img):
    r=img[:,:,0]
    g=img[:,:,1]
    b=img[:,:,2]
    s1 = 0.2126*r + 0.7152*g + 0.0722 *b
    return s1


#
def jik():
    img2= warstwa(img)
    jasnosc=(np.sum(img2))/(M*N)
    iloraz= 1.0/(M*N)
    kontrast= np.power(iloraz* np.sum(np.power(img2-jasnosc,2)) ,0.5)


    return jasnosc, kontrast

#


img = mc.imread('kierowca.png')

print img.dtype
print img.shape
N= img.shape[1]
M= img.shape[0]
print jik()

#dla zwyklego unit8
img2= img.copy()
img2 = img2 +150

img3= img.copy()
img3= img3 * 2

img4 = img.copy()
img4=np.power(img4,0.2)

img5 = img.copy()
img4=np.power(img4,2)




#dla float64
imgfloat = img.astype('float64')

img2float= imgfloat.copy()
img2float = img2float +150

img3float= imgfloat.copy()
img3float= img3float * 2

img4float = imgfloat.copy()
img4float=np.power(img4float,0.2)

img5float = imgfloat.copy()
img5float =np.power(img5float,2)

#M= img.shape[0];
#N= img.shape[1];

#print jik()
plt.subplot(2,5,1)
plt.imshow(img)

plt.subplot(2,5,6)
plt.imshow(imgfloat)

plt.subplot(2,5,2)
plt.imshow(img2)

plt.subplot(2,5,7)
plt.imshow(img2float)

plt.subplot(2,5,3)
plt.imshow(img3)

plt.subplot(2,5,8)
plt.imshow(img3float)

plt.subplot(2,5,4)
plt.imshow(img4)

plt.subplot(2,5,9)
plt.imshow(img4float)

plt.subplot(2,5,5)
plt.imshow(img5)

plt.subplot(2,5,10)
plt.imshow(img5float)



plt.show()