#odpuszczamy czesc 2
import numpy as np
import matplotlib.pyplot as pl
from scipy import misc as mc
from numpy import *


def histogram(image, N):
	[x,y] = image.shape
	hist = np.zeros((1,N),dtype=np.int)
	step = 255/N
	step = np.round(step)
	for pixelX in range(0,x):
		for pixelY in range(0,y):
			value = np.floor(image[pixelX,pixelY]/step)+1
			value = np.int8(value)
			hist[0][value]=(hist[0][value])+1
	return hist[0]


#
def histMinMax(hist):
	min = 0
	max = 255
	for i in range(0, 255):
		if(hist[i]>100):
			min = i
			break
	for j in range(0, 255):
		if(hist[-j]>100):
			max = 255 -j
			break
	return min, max


#
def exten(image, min, max):
	img=np.copy(image)
	[x,y]=img.shape
	vec=np.arange(255)
	for i in range(0, 255):
		if(vec[i]<min):
			vec[i]=0
		elif(vec[i]>max):
			vec[i]=255
		else:
			vec[i]=(255/(max-min)) *(i-min)
	for pixelX in range(0,x):
		for pixelY in range(0,y):
			intValue=np.int8(img[pixelX][pixelY])
			img[pixelX][pixelY]=vec[intValue]

	return img

def normal(imageMatrix):
	h=histogram(imageMatrix,255)
	[x,y]=imageMatrix.shape
	dystr=zeros((1,255),dtype=np.float)
	dystr=dystr[0]
	pixels=x*y
	a=0.0
	for i in range(0, 255):
		a=a+h[i]
		dystr[i]=a/pixels

	vec=zeros((1,255),dtype=np.int)
	vec=vec[0]
	for i in range(0, 255):
		value = ((dystr[i]-dystr[0])/(1.0-dystr[0]))*255.0
		vec[i]=value.astype(int)

	im=np.copy(imageMatrix)
	for pixelX in range(0, x):
		for pixelY in range(0, y):
			a=np.int8(im[pixelX][pixelY])
			im[pixelX][pixelY]=vec[a]
	return im


img = mc.imread('kierowca.png')
img=np.mean(img,2)

size=255
h=histogram(img, size)
[min,max]=histMinMax(h)
print("min: {0}, max: {1}".format(min,max))

img2=np.copy(img)
img2=exten(img2,min,max)

h2=histogram(img2, size)
size_vec=range(size)

img3=normal(img)
h3=histogram(img3, size)


pl.subplot(3, 2, 1)
pl.ylabel('Normalny')
pl.imshow(img,cmap='gray', vmin=0, vmax=255)
pl.subplot(3, 2, 2)
pl.bar(size_vec,h,1,color='blue')

pl.subplot(3, 2, 3)
pl.ylabel('Rozciagniety')
pl.imshow(img2,cmap='gray', vmin=0, vmax=255)
pl.subplot(3, 2, 4)
pl.bar(size_vec,h2,1,color='blue')

pl.subplot(3,2,5)
pl.ylabel('Wyrownany')
pl.imshow(img3,cmap='gray',vmin=0,vmax=255)
pl.subplot(3,2,6)
pl.bar(size_vec,h3,1,color='blue')

pl.show()






#