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# Accessing and modifying pixel values
>>> import cv2
>>> import numpy as np
# Loadimage
>>> img = cv2.imread('messi5.jpg')
'''
You can access a pixel value by its row and column coordinates. 
For BGR image, it returns an array of Blue, Green, Red values. 
For grayscale image, just corresponding intensity is returned.
'''
>>> px = img[100,100]
>>> print px
[157 166 200]

# accessing only blue pixel
>>> blue = img[100,100,0] #blue -> 0
>>> print blue
157
# modify pixel values the same way
>>> img[100,100] = [255,255,255]
>>> print img[100,100]
[255 255 255]

# Better pixel accessing and editing method :
# accessing RED value
>>> img.item(10,10,2)
59
# modifying RED value
>>> img.itemset((10,10,2),100)
>>> img.item(10,10,2)
100

# Accessing Image Properties
# Image properties -> # of rows, columns, and channels, type of image data, pixels, etc
# Shape of img accessed by img.shape
>>> print img.shape
(342, 548, 3)
# Total number of pixels is accessed by img.size:
>>> print img.size
562248
# Image datatype is obtained by img.dtype:
>>> print img.dtype
uint8