在python中获取图像的指定像素数

Question

I have a code to get the first pixel of an image. But I can't limit the number of pixel numbers. I want to get the first three pixels of an image ie 9 RGB value.Here is my code .

from PIL import Image
import numpy as np
import cv2

img = cv2.imread('images.jpeg')
a=img.shape
rows=a[0]
cols=a[1]
string=raw_input("Enter a message ")
l=len(string)
m=0
n=0
for i in range(0,rows):
    for j in range(0,cols):
        first= img[i,j]
        print first
        break
    break

Answer 1

Image is a 2D matrix in Python. The first pixel is the one at top left corner. However, it is hard to define the first 3 pixels. It is up to you. The code is as follows.

import cv2

img = cv2.imread('images.jpeg')        
print img[0,0], img[0,1], img[1,0]