东南大学《数字图像处理》课程作业 4

程序代码

# coding: utf-8

'''
东南大学《数字图像处理》课程 作业4 - Gamma校正
09017227 卓旭 written with Python 3

本程序内灰度图像作为二维数组，存储顺序为[行][列]，像素点坐标表示为img[x][y]，坐标系为
O--------> [y axis]
|
|
V [x axis]
'''

import imageio
import numpy as np
import cv2 # OpenCV仅用于显示图片

IMAGE_PATH='./Img_GammaCorrection.bmp'
GAMMA=1/2.8

'''
  读入灰度图像，转为二维numpy数组
'''
def readImage(imagePath):
  return imageio.imread(imagePath)

'''
  返回经过Gamma变换的图像
'''
def gammaCorrection(sourceImage, Gamma):
  targetImage = np.zeros(sourceImage.shape, dtype=np.uint8)
  # 归一化
  normSourceImage = sourceImage / 255
  for i in range(targetImage.shape[0]):
    for j in range(targetImage.shape[1]):
      targetImage[i][j] = np.uint8(pow(normSourceImage[i][j], Gamma) * 255)
  return targetImage

if __name__ == '__main__':
  sourceImage = readImage(IMAGE_PATH)
  targetImage = gammaCorrection(sourceImage, GAMMA)
  imageio.imsave("Gamma_result.bmp", targetImage)
  cv2.imshow("test", targetImage)
  cv2.waitKey(0)