问题

如何调整彩色图像的饱和度和亮度

解决思路

详细步骤：

1. 将RGB图像值归一化到[0, 1]
2. 然后使用函数cvtColor进行色彩空间的转换
3. 接下来可以根据处理灰度图像对比度增强伽马变换或者线性变换调整饱和度和亮度分量
4. 最后转换到RGB色彩空间

代码

# !/usr/bin/env python
# -*-encoding: utf-8-*-
# author:LiYanwei
# version:0.1import numpy as np
import cv2def main():# 加载图片 读取彩色图像image = cv2.imread('./Files_image/img1.jpg', cv2.IMREAD_COLOR)# print(image)# cv2.imshow("image", image)# 图像归一化，且转换为浮点型fImg = image.astype(np.float32)fImg = fImg / 255.0# 颜色空间转换 BGR转为HLShlsImg = cv2.cvtColor(fImg, cv2.COLOR_BGR2HLS)l = 100s = 100MAX_VALUE = 100# 调节饱和度和亮度的窗口cv2.namedWindow("l and s", cv2.WINDOW_AUTOSIZE)def nothing(*arg):pass# 滑动块cv2.createTrackbar("l", "l and s", l, MAX_VALUE, nothing)cv2.createTrackbar("s", "l and s", s, MAX_VALUE, nothing)# 调整饱和度和亮度后的效果lsImg = np.zeros(image.shape, np.float32)# 调整饱和度和亮度while True:# 复制hlsCopy = np.copy(hlsImg)# 得到 l 和 s 的值l = cv2.getTrackbarPos('l', 'l and s')s = cv2.getTrackbarPos('s', 'l and s')# 1.调整亮度（线性变换) , 2.将hlsCopy[:, :, 1]和hlsCopy[:, :, 2]中大于1的全部截取hlsCopy[:, :, 1] = (1.0 + l / float(MAX_VALUE)) * hlsCopy[:, :, 1]hlsCopy[:, :, 1][hlsCopy[:, :, 1] > 1] = 1# 饱和度hlsCopy[:, :, 2] = (1.0 + s / float(MAX_VALUE)) * hlsCopy[:, :, 2]hlsCopy[:, :, 2][hlsCopy[:, :, 2] > 1] = 1# HLS2BGRlsImg = cv2.cvtColor(hlsCopy, cv2.COLOR_HLS2BGR)# 显示调整后的效果cv2.imshow("l and s", lsImg)ch = cv2.waitKey(5)# 按 ESC 键退出if ch == 27:breakelif ch == ord('s'):# 按 s 键保存并退出# 保存结果lsImg = lsImg * 255lsImg = lsImg.astype(np.uint8)cv2.imwrite("lsImg.jpg", lsImg)break# 关闭所有的窗口cv2.destroyAllWindows()if __name__ == "__main__":main()