import cv2

import numpy as np

# 读取图像

img = cv2.imread('../res/img/baboon.bmp')

# 灰度化

img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# 显示原图

cv2.imshow('img', img)

# 获取图像宽高

height, width = img.shape

# 对图像进行 dct 变换

img_dct = cv2.dct(np.array(img, np.float32))

# 去除部分低频信息

img_dct[0:100, 0:100] = 0

# 进行反 dct 变换

img_idct = np.array(cv2.idct(img_dct), np.uint8)

# 显示图像

cv2.imshow('img_dct', np.array(img_dct, np.uint8).reshape(width, height))

cv2.imshow('img_idct', img_idct.reshape(width, height))

cv2.waitKey(0)