python实现DCT算法
时间: 2023-09-29 08:11:20 浏览: 129
一个可行的DCT变换算法
以下是Python实现DCT算法的示例代码:
```
import numpy as np
def dct_1d(signal):
"""一维离散余弦变换"""
length = len(signal)
dct_signal = np.zeros(length)
for i in range(length):
sum = 0
for j in range(length):
sum += signal[j] * np.cos(np.pi * i * (j + 0.5) / length)
dct_signal[i] = sum
return dct_signal
def dct_2d(image):
"""二维离散余弦变换"""
height, width = image.shape
dct_image = np.zeros((height, width))
for i in range(height):
dct_image[i, :] = dct_1d(image[i, :])
for j in range(width):
dct_image[:, j] = dct_1d(dct_image[:, j])
return dct_image
```
使用示例:
```
import cv2
# 读取图像
image = cv2.imread('lena.png', cv2.IMREAD_GRAYSCALE)
# 进行离散余弦变换
dct_image = dct_2d(image)
# 显示结果
cv2.imshow('Original Image', image)
cv2.imshow('DCT Image', dct_image.astype(np.uint8))
cv2.waitKey(0)
cv2.destroyAllWindows()
```
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