对JPEG压缩后的图像进行滤泼去除压缩导致的块效应,且不能跟去噪滤波一样是全画面滤波,用python写一个程序。
时间: 2024-03-14 12:46:12 浏览: 159
基于python的JPEG图像压缩
好的,下面是一个基于边界保护和纹理保护的滤波算法的示例代码,用于对JPEG压缩后的图像进行滤泼去除压缩导致的块效应:
```python
import cv2
import numpy as np
# 读取压缩后的JPEG图像
img = cv2.imread('compressed.jpg')
# 分块大小
block_size = 16
# 相邻块之间的重叠区域大小
overlap_size = 4
# 使用基于边界保护的均值滤波算法对图像进行局部滤波
def boundary_mean_filter(block):
# 计算块的边界
h, w = block.shape[:2]
top = block[0, :, :]
bottom = block[h-1, :, :]
left = block[:, 0, :]
right = block[:, w-1, :]
# 对边界进行均值滤波
top_mean = np.mean(top, axis=0)
bottom_mean = np.mean(bottom, axis=0)
left_mean = np.mean(left, axis=0)
right_mean = np.mean(right, axis=0)
# 将边界像素值替换成均值
block[0:overlap_size, :, :] = top_mean
block[h-overlap_size:h, :, :] = bottom_mean
block[:, 0:overlap_size, :] = left_mean
block[:, w-overlap_size:w, :] = right_mean
# 对块中心区域进行均值滤波
center = block[overlap_size:h-overlap_size, overlap_size:w-overlap_size, :]
center_mean = np.mean(center, axis=(0,1))
block[overlap_size:h-overlap_size, overlap_size:w-overlap_size, :] = center_mean
return block
# 使用基于纹理保护的中值滤波算法对图像进行局部滤波
def texture_median_filter(block):
# 计算块的纹理信息
dx = cv2.Sobel(block, cv2.CV_64F, 1, 0, ksize=3)
dy = cv2.Sobel(block, cv2.CV_64F, 0, 1, ksize=3)
texture = np.abs(dx) + np.abs(dy)
# 对纹理信息进行中值滤波
texture_median = np.median(texture)
texture[texture < texture_median] = 0
texture[texture >= texture_median] = 1
# 对块进行中值滤波
for i in range(3):
channel = block[:, :, i]
channel_median = np.median(channel)
channel[texture == 1] = channel_median
return block
# 对图像进行分块处理,并对每个块进行局部滤波
h, w = img.shape[:2]
new_img = np.zeros((h, w, 3), dtype=np.uint8)
for i in range(0, h, block_size):
for j in range(0, w, block_size):
block = img[i:i+block_size, j:j+block_size, :]
block = boundary_mean_filter(block)
block = texture_median_filter(block)
new_img[i:i+block_size, j:j+block_size, :] = block
# 将处理后的图像保存到文件
cv2.imwrite('filtered.jpg', new_img)
```
在上述代码中,我们首先读取了压缩后的JPEG图像,并定义了分块和重叠区域的大小。然后,我们定义了两个函数`boundary_mean_filter`和`texture_median_filter`,分别用于基于边界保护和纹理保护的局部滤波。在`boundary_mean_filter`函数中,我们首先计算了块的边界,然后对边界进行均值滤波,最后对块中心区域进行均值滤波。在`texture_median_filter`函数中,我们首先计算了块的纹理信息,然后对纹理信息进行中值滤波,最后对块进行中值滤波。最后,我们对图像进行分块处理,并对每个块进行局部滤波,得到处理后的图像,并将其保存到文件中。
希望这个示例代码能够帮助到您实现对JPEG压缩后的图像进行滤泼去除压缩导致的块效应的功能。
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