正交梯度法检测边缘点例题代码
时间: 2023-09-09 15:10:49 浏览: 52
以下是用Python实现正交梯度法检测边缘点的例题代码:
```python
import cv2
import numpy as np
# 读取图像
img = cv2.imread('test.jpg', cv2.IMREAD_GRAYSCALE)
# 高斯滤波
img = cv2.GaussianBlur(img, (3, 3), 0)
# 计算水平和垂直方向上的梯度
sobelx = cv2.Sobel(img, cv2.CV_64F, 1, 0, ksize=3)
sobely = cv2.Sobel(img, cv2.CV_64F, 0, 1, ksize=3)
# 计算正交方向上的梯度
mag = np.sqrt(sobelx**2 + sobely**2)
if mag.max() > 0:
sobelx /= mag.max()
sobely /= mag.max()
# 检测边缘点
edge = np.zeros(img.shape, dtype=np.uint8)
for i in range(1, img.shape[0]-1):
for j in range(1, img.shape[1]-1):
if sobelx[i,j] > 0 and sobely[i,j] > 0 and sobelx[i,j] >= sobely[i,j]:
if sobelx[i,j] > sobelx[i,j-1] and sobelx[i,j] > sobelx[i,j+1]:
edge[i,j] = 255
elif sobelx[i,j] < 0 and sobely[i,j] < 0 and abs(sobelx[i,j]) >= abs(sobely[i,j]):
if abs(sobelx[i,j]) > abs(sobelx[i,j-1]) and abs(sobelx[i,j]) > abs(sobelx[i,j+1]):
edge[i,j] = 255
elif sobelx[i,j] < 0 and sobely[i,j] > 0 and abs(sobelx[i,j]) >= sobely[i,j]:
if abs(sobelx[i,j]) > sobely[i,j-1] and abs(sobelx[i,j]) > sobely[i,j+1]:
edge[i,j] = 255
elif sobelx[i,j] > 0 and sobely[i,j] < 0 and sobelx[i,j] <= abs(sobely[i,j]):
if sobelx[i,j] > abs(sobely[i,j-1]) and sobelx[i,j] > abs(sobely[i,j+1]):
edge[i,j] = 255
# 显示结果
cv2.imshow('Original Image', img)
cv2.imshow('Edge Detection', edge)
cv2.waitKey(0)
cv2.destroyAllWindows()
```
其中,`test.jpg`是待检测的图像文件。该代码首先对图像进行高斯滤波,然后计算水平和垂直方向上的梯度。接着,根据正交梯度法的思想,计算正交方向上的梯度,并根据梯度值的大小来确定图像中的边缘点。最后,显示检测结果。