Hough 线检测到太多线

Question

我正在尝试使用 opencv 中的霍夫线从织物图像中提取垂直线。我应用对比度增强来增强线条和双边过滤以尝试去除其他织物纹理。但是，在应用 houghlines 时，代码会检测整个图像的线条。我试着调整 hough 的参数，但结果是一样的。

应用直方图均衡和双边滤波器后的输入图像：

这是应用霍夫线后的图像，红色代表检测到的线。显示 hough 检测的输出：

我可以尝试的另一种方法是什么，这样 hough 就不会开始将微小的织物图案也检测为线条？

这是我的代码：

`

    img1= cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
    img2 = cv2.equalizeHist(img1)
    img3 = cv2.equalizeHist(img2)
    img4 = cv2.equalizeHist(img3)
    img5 = cv2.bilateralFilter(img4, 9, 75,75)
    cv2.imshow("threshold",img5)
    edges = cv2.Canny(img4,50,127,apertureSize = 3)
    lines= cv2.HoughLines(edges, 1, math.pi/180.0, 200, np.array([]), 0, 0)
    a,b,c = lines.shape
    for i in range(a):
        rho = lines[i][0][0]
        theta = lines[i][0][1]
        a = math.cos(theta)
        b = math.sin(theta)
        x0, y0 = a*rho, b*rho
        pt1 = ( int(x0+1000*(-b)), int(y0+1000*(a)) )
        pt2 = ( int(x0-1000*(-b)), int(y0-1000*(a)) )
        cv2.line(img, pt1, pt2, (0, 0, 255), 2, cv2.LINE_AA)

cv2.imshow('image1',img)
cv2.waitKey(0)
cv2.destroyAllWindows()`

Answer 1

您需要对均衡图像进行阈值处理，应用形态学对其进行清理，然后再进行精明的边缘检测和霍夫线提取。使用Python/OpenCV做如下处理。

输入：

import cv2
import numpy as np
import math

# read image
img = cv2.imread('fabric_equalized.png')

# convert to grayscale
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

# threshold
thresh = cv2.threshold(gray,165,255,cv2.THRESH_BINARY)[1]

# apply close to connect the white areas
kernel = np.ones((15,1), np.uint8)
morph = cv2.morphologyEx(thresh, cv2.MORPH_OPEN, kernel)
kernel = np.ones((17,3), np.uint8)
morph = cv2.morphologyEx(morph, cv2.MORPH_CLOSE, kernel)

# apply canny edge detection
edges = cv2.Canny(img, 175, 200)

# get hough lines
result = img.copy()
lines= cv2.HoughLines(edges, 1, math.pi/180.0, 165, np.array([]), 0, 0)
a,b,c = lines.shape
for i in range(a):
    rho = lines[i][0][0]
    theta = lines[i][0][1]
    a = math.cos(theta)
    b = math.sin(theta)
    x0, y0 = a*rho, b*rho
    pt1 = ( int(x0+1000*(-b)), int(y0+1000*(a)) )
    pt2 = ( int(x0-1000*(-b)), int(y0-1000*(a)) )
    cv2.line(result, pt1, pt2, (0, 0, 255), 2, cv2.LINE_AA)


# save resulting images
cv2.imwrite('fabric_equalized_thresh.jpg',thresh)
cv2.imwrite('fabric_equalized_morph.jpg',morph)
cv2.imwrite('fabric_equalized_edges.jpg',edges)
cv2.imwrite('fabric_equalized_lines.jpg',result)

# show thresh and result    
cv2.imshow("thresh", thresh)
cv2.imshow("morph", morph)
cv2.imshow("edges", edges)
cv2.imshow("result", result)
cv2.waitKey(0)
cv2.destroyAllWindows()

阈值图像：

形态学清理图像：

边缘图像：

生成的 Hough 线：

Hough 线检测到太多线

Hough Lines detecting too many lines

python

opencv

image-processing

hough-transform

opencv-python