OpenCV

Question

我正在尝试隔离下图中的一条线，我知道一些方法，例如 CannyEdge Detection 可以检测图像中的所有线，但我正在努力寻找我想要的线有兴趣。

如能提供有关 OpenCV 工具的任何信息，我们将不胜感激。

目标是检测球场顶部的红色轮廓线（我用蓝色勾勒出来）

Answer 1

在Python/OpenCV中，你可以对线条的红色进行阈值处理，然后得到最大的轮廓或大于区域阈值的轮廓，这就是我在下面显示的..

输入：

import cv2
import numpy as np

# read image as grayscale
img = cv2.imread('red_line.png')

# threshold on red color
lowcolor = (0,0,75)
highcolor = (50,50,135)
thresh = cv2.inRange(img, lowcolor, highcolor)


# apply morphology close
kernel = np.ones((5,5), np.uint8)
thresh = cv2.morphologyEx(thresh, cv2.MORPH_CLOSE, kernel)

# get contours and filter on area
result = img.copy()
contours = cv2.findContours(thresh, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
contours = contours[0] if len(contours) == 2 else contours[1]
result = img.copy()
for c in contours:
    area = cv2.contourArea(c)
    if area > 5000:
        cv2.drawContours(result, [c], -1, (0, 255, 0), 2)


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

# save resulting images
cv2.imwrite('red_line_thresh.png',thresh)
cv2.imwrite('red_line_extracted.png',result)

阈值图像：

生成的轮廓：

OpenCV - 仅检测图像中的特定线条

OpenCV - Detect only a particular line in an image

python

line

object-detection

detection