Question

我写了一个代码段来检测交通标志的形状。该代码对于检测形状（三角形交通标志除外）相当有效。我尝试将值（即0.01）调整为函数cv2.approxPolyDP（c，0.01 * peri，True）的第二个参数，但是我找不到正确的值。

我尝试将值（即0.01）调整为函数cv2.approxPolyDP（c，0.01 * peri，True）的第二个参数，但找不到正确的值。

 from os import listdir
from os.path import isfile, join
import cv2
myPath = '/home/raghu/Downloads/SSIMProject/ImageData/sample'
files = [ f for f in listdir(myPath) if isfile(join(myPath, f))]
for eachFile in files:
    img = cv2.imread(join(myPath, eachFile), 1)
    cv2.imshow('img1', img[:,:,0])
    ret, thresh1 = cv2.threshold(img[:,:,0], 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)
    contours,hierarchy = cv2.findContours(thresh1, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)
    font = cv2.FONT_HERSHEY_COMPLEX
    for cnt in contours:
        approx = cv2.approxPolyDP(cnt, 0.0112 * cv2.arcLength(cnt, True), True)
        print(len(approx))
        if len(approx) == 8:
            print("Octagon")
            cv2.putText(img, 'Octagon', (10, 30), font, 0.3, (0, 0, 0), 1, cv2.LINE_AA)
            cv2.drawContours(img, [cnt], 0, (0, 255, 0), 2)
        elif len(approx) == 7:
            print("Heptagon")
            cv2.putText(img, 'Heptagon', (10, 30), font, 0.3, (0, 0, 0), 1, cv2.LINE_AA)
            cv2.drawContours(img, [cnt], 0, (0, 255, 0), 2)
        elif len(approx) == 6:
            print("Hexagon")
            cv2.putText(img, 'Hexagon', (10, 30), font, 0.3, (0, 0, 0), 1, cv2.LINE_AA)
            cv2.drawContours(img, [cnt], 0, (0, 255, 0), 2)
        elif len(approx) == 5:
            print("Pentagon")
            cv2.putText(img, 'Pentagon', (10, 30), font, 0.3, (0, 0, 0), 1, cv2.LINE_AA)
            cv2.drawContours(img, [cnt], 0, (0, 255, 0), 2)
        elif len(approx) == 4:
            print("Square")
            cv2.putText(img, 'Square', (10, 30), font, 0.3, (0, 0, 0), 1, cv2.LINE_AA)
            cv2.drawContours(img, [cnt], 0, (0, 255, 0), 2)
        elif len(approx) == 3:
            print("Triangle")
            cv2.putText(img, 'Triangle', (10, 30), font, 0.3, (0, 0, 0), 1, cv2.LINE_AA)
            cv2.drawContours(img, [cnt], 0, (0, 255, 0), 2)
        else:
            print("Circle")
            cv2.putText(img, 'Circle', (10, 30), font, 0.3, (0, 0, 0), 1, cv2.LINE_AA)
            cv2.drawContours(img, [cnt], 0, (0, 255, 0), 2)
    cv2.imshow('sign', img)
    cv2.waitKey(0)
    cv2.destroyAllWindows()

我希望能检测到三角形的交通标志。

Answer 1

请尝试以下代码，以帮助您检测图像中的三角形一旦您可以基于交通三角的颜色创建一个彩色滤光片（例如红色滤光片），然后使用该滤色片，使其始终仅检测红色标记

import cv2
import numpy as np
font = cv2.FONT_HERSHEY_COMPLEX

img = cv2.imread("shapes.jpg", cv2.IMREAD_GRAYSCALE)
_, threshold = cv2.threshold(img, 240, 255, cv2.THRESH_BINARY)
_, contours, _ = cv2.findContours(threshold, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

for cnt in contours:
    approx = cv2.approxPolyDP(cnt, 0.01*cv2.arcLength(cnt, True), True)
    cv2.drawContours(img, [approx], 0, (0), 5)
    x = approx.ravel()[0]
    y = approx.ravel()[1]
cv2.putText(img, "Triangle", (x, y), font, 1, (0))
cv2.imshow("shapes", img)
cv2.imshow("Threshold", threshold)
cv2.waitKey(0)
cv2.destroyAllWindows()

如何使用Opencv检测三角形交通标志

1 个答案: