Python-Opencv(8)-图片-shape边界检测-findContours

import cv2
import numpy as np

def stackImages(scale,imgArray):
    rows = len(imgArray)
    cols = len(imgArray[0])
    rowsAvailable = isinstance(imgArray[0], list)
    width = imgArray[0][0].shape[1]
    height = imgArray[0][0].shape[0]
    if rowsAvailable:
        for x in range (0, rows):
            for y in range(0, cols):
                if imgArray[x][y].shape[:2] == imgArray[0][0].shape [:2]:
                    imgArray[x][y] = cv2.resize(imgArray[x][y], (0, 0), None, scale, scale)
                else:
                    imgArray[x][y] = cv2.resize(imgArray[x][y], (imgArray[0][0].shape[1], imgArray[0][0].shape[0]), None, scale, scale)
                if len(imgArray[x][y].shape) == 2: imgArray[x][y]= cv2.cvtColor( imgArray[x][y], cv2.COLOR_GRAY2BGR)
        imageBlank = np.zeros((height, width, 3), np.uint8)
        hor = [imageBlank]*rows
        hor_con = [imageBlank]*rows
        for x in range(0, rows):
            hor[x] = np.hstack(imgArray[x])
        ver = np.vstack(hor)
    else:
        for x in range(0, rows):
            if imgArray[x].shape[:2] == imgArray[0].shape[:2]:
                imgArray[x] = cv2.resize(imgArray[x], (0, 0), None, scale, scale)
            else:
                imgArray[x] = cv2.resize(imgArray[x], (imgArray[0].shape[1], imgArray[0].shape[0]), None,scale, scale)
            if len(imgArray[x].shape) == 2: imgArray[x] = cv2.cvtColor(imgArray[x], cv2.COLOR_GRAY2BGR)
        hor= np.hstack(imgArray)
        ver = hor
    return ver

def getContours(img):
    #findContours 边界框
    contours,hierarchy=cv2.findContours(img,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE)
    for cnt in contours:
        area=cv2.contourArea(cnt)
        print(area)
        if area>500:
           cv2.drawContours(imgContour,cnt,-1,(255,0,0),3)
           peri = cv2.arcLength(cnt,True)
           print(peri)
           #1. 可以打印每个图形的边角坐标
           approx = cv2.approxPolyDP(cnt,0.02*peri,True)
           print(len(approx))
           objCor = len(approx)
           x,y,w,h = cv2.boundingRect(approx)
           if objCor == 3: objectType = "Tri"
           elif objCor == 5:objectType = "star"
           elif objCor == 4:
                 aspRation = w / float(h)
                 if aspRation > 0.95 and aspRation < 1.05:
                   objectType = "Square"
                 else:
                   objectType = "rectangle"
           elif objCor >10:objectType = "circle"
           else:objectType = "None"
           cv2.rectangle(imgContour,(x,y),(x+w,y+h),(0,255,0),2)
           cv2.putText(imgContour,objectType,
                       (x+(w//2)-10,y+(h//2)-10),cv2.FONT_HERSHEY_COMPLEX,0.5,
                       (0,0,0),2)

path = 'Resources/shape1.jpg'
img = cv2.imread(path)
imgContour = img.copy()

imgGray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
imgBlur = cv2.GaussianBlur(imgGray,(7,7),1)
imgCanny = cv2.Canny(imgBlur,50,50)

#计算
getContours(imgCanny)
imgBlank=np.zeros_like(img)
imgstack=stackImages(0.6,([img,imgGray,imgBlur],
                          [imgCanny,imgContour,imgBlank]))

#cv2.imshow("original", img)
#cv2.imshow("Gray", imgGray)
#cv2.imshow("Blur", imgBlur)
#cv2.imshow("Canny", imgCanny)
#cv2.imshow("imgContour", imgContour)
cv2.imshow("imgstack",imgstack)
cv2.waitKey(0)