Question

它的计算方法类似于面积/凸包区域之间的比率：

#calculating area from contour
area = cv2.contourArea(unicocnt)

#calculating hull and hull area
hull = cv2.convexHull(unicocnt) 
hull_area = cv2.contourArea(hull)

#solidity
solidity = float(area)/hull_area

计算对于圆形图像，我得到的所有值都接近1，所以我想当我计算轮廓的面积时，我计算圆内的面积而不考虑内部是否是白色像素（轮廓是黑色）

图片示例：https://docs.google.com/file/d/0ByS6Z5WRz-h2b0JITFB4aHR0OWc/edit?usp=sharing

CODE：

nomeimg = 'Riscalate2/JPEG/e (5).jpg'

img = cv2.imread(nomeimg)

gray = cv2.imread(nomeimg,0)#convert grayscale adn binarize

element = cv2.getStructuringElement(cv2.MORPH_CROSS,(6,6)) 
graydilate = cv2.erode(gray, element) #imgbnbin

cv2.imshow('image',graydilate)
cv2.waitKey(0)

ret,thresh = cv2.threshold(graydilate,127,255,cv2.THRESH_BINARY_INV)   # binarize

imgbnbin = thresh
cv2.imshow('bn',thresh)
cv2.waitKey()

#element = cv2.getStructuringElement(cv2.MORPH_CROSS,(2,2))
#element = np.ones((11,11),'uint8')


contours, hierarchy = cv2.findContours(imgbnbin, cv2.RETR_TREE ,cv2.CHAIN_APPROX_SIMPLE)
print(len(contours))


# Take only biggest contour basing on area
Areacontours = list()
calcarea = 0.0
unicocnt = 0.0
for i in range (0, len(contours)):
    area = cv2.contourArea(contours[i])
    #print("area")
    #print(area)
    if (area > 90 ):  #con 90 trova i segni e togli puntini
        if (calcarea<area):
            calcarea = area
            unicocnt = contours[i]

#calculating area from contour
area = cv2.contourArea(unicocnt)

#calculating hull and hull area
hull = cv2.convexHull(unicocnt) 
hull_area = cv2.contourArea(hull)

#solidity
solidity = float(area)/hull_area

更新

我是这样做的：

ColoredArea = 0
for i in range(0,len(imgbnbin)):
    a = imgbnbin[i]
    for j in range (0, len(a)):
        if (cv2.pointPolygonTest(hull, unicocnt) >= 0):        
            if (getPixel(x,y) == black):
                ColoredArea = ColoredArea +1;

出现此错误：

if (cv2.pointPolygonTest(hull, unicocnt) >= 0):
TypeError: Required argument 'measureDist' (pos 3) not found

Answer 1

尝试以下算法（伪代码）：

int ColoredArea = 0;
for (x=MinX to MaxX)
   for (y=MinY to MaxY)
        if (cv2.pointPolygonTest(hull, pt(x,y)) >= 0)
           if (getPixel(x,y) == black)
               ColoredArea++;

如何在黑色像素轮廓上计算opencv中的Solidity？

1 个答案: