OpenCV 2.4查找连接的组件

Question

I am trying to implement an OCR application. I want to find groups of words and for each word, I want to then find the contour of each individual character. I have found the contour for each word but I am having trouble displaying the contour for each individual character. My code so far:

imgInput = cv2.imread("inputImage.jpg")            

# convert image to grayscale
imgGray = cv2.cvtColor(imgInput, cv2.COLOR_BGR2GRAY)         

# invert black and white
newRet, binaryThreshold = cv2.threshold(imgGray,127,255,cv2.THRESH_BINARY_INV)

# dilation
rectkernel = cv2.getStructuringElement(cv2.MORPH_RECT,(15,10))

rectdilation = cv2.dilate(binaryThreshold, rectkernel, iterations = 1)

outputImage = imgInput.copy()

npaContours, npaHierarchy = cv2.findContours(rectdilation.copy(),        
                                             cv2.RETR_EXTERNAL,                 
                                             cv2.CHAIN_APPROX_SIMPLE)           

for npaContour in npaContours:                         
    if cv2.contourArea(npaContour) > MIN_CONTOUR_AREA:          

        [intX, intY, intW, intH] = cv2.boundingRect(npaContour)         

        cv2.rectangle(outputImage,           
              (intX, intY),                 # upper left corner
              (intX+intW,intY+intH),        # lower right corner
              (0, 0, 255),                  # red
              2)                            # thickness

        # Get subimage of word and find contours of that word
        imgROI = binaryThreshold[intY:intY+intH, intX:intX+intW]   


        subContours, subHierarchy = cv2.findContours(imgROI.copy(),        
                                             cv2.RETR_EXTERNAL,                 
                                             cv2.CHAIN_APPROX_SIMPLE) 

        # This part is not working as I am expecting
        for subContour in subContours:

            [pointX, pointY, width, height] = cv2.boundingRect(subContour) 

            cv2.rectangle(outputImage,
                         (intX+pointX, intY+pointY),            
                         (intX+width, intY+height),       
                         (0, 255, 0),
                         2)



cv2.imshow("original", imgInput)
cv2.imshow("rectdilation", rectdilation)
cv2.imshow("threshold", binaryThreshold)
cv2.imshow("outputRect", outputImage)

cv2.waitKey(0);

Answer 1

Everything is correct, there is just a slight bug : Change your 2nd cv2.rectangle (in the subcontours)

cv2.rectangle(outputImage,(intX+pointX, intY+pointY),(intX+pointX+width, intY+pointY+height), (0, 255, 0),2)

Not to be mean or petty, but this is a bug you could have solved yourself ;) Debugging for this sort of code is trying only for the first word, then the first subcontour, saving the images, checking values of pointX, intX, width... nothing too complicated, and it's something you'll often need to do as a programmer.

Good luck !