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I need a hand to be able to fix my project with opencv, which consists in detecting plates and using tesseract to extrapolate the content, but I don't understand why only the text written on a white background detects me and not when I use a real plate. I tried to arrange the image in order to make it more legible and maybe frame only the white part of the European license plates in order to simplify the extrapolation of the text, but nothing I can not isolate only the white. I using a raspberry pi 4, i don't know if it can be useful Could anyone help me? Many thanks in advance.

print("Aspetta 5 secondi per catturare l'immagine, oppure premi <space> per scattare...")

    cam = cv2.VideoCapture(0)  

    num_frames = 0
    while True:
        ret, image = cam.read()
        if not ret:
            print("La webcam non funziona...")
            sys.exit(1)

        cv2.imshow('image', image)

    # Catturo l'immagine se premo <space>
        if (cv2.waitKey(1) & 0xFF) == ord(' '):
            break

    # Aspetto 5 secondi prima di catturare l'immagine
        num_frames += 1
        if num_frames / 10 == 5:
            break

    cam.release()
    cv2.destroyAllWindows()

    cv2.imwrite("/home/pi/Desktop/Riconoscimento Targa/imagee.jpg", image)
    
    filename = 'imagee.jpg'
    
    img = np.array(Image.open(filename))
    
    img = cv2.resize(img, (600,400) )
    
    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    gray = cv2.bilateralFilter(gray, 13, 15, 15) 
    edged = cv2.Canny(gray, 30, 200) #Perform Edge detection
    
    contours=cv2.findContours(edged.copy(),cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
    contours = imutils.grab_contours(contours)
    contours = sorted(contours,key=cv2.contourArea, reverse = True)[:10]
    screenCnt = None
    
    for c in contours:
# approximate the contour
        peri = cv2.arcLength(c, True)
        approx = cv2.approxPolyDP(c, 0.018 * peri, True)
# if our approximated contour has four points, then
# we can assume that we have found our screen
        if len(approx) == 4:
            screenCnt = approx
            break
    
    
    # Masking the part other than the number plate
    mask = np.zeros(gray.shape,np.uint8)
    new_image = cv2.drawContours(mask,[screenCnt],0,255,-1,)
    new_image = cv2.bitwise_and(img,img,mask=mask)
    
    
    # Now crop
    (x, y) = np.where(mask == 255)
    (topx, topy) = (np.min(x), np.min(y))
    (bottomx, bottomy) = (np.max(x), np.max(y))
    Cropped = gray[topx:bottomx+1, topy:bottomy+1]
    
    
    
    cv2.imwrite("/home/pi/Desktop/Riconoscimento Targa/Da eliminare.jpg", Cropped)
    text = pytesseract.image_to_string(Cropped, config='--psm 11 -l ita')

    return text
Giovanni
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0 Answers0