CODEWITHSUNDEEP
pythonopencvtesseractorc
toto_dev
toto_dev

Reputation: 41

How can extract text from video stream?

I'm traying to extract some text from video stream coming from my camera using opencv2 and pytesseract. I crop the image to get an other small image. I trayed different image processing to get it work. I inverted the image values, blur it, binarize it, but no one of these is working with tesseract. The data that I want to extract has these form 'float/float' here is example of the small image:

Seems like the characters are not separated and this is the maximum resolution that I can get from my camera. I tried then to filter by color, but no result because it is video and the background is always moving. I will use any suggested Python module that can work.

Upvotes: 3

Views: 6026

Answers (1)

toto_dev
toto_dev

Reputation: 41

not trivial as it seems. i generated 32x32 png image for every character and add a white noise to it. the backgound on the video is moving. and caracters like 8 and 6 are not very different. here is my code for the moment:

cap = cv2.VideoCapture("rtsp:...")
time.sleep(2)
templates = {}
w=[]
h=[]
for i in range(0,11):
    templates["template_"+str(i)]=cv2.imread(str(i)+'.bmp',0)
    tmp_w,tmp_h=templates["template_"+str(i)].shape[::-1]
    w.append(tmp_w)
    h.append(tmp_h)



threshold = 0.70



while(True):
    les_points=[[],[],[],[],[],[],[],[],[],[],[]]
    ret, frame = cap.read()
    if frame==None:
      break
    crop_image=frame[38:70,11:364]
    gray=cv2.cvtColor(crop_image,cv2.COLOR_BGR2GRAY)
    for i in range(0,11):
        res= cv2.matchTemplate(gray,templates["template_"+str(i)],cv2.TM_CCOEFF_NORMED)
        loc = np.where( res >= threshold)
        for pt in zip(*loc[::-1]):
            les_points[i].append(pt[0])
            cv2.rectangle(crop_image, pt, (pt[0] + w[i], pt[1] + h[i]), (0,i*10,255), 2)
    print les_points
    cv2.imshow('normal',crop_image)
    if cv2.waitKey(1)& 0xFF == ord('p'):
        threshold=threshold+0.01
        print threshold
    if cv2.waitKey(1)& 0xFF == ord('m'):
        threshold=threshold-0.01
        print threshold
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

I'm doing other tests by split the image to the exact same size of the caracters in templates. but this is not giving good results

Upvotes: 1

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