How to draw bounding boxes on ROI using opencv

Question

This is the image:

And these are the key-value pairs in a text file:

camera: LG G3 D855
reading: 05501
position: 843 1492 572 119
    digit 1: 855 1513 54 98
    digit 2: 971 1512 61 100
    digit 3: 1092 1512 61 100
    digit 4: 1207 1501 64 99
    digit 5: 1341 1499 38 97

I need to draw bounding boxes around digits. This is my code:

for i in image_list:
    img = cv2.imread(os.path.join(image_dir,i))
    img = cv2.cvtColor(img,cv2.COLOR_BGR2RGB)
    matching = [s for s in text_files if i.replace(".jpg","") in s]
    myvars = {}
    with open(str(matching[0])) as myfile:
        for line in myfile:
            print(line)
            name, var = line.partition(":")[::2]
            myvars[name.strip()] = var
    digits1 = myvars["digit 1"].split(" ")
    print(digits1[1])
    pts1 = (digits1[1], digits1[2])
    pts2 = (digits1[1]+digits1[3], digits1[2]+digits1[4])
    cv2.rectangle(img, pts1 , pts2 , (255,0,0), 2)
    cv2.imshow("lalala", img)
    k = cv2.waitKey(0) # 0==wait forever

This is giving this error:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-40-8ed670a7caaf> in <module>
     26     pts1 = (digits1[1], digits1[2])
     27     pts2 = (digits1[1]+digits1[3], digits1[2]+digits1[4])
---> 28     cv2.rectangle(img, pts1 , pts2 , 0, 2)
     29     cv2.imshow("lalala", img)
     30     k = cv2.waitKey(0) # 0==wait forever

TypeError: an integer is required (got type tuple)

How do I resolve this?

Answer 1

When you split a string, in the output you will get a string but for rectangle function, you need to convert these strings to int . So you have some mistakes in these lines:

digits1 = myvars["digit 1"].split(" ")
print(digits1[1])
pts1 = (digits1[1], digits1[2])  // a mistake happened in here
pts2 = (digits1[1]+digits1[3], digits1[2]+digits1[4])  // a mistake happened in here

You should convert these strings to int as below:

pts1 = (int(digits1[1]), int(digits1[2]))
pts2 = (int(digits1[1])+int(digits1[3]), int(digits1[2])+int(digits1[4]))