python-3.xocrtesseractpython-tesseracttext-extraction

Using Tesseract not able to identify single character from the image

I tried to extract the number from the attached image

[Image having number

But I am not getting the number 8 as an output. I tried with different PSM values as well like 6, 10 etc.

This is what I have so far:

image = cv2.imread(image_path)
if(image is not None):
# Convert the image to grayscale
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)

    # Use OCR to extract text from the image
    extracted_text = pytesseract.image_to_string(gray, config='--psm 10 -c tessedit_char_whitelist=0123456789')
Solution

  • Even though the image looks good for OCR, there is some shading from the vertical line that is detrimental to the detection. I did some thresholds and eventually got this image:

    mask

    I feed this to the tesseract and I get the "8":

    import cv2
import pytesseract
pytesseract.pytesseract.tesseract_cmd = "C:/Program Files/Tesseract-OCR/tesseract.exe"
im = cv2.imread("8.png") # read
b,g,r = cv2.split(im) # split
mask = (b>200)*(r<200)*(g<200) # threshold
text = pytesseract.image_to_string(mask, config='-l eng --psm 10') # use 
print(text) # print, results is "8"

    Of course, this will fail if other colours are involved. If you have this situation, can you post more images so I can adjust the code?