Pytesseract image_to_string empty output

Question

I have this image that was cropped from another image and I want to give this image as an input to image_to_string method:

import pytesseract
import cv2
num_plate = cv2.imread('E:\Images\car_plate222.jpeg' , cv2.IMREAD_GRAYSCALE)
pytesseract.pytesseract.tesseract_cmd = r'C:\Program Files\Tesseract-OCR\tesseract.exe'
cv2.dilate(num_plate, (15, 15), num_plate)
pytesseract.image_to_string(num_plate)

Here's the photo: Car Plate:

I used dilation for better performance, but it doesn't give me desired output (Sometimes gives me empty string and sometimes gives me weird output)

Does anybody know what's wrong?

Answer 1

You must threshold the image before passing it to pytesseract . That increases the accuracy. Here is a sample:

import cv2
import numpy as np
import pytesseract
from PIL import Image

# Grayscale image
img = Image.open('E:\\WorkDir\\KAVSEE\\Python\\test.jpg').convert('L')  
ret,img = cv2.threshold(np.array(img), 125, 255, cv2.THRESH_BINARY)

# Older versions of pytesseract need a pillow image
# Convert back if needed
img = Image.fromarray(img.astype(np.uint8))

print(pytesseract.image_to_string(img))

Hope this helps :)