Pytesseract image_to_data not able to read the numbers in my image

Issue

So I’m currently working on a project where I use pyautogui and pytesseract to take a screenshot of the time in a video game emulator I’m using, and then to try and read the image and determine what time I got. Here’s what the image looks like when I use pyautogui to get the screenshot of the region I want:

in game timer

Simply just using pytesseract.image_to_string() worked with images of text when I tested it out to make sure it was installed properly, but when I use the in game timer picture it doesn’t output anything. Does this have to do with the quality of the image or some imitation with pytesseract or what?

Solution

You need to preprocess the image before performing OCR with Pytesseract. Here’s a simple approach using OpenCV and Pytesseract OCR. The idea is to obtain a processed image where the text to extract is in black with the background in white. To do this, we can convert to grayscale, apply a slight Gaussian blur, then Otsu’s threshold to obtain a binary image. We perform text extraction using the --psm 6 configuration option to assume a single uniform block of text. Take a look here for more options.


Input image

enter image description here

Otsu’s threshold to get a binary image

enter image description here

Result from Pytesseract OCR

0’ 12”92

Code

import cv2
import pytesseract

pytesseract.pytesseract.tesseract_cmd = r"C:\Program Files\Tesseract-OCR\tesseract.exe"

# Grayscale, Gaussian blur, Otsu's threshold
image = cv2.imread('1.png')
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray, (3,3), 0)
thresh = cv2.threshold(blur, 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)[1]

# Perform text extraction
data = pytesseract.image_to_string(thresh, lang='eng', config='--psm 6')
print(data)

cv2.imshow('thresh', thresh)
cv2.waitKey()

Answered By – nathancy

Answer Checked By – Robin (AngularFixing Admin)

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