How can i extract numbers colored green in image using Python-CodePudding

There will be a picture, in the picture there are 3 numbers of indefinite length. The correct one is colored green. I want to print the green colored number.

example image

my code

  img = cv2.imread("image.png")
  img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

  img = cv2.bitwise_not(img)
  _, binary = cv2.threshold(img, 0, 255, cv2.THRESH_BINARY)
  txt = pytesseract.image_to_string(binary, config="--oem 3 --psm 4")
  print(txt)

CodePudding user response：

When you import the image with cv2.COLOR_BGR2GRAY, you are telling it to delete all color information, and convert to grayscale.

This code gets the image you posted, and converts to RGB with cv2.COLOR_BGR2RGB

The image is an array with format image[row, column, [red,green,blue] ]

Now you can extract the green color, and OCR it with Tesseract (you have to had Tesseract installed, and also the Python library pytesseract)

import numpy as np
import cv2
import matplotlib.pyplot as plt


def downloadImage(URL):
    """Downloads the image on the URL, and convers to cv2 BGR format"""
    from io import BytesIO
    from PIL import Image as PIL_Image
    import requests

    response = requests.get(URL)
    image = PIL_Image.open(BytesIO(response.content))
    return cv2.cvtColor(np.array(image), cv2.COLOR_BGR2RGB)


URL = "https://i.stack.imgur.com/tYTZ8.png"

# Read image
colorImage = downloadImage(URL)

RED, GREEN, BLUE = 0, 1, 2
# Filter image with much of GREEN, and little of RED and BLUE
greenImage = (
      (colorImage[:, :, RED] < 50)
    & (colorImage[:, :, GREEN] > 100)
    & (colorImage[:, :, BLUE] < 50)
)

plt.imshow(greenImage)
plt.show()

import pytesseract as pt

txt = pt.image_to_string(greenImage, config="--oem 3 --psm 4")
print(txt)
>>>107018