NotePad1.1.py

import cv2
import numpy as np

def crop():
    img = cv2.imread("Images/20230218_081138.jpg")

    gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    blur = cv2.medianBlur(gray, 5)

    thresh = cv2.adaptiveThreshold(blur,255,cv2.ADAPTIVE_THRESH_MEAN_C,cv2.THRESH_BINARY,11,2)
    kernel = np.ones((5,5),np.uint8)
    errosion = cv2.erode(thresh,kernel,iterations=1)

    kernel2 = cv2.getStructuringElement(cv2.MORPH_RECT, (2,2))
    dilate = cv2.dilate(errosion, kernel2, iterations=3)
    cnts = cv2.findContours(dilate, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    cnts = cnts[0] if len(cnts) == 2 else cnts[1]

    cnts = sorted(cnts, key=cv2.contourArea, reverse=True)

    #for c in cnts:
    x,y,w,h = cv2.boundingRect(cnts[0])
    ROI = img[y:y+h, x:x+w]
    #break

    cv2.drawContours(dilate, cnts, -1, (0, 255, 0), 3)
    cv2.namedWindow('ROI', cv2.WINDOW_NORMAL)
    cv2.imshow("ROI",ROI)

    return ROI

def extractText(img):
    hsv = cv2.cvtColor(img,cv2.COLOR_BGR2HSV)
    
    lower_blue = np.array([20,50,50])
    upper_blue = np.array([110,255,255])
    mask = cv2.inRange(hsv,lower_blue,upper_blue)

    th2 = cv2.adaptiveThreshold(mask,255,cv2.ADAPTIVE_THRESH_MEAN_C,cv2.THRESH_BINARY,11,2)
    kernel = np.ones((5,5),np.uint8)
    errosion = cv2.erode(mask,kernel,iterations=1)

    opening = cv2.morphologyEx(errosion, cv2.MORPH_OPEN, kernel)

    cnts = cv2.findContours(errosion, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    cnts = cnts[0] if len(cnts) == 2 else cnts[1]

    cnts = sorted(cnts, key=cv2.contourArea, reverse=True)
    img2 = np.full(img.shape,255, np.uint8)
    #print(cnts[1].shape,img.shape)
    cv2.drawContours(img2, cnts, -1, (0, 0, 0), -1)

    cv2.namedWindow('image', cv2.WINDOW_NORMAL)
    cv2.imshow("image",img2)
    cv2.imwrite('note.png', img2)

def main():
    print("NotePad 1.1")
    ROI = crop()
    extractText(ROI)
    cv2.waitKey(0)
    cv2.destroyAllWindows()

if __name__ == '__main__':
    main()