试图找到发票/收据扫描图像的旋转角度，然后将其旋转到正确位置

Question

Hi Iam trying to find the angle by which the scanned receipt or invoices are aligned and then getting it to the correct position....enter image description here图片说明：I want to find the angle of these two king of non line images angle of rotation please help

enter code here

import cv2`enter code here`
import numpy as np
import glob

def detect_angle(image):
    mask = np.zeros(image.shape, dtype=np.uint8)
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    blur = cv2.GaussianBlur(gray, (3,3), 0)
    adaptive = cv2.adaptiveThreshold(blur,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY_INV,15,4)

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

    for c in cnts:
        area = cv2.contourArea(c)
        if area < 45000 and area > 20:
            cv2.drawContours(mask, [c], -1, (255,255,255), -1)

    mask = cv2.cvtColor(mask, cv2.COLOR_BGR2GRAY)
    h, w = mask.shape

    # Horizontal
    if w > h:
        left = mask[0:h, 0:0+w//2]
        right = mask[0:h, w//2:]
        left_pixels = cv2.countNonZero(left)
        right_pixels = cv2.countNonZero(right)
        return 0 if left_pixels >= right_pixels else 180
    # Vertical
    else:
        top = mask[0:h//2, 0:w]
        bottom = mask[h//2:, 0:w]
        top_pixels = cv2.countNonZero(top)
        bottom_pixels = cv2.countNonZero(bottom)
        return 90 if bottom_pixels >= top_pixels else 270

if __name__ == '__main__':
    filenames = [img for img in glob.glob(r"C:\Users\lenovo\Desktop\samples\images for oPEN CV/*.png")]

    filenames.sort() # ADD THIS LINE

    images = []
    for img in filenames:
        n= cv2.imread(img)
        images.append(n)
        print (img)
        image = cv2.imread(img)
        angle = detect_angle(image)
        print(angle)