feat: 切换后端至PaddleOCR-NCNN，切换工程为CMake

1.项目后端整体迁移至PaddleOCR-NCNN算法，已通过基本的兼容性测试
2.工程改为使用CMake组织，后续为了更好地兼容第三方库，不再提供QMake工程
3.重整权利声明文件，重整代码工程，确保最小化侵权风险

Log: 切换后端至PaddleOCR-NCNN，切换工程为CMake
Change-Id: I4d5d2c5d37505a4a24b389b1a4c5d12f17bfa38c

3rdparty/opencv-4.5.4/modules/python/test/test_squares.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+
+'''
+Simple "Square Detector" program.
+
+Loads several images sequentially and tries to find squares in each image.
+'''
+
+# Python 2/3 compatibility
+import sys
+PY3 = sys.version_info[0] == 3
+
+if PY3:
+    xrange = range
+
+import numpy as np
+import cv2 as cv
+
+
+def angle_cos(p0, p1, p2):
+    d1, d2 = (p0-p1).astype('float'), (p2-p1).astype('float')
+    return abs( np.dot(d1, d2) / np.sqrt( np.dot(d1, d1)*np.dot(d2, d2) ) )
+
+def find_squares(img):
+    img = cv.GaussianBlur(img, (5, 5), 0)
+    squares = []
+    for gray in cv.split(img):
+        for thrs in xrange(0, 255, 26):
+            if thrs == 0:
+                bin = cv.Canny(gray, 0, 50, apertureSize=5)
+                bin = cv.dilate(bin, None)
+            else:
+                _retval, bin = cv.threshold(gray, thrs, 255, cv.THRESH_BINARY)
+            contours, _hierarchy = cv.findContours(bin, cv.RETR_LIST, cv.CHAIN_APPROX_SIMPLE)
+            for cnt in contours:
+                cnt_len = cv.arcLength(cnt, True)
+                cnt = cv.approxPolyDP(cnt, 0.02*cnt_len, True)
+                if len(cnt) == 4 and cv.contourArea(cnt) > 1000 and cv.isContourConvex(cnt):
+                    cnt = cnt.reshape(-1, 2)
+                    max_cos = np.max([angle_cos( cnt[i], cnt[(i+1) % 4], cnt[(i+2) % 4] ) for i in xrange(4)])
+                    if max_cos < 0.1 and filterSquares(squares, cnt):
+                        squares.append(cnt)
+
+    return squares
+
+def intersectionRate(s1, s2):
+    area, _intersection = cv.intersectConvexConvex(np.array(s1), np.array(s2))
+    return 2 * area / (cv.contourArea(np.array(s1)) + cv.contourArea(np.array(s2)))
+
+def filterSquares(squares, square):
+
+    for i in range(len(squares)):
+        if intersectionRate(squares[i], square) > 0.95:
+            return False
+
+    return True
+
+from tests_common import NewOpenCVTests
+
+class squares_test(NewOpenCVTests):
+
+    def test_squares(self):
+
+        img = self.get_sample('samples/data/pic1.png')
+        squares = find_squares(img)
+
+        testSquares = [
+        [[43, 25],
+        [43, 129],
+        [232, 129],
+        [232, 25]],
+
+        [[252, 87],
+        [324, 40],
+        [387, 137],
+        [315, 184]],
+
+        [[154, 178],
+        [196, 180],
+        [198, 278],
+        [154, 278]],
+
+        [[0, 0],
+        [400, 0],
+        [400, 300],
+        [0, 300]]
+        ]
+
+        matches_counter = 0
+        for i in range(len(squares)):
+            for j in range(len(testSquares)):
+                if intersectionRate(squares[i], testSquares[j]) > 0.9:
+                    matches_counter += 1
+
+        self.assertGreater(matches_counter / len(testSquares), 0.9)
+        self.assertLess( (len(squares) - matches_counter) / len(squares), 0.2)
+
+if __name__ == '__main__':
+    NewOpenCVTests.bootstrap()