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/samples/python/lk_homography.py

@@ -0,0 +1,123 @@
+#!/usr/bin/env python
+
+'''
+Lucas-Kanade homography tracker
+===============================
+
+Lucas-Kanade sparse optical flow demo. Uses goodFeaturesToTrack
+for track initialization and back-tracking for match verification
+between frames. Finds homography between reference and current views.
+
+Usage
+-----
+lk_homography.py [<video_source>]
+
+
+Keys
+----
+ESC   - exit
+SPACE - start tracking
+r     - toggle RANSAC
+'''
+
+# Python 2/3 compatibility
+from __future__ import print_function
+
+import numpy as np
+import cv2 as cv
+
+import video
+from common import draw_str
+from video import presets
+
+lk_params = dict( winSize  = (19, 19),
+                  maxLevel = 2,
+                  criteria = (cv.TERM_CRITERIA_EPS | cv.TERM_CRITERIA_COUNT, 10, 0.03))
+
+feature_params = dict( maxCorners = 1000,
+                       qualityLevel = 0.01,
+                       minDistance = 8,
+                       blockSize = 19 )
+
+def checkedTrace(img0, img1, p0, back_threshold = 1.0):
+    p1, _st, _err = cv.calcOpticalFlowPyrLK(img0, img1, p0, None, **lk_params)
+    p0r, _st, _err = cv.calcOpticalFlowPyrLK(img1, img0, p1, None, **lk_params)
+    d = abs(p0-p0r).reshape(-1, 2).max(-1)
+    status = d < back_threshold
+    return p1, status
+
+green = (0, 255, 0)
+red = (0, 0, 255)
+
+class App:
+    def __init__(self, video_src):
+        self.cam = self.cam = video.create_capture(video_src, presets['book'])
+        self.p0 = None
+        self.use_ransac = True
+
+    def run(self):
+        while True:
+            _ret, frame = self.cam.read()
+            frame_gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
+            vis = frame.copy()
+            if self.p0 is not None:
+                p2, trace_status = checkedTrace(self.gray1, frame_gray, self.p1)
+
+                self.p1 = p2[trace_status].copy()
+                self.p0 = self.p0[trace_status].copy()
+                self.gray1 = frame_gray
+
+                if len(self.p0) < 4:
+                    self.p0 = None
+                    continue
+                H, status = cv.findHomography(self.p0, self.p1, (0, cv.RANSAC)[self.use_ransac], 10.0)
+                h, w = frame.shape[:2]
+                overlay = cv.warpPerspective(self.frame0, H, (w, h))
+                vis = cv.addWeighted(vis, 0.5, overlay, 0.5, 0.0)
+
+                for (x0, y0), (x1, y1), good in zip(self.p0[:,0], self.p1[:,0], status[:,0]):
+                    if good:
+                        cv.line(vis, (int(x0), int(y0)), (int(x1), int(y1)), (0, 128, 0))
+                    cv.circle(vis, (int(x1), int(y1)), 2, (red, green)[good], -1)
+                draw_str(vis, (20, 20), 'track count: %d' % len(self.p1))
+                if self.use_ransac:
+                    draw_str(vis, (20, 40), 'RANSAC')
+            else:
+                p = cv.goodFeaturesToTrack(frame_gray, **feature_params)
+                if p is not None:
+                    for x, y in p[:,0]:
+                        cv.circle(vis, (int(x), int(y)), 2, green, -1)
+                    draw_str(vis, (20, 20), 'feature count: %d' % len(p))
+
+            cv.imshow('lk_homography', vis)
+
+            ch = cv.waitKey(1)
+            if ch == 27:
+                break
+            if ch == ord(' '):
+                self.frame0 = frame.copy()
+                self.p0 = cv.goodFeaturesToTrack(frame_gray, **feature_params)
+                if self.p0 is not None:
+                    self.p1 = self.p0
+                    self.gray0 = frame_gray
+                    self.gray1 = frame_gray
+            if ch == ord('r'):
+                self.use_ransac = not self.use_ransac
+
+
+
+def main():
+    import sys
+    try:
+        video_src = sys.argv[1]
+    except:
+        video_src = 0
+
+    App(video_src).run()
+    print('Done')
+
+
+if __name__ == '__main__':
+    print(__doc__)
+    main()
+    cv.destroyAllWindows()