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_dft.py

@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+
+'''
+Test for disctrete fourier transform (dft)
+'''
+
+# Python 2/3 compatibility
+from __future__ import print_function
+
+import cv2 as cv
+import numpy as np
+import sys
+
+from tests_common import NewOpenCVTests
+
+class dft_test(NewOpenCVTests):
+    def test_dft(self):
+
+        img = self.get_sample('samples/data/rubberwhale1.png', 0)
+        eps = 0.001
+
+        #test direct transform
+        refDft = np.fft.fft2(img)
+        refDftShift = np.fft.fftshift(refDft)
+        refMagnitide = np.log(1.0 + np.abs(refDftShift))
+
+        testDft = cv.dft(np.float32(img),flags = cv.DFT_COMPLEX_OUTPUT)
+        testDftShift = np.fft.fftshift(testDft)
+        testMagnitude = np.log(1.0 + cv.magnitude(testDftShift[:,:,0], testDftShift[:,:,1]))
+
+        refMagnitide = cv.normalize(refMagnitide, 0.0, 1.0, cv.NORM_MINMAX)
+        testMagnitude = cv.normalize(testMagnitude, 0.0, 1.0, cv.NORM_MINMAX)
+
+        self.assertLess(cv.norm(refMagnitide - testMagnitude), eps)
+
+        #test inverse transform
+        img_back = np.fft.ifft2(refDft)
+        img_back = np.abs(img_back)
+
+        img_backTest = cv.idft(testDft)
+        img_backTest = cv.magnitude(img_backTest[:,:,0], img_backTest[:,:,1])
+
+        img_backTest = cv.normalize(img_backTest, 0.0, 1.0, cv.NORM_MINMAX)
+        img_back = cv.normalize(img_back, 0.0, 1.0, cv.NORM_MINMAX)
+
+        self.assertLess(cv.norm(img_back - img_backTest), eps)
+
+
+if __name__ == '__main__':
+    NewOpenCVTests.bootstrap()