init - 初始化项目

samples/python/texture_flow.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+
+'''
+Texture flow direction estimation.
+
+Sample shows how cv.cornerEigenValsAndVecs function can be used
+to estimate image texture flow direction.
+
+Usage:
+    texture_flow.py [<image>]
+'''
+
+# Python 2/3 compatibility
+from __future__ import print_function
+
+import numpy as np
+import cv2 as cv
+
+def main():
+    import sys
+    try:
+        fn = sys.argv[1]
+    except:
+        fn = 'starry_night.jpg'
+
+    img = cv.imread(cv.samples.findFile(fn))
+    if img is None:
+        print('Failed to load image file:', fn)
+        sys.exit(1)
+
+    gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY)
+    h, w = img.shape[:2]
+
+    eigen = cv.cornerEigenValsAndVecs(gray, 15, 3)
+    eigen = eigen.reshape(h, w, 3, 2)  # [[e1, e2], v1, v2]
+    flow = eigen[:,:,2]
+
+    vis = img.copy()
+    vis[:] = (192 + np.uint32(vis)) / 2
+    d = 12
+    points =  np.dstack( np.mgrid[d/2:w:d, d/2:h:d] ).reshape(-1, 2)
+    for x, y in np.int32(points):
+        vx, vy = np.int32(flow[y, x]*d)
+        cv.line(vis, (x-vx, y-vy), (x+vx, y+vy), (0, 0, 0), 1, cv.LINE_AA)
+    cv.imshow('input', img)
+    cv.imshow('flow', vis)
+    cv.waitKey()
+
+    print('Done')
+
+
+if __name__ == '__main__':
+    print(__doc__)
+    main()
+    cv.destroyAllWindows()