mirror of
https://github.com/opencv/opencv.git
synced 2024-12-26 02:28:04 +08:00
48 lines
1.1 KiB
Python
Executable File
48 lines
1.1 KiB
Python
Executable File
#!/usr/bin/env python
|
|
|
|
'''
|
|
Texture flow direction estimation.
|
|
|
|
Sample shows how cv2.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
|
|
|
|
if __name__ == '__main__':
|
|
import sys
|
|
try:
|
|
fn = sys.argv[1]
|
|
except:
|
|
fn = '../data/starry_night.jpg'
|
|
|
|
img = cv2.imread(fn)
|
|
if img is None:
|
|
print('Failed to load image file:', fn)
|
|
sys.exit(1)
|
|
|
|
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
|
|
h, w = img.shape[:2]
|
|
|
|
eigen = cv2.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)
|
|
cv2.line(vis, (x-vx, y-vy), (x+vx, y+vy), (0, 0, 0), 1, cv2.LINE_AA)
|
|
cv2.imshow('input', img)
|
|
cv2.imshow('flow', vis)
|
|
cv2.waitKey()
|