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85 lines
2.2 KiB
85 lines
2.2 KiB
#!/usr/bin/env python |
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''' |
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Coherence-enhancing filtering example |
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===================================== |
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inspired by |
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Joachim Weickert "Coherence-Enhancing Shock Filters" |
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http://www.mia.uni-saarland.de/Publications/weickert-dagm03.pdf |
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''' |
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# Python 2/3 compatibility |
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from __future__ import print_function |
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import sys |
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PY3 = sys.version_info[0] == 3 |
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if PY3: |
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xrange = range |
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import numpy as np |
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import cv2 as cv |
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def coherence_filter(img, sigma = 11, str_sigma = 11, blend = 0.5, iter_n = 4): |
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h, w = img.shape[:2] |
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for i in xrange(iter_n): |
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print(i) |
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gray = cv.cvtColor(img, cv.COLOR_BGR2GRAY) |
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eigen = cv.cornerEigenValsAndVecs(gray, str_sigma, 3) |
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eigen = eigen.reshape(h, w, 3, 2) # [[e1, e2], v1, v2] |
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x, y = eigen[:,:,1,0], eigen[:,:,1,1] |
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gxx = cv.Sobel(gray, cv.CV_32F, 2, 0, ksize=sigma) |
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gxy = cv.Sobel(gray, cv.CV_32F, 1, 1, ksize=sigma) |
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gyy = cv.Sobel(gray, cv.CV_32F, 0, 2, ksize=sigma) |
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gvv = x*x*gxx + 2*x*y*gxy + y*y*gyy |
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m = gvv < 0 |
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ero = cv.erode(img, None) |
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dil = cv.dilate(img, None) |
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img1 = ero |
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img1[m] = dil[m] |
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img = np.uint8(img*(1.0 - blend) + img1*blend) |
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print('done') |
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return img |
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if __name__ == '__main__': |
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import sys |
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try: |
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fn = sys.argv[1] |
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except: |
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fn = '../data/baboon.jpg' |
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src = cv.imread(fn) |
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def nothing(*argv): |
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pass |
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def update(): |
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sigma = cv.getTrackbarPos('sigma', 'control')*2+1 |
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str_sigma = cv.getTrackbarPos('str_sigma', 'control')*2+1 |
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blend = cv.getTrackbarPos('blend', 'control') / 10.0 |
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print('sigma: %d str_sigma: %d blend_coef: %f' % (sigma, str_sigma, blend)) |
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dst = coherence_filter(src, sigma=sigma, str_sigma = str_sigma, blend = blend) |
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cv.imshow('dst', dst) |
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cv.namedWindow('control', 0) |
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cv.createTrackbar('sigma', 'control', 9, 15, nothing) |
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cv.createTrackbar('blend', 'control', 7, 10, nothing) |
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cv.createTrackbar('str_sigma', 'control', 9, 15, nothing) |
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print('Press SPACE to update the image\n') |
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cv.imshow('src', src) |
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update() |
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while True: |
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ch = cv.waitKey() |
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if ch == ord(' '): |
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update() |
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if ch == 27: |
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break |
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cv.destroyAllWindows()
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