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Open Source Computer Vision Library
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73 lines
2.1 KiB
73 lines
2.1 KiB
''' |
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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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import numpy as np |
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import cv2 |
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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 = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) |
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eigen = cv2.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 = cv2.Sobel(gray, cv2.CV_32F, 2, 0, ksize=sigma) |
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gxy = cv2.Sobel(gray, cv2.CV_32F, 1, 1, ksize=sigma) |
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gyy = cv2.Sobel(gray, cv2.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 = cv2.erode(img, None) |
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dil = cv2.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: fn = sys.argv[1] |
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except: fn = '../cpp/baboon.jpg' |
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src = cv2.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 = cv2.getTrackbarPos('sigma', 'control')*2+1 |
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str_sigma = cv2.getTrackbarPos('str_sigma', 'control')*2+1 |
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blend = cv2.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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cv2.imshow('dst', dst) |
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cv2.namedWindow('control', 0) |
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cv2.createTrackbar('sigma', 'control', 9, 15, nothing) |
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cv2.createTrackbar('blend', 'control', 7, 10, nothing) |
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cv2.createTrackbar('str_sigma', 'control', 9, 15, nothing) |
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print 'Press SPACE to update the image\n' |
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cv2.imshow('src', src) |
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update() |
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while True: |
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ch = 0xFF & cv2.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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cv2.destroyAllWindows()
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