1 #!/usr/bin/env python 2 3 ''' An example of Laplacian Pyramid construction and merging. 4 5 Level : Intermediate 6 7 Usage : python lappyr.py [<video source>] 8 9 References: 10 http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.54.299 11 12 Alexander Mordvintsev 6/10/12 13 ''' 14 15 import numpy as np 16 import cv2 17 import video 18 from common import nothing, getsize 19 20 def build_lappyr(img, leveln=6, dtype=np.int16): 21 img = dtype(img) 22 levels = [] 23 for i in xrange(leveln-1): 24 next_img = cv2.pyrDown(img) 25 img1 = cv2.pyrUp(next_img, dstsize=getsize(img)) 26 levels.append(img-img1) 27 img = next_img 28 levels.append(img) 29 return levels 30 31 def merge_lappyr(levels): 32 img = levels[-1] 33 for lev_img in levels[-2::-1]: 34 img = cv2.pyrUp(img, dstsize=getsize(lev_img)) 35 img += lev_img 36 return np.uint8(np.clip(img, 0, 255)) 37 38 39 if __name__ == '__main__': 40 import sys 41 print __doc__ 42 43 try: 44 fn = sys.argv[1] 45 except: 46 fn = 0 47 cap = video.create_capture(fn) 48 49 leveln = 6 50 cv2.namedWindow('level control') 51 for i in xrange(leveln): 52 cv2.createTrackbar('%d'%i, 'level control', 5, 50, nothing) 53 54 while True: 55 ret, frame = cap.read() 56 57 pyr = build_lappyr(frame, leveln) 58 for i in xrange(leveln): 59 v = cv2.getTrackbarPos('%d'%i, 'level control') / 5 60 pyr[i] *= v 61 res = merge_lappyr(pyr) 62 63 cv2.imshow('laplacian pyramid filter', res) 64 65 if cv2.waitKey(1) & 0xFF == 27: 66 break 67
