opencv/samples/python2/gabor_threads.py
2012-03-15 03:45:15 +00:00

69 lines
1.8 KiB
Python

'''
gabor_threads.py
=========
Sample demonstrates:
- use of multiple Gabor filter convolutions to get Fractalius-like image effect (http://www.redfieldplugins.com/filterFractalius.htm)
- use of python threading to accelerate the computation
Usage
-----
gabor_threads.py [image filename]
'''
import numpy as np
import cv2
from threading import Lock
from multiprocessing.pool import ThreadPool
def build_filters():
filters = []
ksize = 31
for theta in np.arange(0, np.pi, np.pi / 16):
kern = cv2.getGaborKernel((ksize, ksize), 4.0, theta, 10.0, 0.5, 0, ktype=cv2.CV_32F)
kern /= 1.5*kern.sum()
filters.append(kern)
return filters
def process(img, filters):
accum = np.zeros_like(img)
for kern in filters:
fimg = cv2.filter2D(img, cv2.CV_8UC3, kern)
np.maximum(accum, fimg, accum)
return accum
def process_threaded(img, filters, threadn = 8):
accum = np.zeros_like(img)
accum_lock = Lock()
def f(kern):
fimg = cv2.filter2D(img, cv2.CV_8UC3, kern)
with accum_lock:
np.maximum(accum, fimg, accum)
pool = ThreadPool(processes=threadn)
pool.map(f, filters)
return accum
if __name__ == '__main__':
import sys
from common import Timer
print __doc__
try: img_fn = sys.argv[1]
except: img_fn = '../cpp/baboon.jpg'
img = cv2.imread(img_fn)
filters = build_filters()
with Timer('running single-threaded'):
res1 = process(img, filters)
with Timer('running multi-threaded'):
res2 = process_threaded(img, filters)
print 'res1 == res2: ', (res1 == res2).all()
cv2.imshow('img', img)
cv2.imshow('result', res2)
cv2.waitKey()
cv2.destroyAllWindows()