def threshold_image(image, n=[]):
"""Record the first 5 images to get a background, then diff current frame with the last saved frame.
"""
if len(n) < 5:
# n[4] will be our background
# First capture a few images
n.append(cv.cvCloneMat(image))
if len(n) == 5:
# last time here
# could do averaging here.
pass
return image
original = n[4]
differenceImage = cv.cvCloneMat( image )
cv.cvAbsDiff( image, original, differenceImage )
"""The threshold value determines the amount of "Change" required
before something will show up"""
thresholdValue = 50 # 32
cv.cvThreshold( differenceImage, differenceImage, thresholdValue, 255, cv.CV_THRESH_BINARY )
# Convert to one channel
gray = cv.cvCreateImage( cv.cvGetSize(differenceImage), 8, 1 )
cv.cvCvtColor( differenceImage, gray, cv.CV_BGR2GRAY )
# Use median filter to remove salt and pepper noise.
cv.cvSmooth(gray, gray, cv.CV_MEDIAN, 15)
# Dilate and the threshold image
# It adds a border to the object.
#cv.cvDilate(gray,gray, None, 9)
# Add a bit of Blur to the threshold mask
cv.cvSmooth(gray, gray, cv.CV_GAUSSIAN, 5)
result = cv.cvCloneMat( image)
cv.cvSetZero(result)
cv.cvAnd(image,image, result, gray)
return result
def process(self, take_new_image=True):
"""We will take a snapshot, optionally do some arbitrary process (eg in numpy/scipy)
then display it. If a frame is given use that instead of taking a new image.
"""
try:
if take_new_image:
logging.debug("capturing an image")
self.snapshot = cv.cvCloneMat( hg.cvQueryFrame( self.camera) )
if self.processFunction is not None:
logging.debug("Sending image to process function")
res = self.processFunction(self.snapshot)
logging.debug("Received result from processing function")
assert isinstance(res,cv.CvMat), "Not CvMat"
self.snapshot = res
if self.show:
hg.cvShowImage( self.title, self.snapshot )
except Exception, e:
# If something goes wrong make sure we close the window
logging.error("Error in processing image: %s" % e)
hg.cvDestroyWindow(self.title)
raise SystemExit
def __init__(self, processFunction = None, title = "Video Capture Player", show=True, **argd):
self.__dict__.update(**argd)
super(VideoCapturePlayer, self).__init__(**argd)
t_begin = time.time()
self.processFunction = processFunction
self.title = title
self.show = show
if self.show is True:
self.display = hg.cvNamedWindow(self.title)
try:
self.camera = hg.cvCreateCameraCapture(0)
# Take a frame to get props and use in testing
self.snapshot = cv.cvCloneMat( hg.cvQueryFrame( self.camera ) )
# check that we got an image, otherwise try again.
for i in xrange(20):
if self.snapshot is not None: break
self.snapshot = hg.cvQueryFrame( self.camera )
except:
print("Couldn't open camera device, is it connected?")
hg.cvDestroyWindow(title)
raise SystemExit
def process(self, take_new_image=True):
"""We will take a snapshot, optionally do some arbitrary process (eg in numpy/scipy)
then display it. If a frame is given use that instead of taking a new image.
"""
try:
if take_new_image:
logging.debug("capturing an image")
self.snapshot = cv.cvCloneMat(hg.cvQueryFrame(self.camera))
if self.processFunction is not None:
logging.debug("Sending image to process function")
res = self.processFunction(self.snapshot)
logging.debug("Received result from processing function")
assert isinstance(res, cv.CvMat), "Not CvMat"
self.snapshot = res
if self.show:
hg.cvShowImage(self.title, self.snapshot)
except Exception, e:
# If something goes wrong make sure we close the window
logging.error("Error in processing image: %s" % e)
hg.cvDestroyWindow(self.title)
raise SystemExit
