56 lines
1.8 KiB
Python
56 lines
1.8 KiB
Python
#!/usr/bin/env python
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from cv import *
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class FBackDemo:
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def __init__(self):
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self.capture = CaptureFromCAM(0)
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self.mv_step = 16
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self.mv_scale = 1.5
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self.mv_color = (0, 255, 0)
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self.cflow = None
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self.flow = None
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NamedWindow( "Optical Flow", 1 )
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print( "Press ESC - quit the program\n" )
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def draw_flow(self, flow, prevgray):
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""" Returns a nice representation of a hue histogram """
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CvtColor(prevgray, self.cflow, CV_GRAY2BGR)
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for y in range(0, flow.height, self.mv_step):
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for x in range(0, flow.width, self.mv_step):
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fx, fy = flow[y, x]
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Line(self.cflow, (x,y), (x+fx,y+fy), self.mv_color)
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Circle(self.cflow, (x,y), 2, self.mv_color, -1)
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ShowImage("Optical Flow", self.cflow)
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def run(self):
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first_frame = True
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while True:
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frame = QueryFrame( self.capture )
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if first_frame:
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gray = CreateImage(GetSize(frame), 8, 1)
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prev_gray = CreateImage(GetSize(frame), 8, 1)
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flow = CreateImage(GetSize(frame), 32, 2)
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self.cflow = CreateImage(GetSize(frame), 8, 3)
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CvtColor(frame, gray, CV_BGR2GRAY)
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if not first_frame:
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CalcOpticalFlowFarneback(prev_gray, gray, flow,
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pyr_scale=0.5, levels=3, winsize=15,
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iterations=3, poly_n=5, poly_sigma=1.2, flags=0)
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self.draw_flow(flow, prev_gray)
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c = WaitKey(7)
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if c in [27, ord('q'), ord('Q')]:
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break
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prev_gray, gray = gray, prev_gray
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first_frame = False
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if __name__=="__main__":
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demo = FBackDemo()
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demo.run()
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