Edge DetectionCompression and Security of Surveillance Videos張晏豪

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Experimental Setting Windows XPIntel(R) Core(TM)2 Quad CPU

Q6600 @2.40GHz2GB RAM

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Experimental ParametersThreshold_sobel:Determine how many

edge points you wantThreshold_dis: If the point is in the

interval (- Threshold_dis,+ Threshold_dis), the point is regarded as edge point

Threshold_score: If the amount of edge points around the line are more than threshold_score, the line is regard as true line

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Experimental Results Edge points: Original image after Sobel filter Threshold_sobel:130 2949 edge points 4346826 lines

Original image Edge points

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Experimental Results Threshold_sobel:130 Threshold_dis:5 Threshold_score:400 Elapsed time :4738 sec

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Threshold_sobel:130Threshold_dis:1.5Threshold_score:200

Threshold_sobel:130Threshold_dis:1.5Threshold_score:50

Threshold_sobel:130Threshold_dis:1.5Threshold_score:150

Threshold_sobel:130Threshold_dis:1.5Threshold_score:100

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Experimental Results Threshold_sobel:130 Threshold_dis:1.5 Threshold_score:100 Elapsed time:4982 sec

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Paint the lines with top 1000 score

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Hough TransformDetect lines in r-θ plane

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Experimental ParametersThreshold_sobel: Determine how

many edge points you wantThreshold_interval: Angle

increment of each detectionThreshold_votes: If the amount of

edge points on the angle are more than threshold_score, the line at this angle would be painted

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Experimental Results

Threshold_sobel:130Threshold_interval:1Threshold_votes:10

Threshold_sobel:130Threshold_interval:1Threshold_votes:20

Threshold_sobel:130Threshold_interval:1Threshold_votes:5

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Experimental Results Threshold_sobel:130 Edge points:2949 Threshold_interval:1 Threshold_votes:10 Elapsed time :0.87 sec

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Experimental Results

Threshold_sobel:130Threshold_interval:1Threshold_votes:5

Threshold_sobel:130Threshold_interval:1Threshold_votes:10

Threshold_sobel:130Threshold_interval:1Threshold_votes:15

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Experimental Results Threshold_sobel:130 Edge points:4866 Threshold_interval:1 Threshold_votes:10 Elapsed time :1.37 sec

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