Edge Detection Comparison

1
Edge Detection Comparison

• Team Orange Project Presentation
• Ryan Bolt
• Bruce Johnson
• Murali Uppala
• Brian Sharp

2
Edge Detectors Considered

• Sobel
• Prewitt
• Laplace

3
Sobel

• Applies a 3x3 convolution filter row-wise in
  order to determine the gradient of the
  surrounding pixels.
• Pixel is a member of an edge if the intensity of
  it is greater than that of the members of its
  surrounding pixels.

4
Prewitt

• This is similar to the Sobel detector
• Operates under the same principle except that it
  uses a different (simpler) convolution kernel.

5
Laplace

• Applies one (x direction or y direction) 3x3
  convolution filter to a pixel in order to
  determine the gradient of the surrounding pixels.
• Pixel is a member of an edge if the intensity of
  it is increasing faster than that of the members
  of its surrounding pixels.

6
MATLAB Testing
7
Laplace MATLAB Results
8
Sobel MATLAB Results
9
Prewitt MATLAB Results
10
DATA FLOW
11
Design Flow
12
VHDL Flow Chart
13
Simulation Reading Pixels in
14
Simulation Calculating 1 Output Pixel
15
Writing Back to Memory Simulation
16
Xilinx Floorplan
17
Resources Used

• Number of BUFGMUXs 6 out of 16
  37
• Number of DCMs 2 out of 8
  25
• Number of External IOBs 13 out of 556
  2
• Number of LOCed IOBs 13 out of 13
  100
• Number of JTAGPPCs 1 out of 1
  100
• Number of PPC405s 2 out of 2
  100
• Number of RAMB16s 56 out of 136
  41
• Number of SLICEs 2159 out of
  13696 15

18
Initial Results
19
Works Cited

• 1. Snyder, W. E., Qi, H. Machine Vision,
  Cambridge University Press, 2004.
• 2.http//fourier.eng.hmc.edu/e161/lectures/gradien
  t/node8.html