Smoothing%20the%20intensities

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Smoothing the intensities
Intensity
Smoothing
More Smoothing
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Intensity Derivative
Smoothed Intensity
First Derivative
Second Derivative
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The Derivative of a Convolution
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Analyzing a 2D image
Image after smoothing and second derivative
Image
Black Negative White Positive
Zero-Crossings
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Smoothing a 2D Image
To smooth an image, I(x,y), we can convolve with
a 2D Gaussian
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Differentiation in 2D
To differentiate the smoothed 2D image, we will
use the Laplacian operator

We can again combine the smoothing and derivative
operations
(displayed with sign reversed)
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Detecting intensity changes at multiple scales

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Computing the contrast of intensity changes


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The Eye
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The Neuron

• Major parts of a neuron
• Cell body
• Axon
• Terminal
• Synaptic cleft
• Dendrites

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Projection from the Retina
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Retinal Ganglion Cells
Retinal Ganglion cells have receptive fields that
exhibit a center-surround structure.