HARRIS_CORNER_DETECTOR

Name

Purpose

This function will find corners in an image. Corners are defined
in this context as localized areas within the image were small
shifts in the image in any direction produce a significant
change in the composition of the neighborhood.

Calling Sequence

Result = $
HARRIS_CORNER_DETECTOR( image, $
sigma, $
metric, $
OVERLAY=overlay, $
DEBUG=debug )

Return Value

This function will return a 2xN array of coordinates indicating
corner locations found throughout the provided image.

Inputs

image
An array containing the data within which corners are to be
located.
sigma
A scalar defining the standard deviation of the gaussian
blurring kernel to be used in the smoothing/averaging operation
used to reduce noise in the intermediate gradient images. This
quantity is defined in units of pixels. [DEFAULT=1]
metric
A flag indicating which response surface metric is to be
used. The metrics are defined as
1 - lambda2
2 - (lambda1 * lambda2) / (lambda1 + lambda2)
3 - (lambda1 * lambda2) - (lambda1 + lambda2)
4 - (lambda1 * lambda2) - k*(lambda1 + lambda2)^2 [DEFAULT]

Keyword Parameters

OVERLAY=overlay
Indicates a copy of the original image provided is to be returned
in a 3-band color image format with red pixels indicating where
the corners found were located.
DEBUG=debug
Indicates that debug images/results should be produced at run time
if set.

Return Value

This function returns a 2xn array containing the image coordinates of the
n corner points identified by the FAST detector.

Side Effects

None

Requires

FIND_CLUSTER_CENTERS

Reference

Harris, C. and M.J. Stephens, A combined corner and edge detector,
Alvey Vision Converence, 1988, pp. 147-152

Side Effects

None

Modification History

Written by: Carl Salvaggio
September, 2008 Original Code
April, 2012 Added debug keyword todisplay intermediate results

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