Function File: [r, c] = immaximas (im, radius)
Function File: [r, c] = immaximas (im, radius, thresh)
Function File: [r, c, …] = immaximas (…)
Function File: […, val] = immaximas (…)

Find local spatial maximas.

Local spatial maximas should not be mistaken with regional maxima. See imregionalmax for the later.

A local spatial maxima is defined as an image point with a value that is larger than all neighbouring values in a square region of width 2*radius+1. By default radius is 1, such that a 3 by 3 neighbourhood is searched. If the thresh input argument is supplied, only local maximas with a value greater than thresh are retained.

The output vectors r and c contain the row-column coordinates of the local maximas. The actual values are computed to sub-pixel precision by fitting a parabola to the data around the pixel. If im is N-dimensional, then N vectors will be returned.

If im is N-dimensional, and N+1 outputs are requested, then the last output will contain the image values at the maximas. Currently this value is not interpolated.

See also: imregionalmax, ordfilt2, ordfiltn.

Package: image