SPECTRAL_FEATURES_CVIP

spectral_features_cvip() - extracts spectral features based on Fourier transform ,ring and sector power.

SYNTAX
DESCRIPTION
REFERENCE
EXAMPLE
CREDITS

SYNTAX

out_feat = spectral_features_cvip( input_img,mask_img, objLabel, spec_feat )

Input Parameters include :

input_img - The orignial image which can be grayscale or RGB.

mask_img - Label image of MxN size with single object or multiple objects. Each object has unique gray value.
objLabel - Labels of the objects. Column vector (Yx1) or Yx2 matrix. If row vector, objLabel must be unique gray value corresponding to each object. If Yx2 matrix, objLabel must have row index in first column and col index in second column for each object.
spec_feat - a Row vector of size 1x2 with which its first element determines the number of rings and the 2nd element determines the number of sectors.If empty, the default values are [3 3].

Output Parameter include :

out_feat - Cell array containing object name,object label,and feature values for selected features.

DESCRIPTION

This function calculates the spectral features of an object, given as input by the user, based on the spectral features selected by the user. The spectral features measure the power in the Fourier spectrum of the binary object. Due to the redundancy in the Fourier spectral symmetry, the sector power features are often measured over one-half of the spectrum and the ring power features are measured over the other half of the spectrum.

REFERENCE

1. Scott E Umbaugh. DIGITAL IMAGE PROCESSING AND ANALYSIS: Applications with MATLAB and CVIPtools, 3rd Edition.

EXAMPLE

% Read image

 input_img = imread('Stripey.jpg');

% Mask image

 mask_img = zeros(size(input_img));

 mask_img = mask_img(:,:,1);

 mask_img(50:200,25:95) = 1;

 mask_img(100:300,255:400) = 2;

% Object label

 objLabel = [1 ;2];

% Spectral features

 spec_feat  = [3 4];

% Calling function

 out_feat = spectral_features_cvip( input_img,mask_img, objLabel, spec_feat )

out_feat = 

  Columns 1 through 4

    'obj_id'    'Spectral_DC_band_1'    'Rings1_band_1'    'Rings2_band_1'
    [     1]    [           1869179]    [   2.9986e+12]    [   6.3262e+10]
    [     2]    [           2616651]    [   4.5460e+12]    [   9.7588e+10]

  Columns 5 through 7

    'Rings3_band_1'    'Sectors1_band_1'    'Sectors2_band_1'
    [   3.5313e+10]    [     5.4117e+12]    [     2.1080e+12]
    [   2.7891e+10]    [     1.0329e+13]    [     2.2241e+12]

  Columns 8 through 10

    'Sectors3_band_1'    'Sectors4_band_1'    'Spectral_DC_band_2'
    [     2.2661e+12]    [     6.5898e+11]    [           1662063]
    [     2.8340e+12]    [     1.0340e+12]    [           4993557]

  Columns 11 through 14

    'Rings1_band_2'    'Rings2_band_2'    'Rings3_band_2'    'Sectors1_band_2'
    [   2.2177e+12]    [   5.5750e+10]    [   3.1541e+10]    [     4.2236e+12]
    [   7.2473e+12]    [   1.3011e+11]    [   4.3527e+10]    [     3.5656e+13]

  Columns 15 through 17

    'Sectors2_band_2'    'Sectors3_band_2'    'Sectors4_band_2'
    [     1.5350e+12]    [     1.7147e+12]    [     4.9543e+11]
    [     4.9259e+12]    [     5.2401e+12]    [     1.2806e+12]

  Columns 18 through 20

    'Spectral_DC_band_3'    'Rings1_band_3'    'Rings2_band_3'
    [           1733443]    [   2.5725e+12]    [   5.6889e+10]
    [           3303625]    [   4.8445e+12]    [   1.0290e+11]

  Columns 21 through 23

    'Rings3_band_3'    'Sectors1_band_3'    'Sectors2_band_3'
    [   3.1260e+10]    [     4.6491e+12]    [     1.7979e+12]
    [   3.0239e+10]    [     1.6001e+13]    [     2.7530e+12]

  Columns 24 through 25

    'Sectors3_band_3'    'Sectors4_band_3'
    [     1.9543e+12]    [     5.7212e+11]
    [     3.1978e+12]    [     1.0172e+12]

SPECTRAL_FEATURES_CVIP

Contents

SYNTAX

DESCRIPTION

REFERENCE

EXAMPLE

CREDITS