matlab中实现Gabor滤波器-蒲公英云

matlab中实现Gabor滤波器

男娘i 2022-08-07 20:30 268阅读 0赞

1.spatialgabor.m描述gabor函数

% SPATIALGABOR - applies single oriented gabor filter to an image
%
% Usage:
% [Eim, Oim, Aim] = spatialgabor(im, wavelength, angle, kx, ky, showfilter)
%
% Arguments:
% im - Image to be processed.
% wavelength - Wavelength in pixels of Gabor filter to construct
% angle - Angle of filter in degrees. An angle of 0 gives a
% filter that responds to vertical features.
% kx, ky - Scale factors specifying the filter sigma relative
% to the wavelength of the filter. This is done so
% that the shapes of the filters are invariant to the
% scale. kx controls the sigma in the x direction
% which is along the filter, and hence controls the
% bandwidth of the filter. ky controls the sigma
% across the filter and hence controls the
% orientational selectivity of the filter. A value of
% 0.5 for both kx and ky is a good starting point.
% showfilter - An optional flag 0/1. When set an image of the
% even filter is displayed for inspection.
%
% Returns:
% Eim - Result from filtering with the even (cosine) Gabor filter
% Oim - Result from filtering with the odd (sine) Gabor filter
% Aim - Amplitude image = sqrt(Eim.^2 + Oim.^2)
%

% Peter Kovesi
% School of Computer Science & Software Engineering
% The University of Western Australia
% pk at csse uwa edu au
% http://www.csse.uwa.edu.au/~pk
%
% October 2006

function [Eim, Oim, Aim] = spatialgabor(im, wavelength, angle, kx, ky, showfilter)

if nargin == 5
showfilter = 0;
end

im = double(im);
[rows, cols] = size(im);
newim = zeros(rows,cols);

% Construct even and odd Gabor filters
sigmax = wavelength*kx;
sigmay = wavelength*ky;

sze = round(3*max(sigmax,sigmay));
[x,y] = meshgrid(-sze:sze);
evenFilter = exp(-(x.^2/sigmax^2 + y.^2/sigmay^2)/2)…
.*cos(2*pi*(1/wavelength)*x);

oddFilter = exp(-(x.^2/sigmax^2 + y.^2/sigmay^2)/2)…
.*sin(2*pi*(1/wavelength)*x);

evenFilter = imrotate(evenFilter, angle, ‘bilinear’);
oddFilter = imrotate(oddFilter, angle, ‘bilinear’);

% Do the filtering
Eim = filter2(evenFilter,im); % Even filter result
Oim = filter2(oddFilter,im); % Odd filter result
Aim = sqrt(Eim.^2 + Oim.^2); % Amplitude

if showfilter % Display filter for inspection
figure(1), imshow(evenFilter,[]); title(‘filter’);
end

2.main.m

ori=imread(‘D:\Images\New\Cars\image_0001.jpg’);
grayimg=rgb2gray(ori);
gim=im2double(grayimg);

[Eim,Oim,Aim]=spatialgabor(gim,3,90,0.5,0.5,1);%90-vertical===0-horizontal
imshow(Aim);