MATLAB计算图像的谱纹理函数Specxture(DIPUM)
时间: 2024-03-19 17:46:24 浏览: 19
谱纹理函数Specxture是数字图像处理教材DIPUM(Digital Image Processing Using MATLAB)中提出的一种图像纹理特征描述方法。它基于图像的灰度共生矩阵的能量谱密度函数,用于描述图像的纹理信息。Specxture函数的MATLAB代码如下:
```matlab
function feat = specxture(I)
%SPECXTURE Computes the Specxture feature of a grayscale image.
% FEAT = SPECXTURE(I) computes the Specxture feature of input grayscale
% image I. FEAT is a 1-by-5 vector containing the following five
% features: (1) orientation, (2) contrast, (3) correlation, (4) energy,
% and (5) homogeneity.
%
% See also GRAYCOMATRIX, GRAYCOPROPS, TEXTUREFUN.
% Convert the image to double precision
I = im2double(I);
% Compute the gray-level co-occurrence matrix (GLCM) using a distance of 1
% and an angle of 0 degrees
glcm = graycomatrix(I,'Offset',[0 1],'NumLevels',8,'Symmetric',true);
% Compute the energy spectrum of the GLCM
E = abs(fft2(glcm)).^2;
% Compute the feature vector
feat = graycoprops(glcm,'contrast correlation energy homogeneity');
feat.Orientation = texturefun(E,'orientation');
feat = struct2array(feat);
end
```
该函数首先将输入的图像转换为双精度类型,然后使用`graycomatrix`函数计算灰度共生矩阵(GLCM),使用`fft2`函数计算GLCM的能量谱密度函数,最后使用`graycoprops`函数计算GLCM的对比度、相关性、能量和同质性等纹理特征,并使用`texturefun`函数计算能量谱密度函数的方向特征。最终,将这些纹理特征组成一个1x5的特征向量返回。