參數coif1在小波分解中的含義是什麼？

Question

我有小波變換的代碼。在這裏他們使用coif1來分解信號。任何人都可以解釋coif1有什麼用？這是什麼意思？

這是代碼：

function wavelet = waveletTransform(image) 
% input: image to process and extract wavelet coefficients from 
% output: 1x20 feature vector containing the first 2 moments of wavelet 
% coefficients 

imgGray = double(rgb2gray(image))/255; 
imgGray = imresize(imgGray, [256 256]); 

coeff_1 = dwt2(imgGray', 'coif1'); 
coeff_2 = dwt2(coeff_1, 'coif1'); 
coeff_3 = dwt2(coeff_2, 'coif1'); 
coeff_4 = dwt2(coeff_3, 'coif1'); 

% construct the feaute vector 
meanCoeff = mean(coeff_4); 
stdCoeff = std(coeff_4); 

wavelet = [meanCoeff stdCoeff]; 

end 

Answer 1

望着Matlab的文檔here和there（文檔參數wname），你會看到，它意味着小波coif1是小波的類型，在這種情況下來自coiflet家族。

它是用作圖像分解過濾器的子波。