How do I use PCA

2 次查看(过去 30 天)
kash
kash 2011-12-17
回答: Gautam 2025-1-2
I have extracted features of an image,and stored in an folder,now i want to select best features from it using PCA AND have to comapre these features ,with the features of query image and retrieve it,please help

回答(1 个)

Gautam
Gautam 2025-1-2
Hello kash,
To perform feature selection using PCA, you can follow the MATLAB code below:
% Center the data
meanFeatures = mean(Features);
centeredFeatures = allFeatures - meanFeatures;
% Perform PCA
[coeff, score, ~, ~, explained] = pca(centeredFeatures);
% Select the number of principal components to retain (e.g., 95% variance)
cumulativeVariance = cumsum(explained);
numComponents = find(cumulativeVariance >= 95, 1);
% Reduce dimensionality
reducedFeatures = score(:, 1:numComponents);
You can further use Euclidean distance to compare the query features with the stored features, and identify the closest matches

类别

Help CenterFile Exchange 中查找有关 Dimensionality Reduction and Feature Extraction 的更多信息

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by