Exercise:PCA and Whitening
From Ufldl
(Initial port from MATLAB exercise comments) |
(→Step 4b: Check covariance) |
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Visualise the covariance matrix. You should see a red line across the diagonal against a blue background. | Visualise the covariance matrix. You should see a red line across the diagonal against a blue background. | ||
| - | === Step 5: ZCA whitening | + | === Step 5: ZCA whitening === |
Now implement ZCA whitening to produce the matrix xZCAWhite. Visualise the data and compare it to the raw data. You should observe that whitening results in, among other things, enhanced edges. | Now implement ZCA whitening to produce the matrix xZCAWhite. Visualise the data and compare it to the raw data. You should observe that whitening results in, among other things, enhanced edges. | ||
Visualise the data, and compare it to the raw data. You should observe that the whitened images have enhanced edges. | Visualise the data, and compare it to the raw data. You should observe that the whitened images have enhanced edges. | ||
