How do I perform K-Means clustering of the Olivetti Dataset
I have a couple of observations about this:


Before you run clustering, I'd run some dimensionality reduction model. Pixel data are too noisy to be fed as they are into a model. With dimensionality reduction you get both noise reduction and lower computational costs.
Images usually come as 2D or 3D arrays (depending whether they are in grayscale or coloured). On the other side, k-Means and other sklearn models require your whole dataset as a 2D array. You should process each image and turn it into a 1D array that can be fed as a single observation.


Could you share your clustering code, just to make sure?