Hi. i am trying to implement PCA algorithm on an image but as i was searching i found many do reshaping to the matrix (image). i understand the concept of the PCA but when it comes to the implementation i don't know what's the benefit of reshaping the image. as far as i know reshaping matrix is like resizing the matrix. another question. when i reshape a matrix of 3x3 to 3x1. that means i lost information (i lots 2 columns).