Starting with the linear classifier Model Linear classifier computes scores $s = W x$ for $k$ different visual categories given the image, where $W$ was a matrix and $x$ was an input column vector containing all pixel data of the image. In the case of CIFAR-10, $x$ is a [3072x1] column vector, and $W$ is a [10x3072] matrix, so that the output scores is a vector of 10 class scores.