   rotation of a vector
  Hi everyone,I have a bizarre image system where for an image, I get the cosines of the upper left pixel to the world coordinate system. These values are describing the direction of the columns and rows to the world coordinate system. I guess it's like trying to describe the direction of the upper edge and left edge of a plane in 3D space.For example, I have a sample image with cosines of:   cols: 0/0/-1   rows: 0/1/0which means the columns of the image are running down the negative z axis, and the rows are running up the positive y axis.My question is, how could I figure out the resulting cosine direction would be if I apply an arbitrary rotation to the columns for example? If I apply a 90 degree rotation around some axis, what would the cols cosine turn out to be?Thanks   