1. A method of forming an image from data captured from a coded aperture imaging system comprising the steps of taking a plurality of frames of data recorded by the coded aperture imaging system, each frame of data acquired using a different coded aperture array, taking for each frame of data a decoding pattern corresponding to the coded aperture array used to acquire that frame of data and processing the data to provide an image solution which is a combined regularised least squares fit to all the frames of data.