1. A method of incorporating a second image into a primary image the method comprising: utilizing a processor to perform the steps of: (a) creating a curved or wavy vectorial grid adapted for mapping on to the primary image: (b) applying a deforming to the grid using data from the second image; and (c) mapping the deformed grid onto the primary image to create an output image; wherein the second image is revealable by applying a decoder to the output image; wherein the vectorial grid comprises a two-dimensional array of curved or wavy lines; and wherein the decoder is an optical decoder which is a lenticular screen or grating with a like spacing to the vectorial grid, whereby the second image is revealed by viewing the output image through the optical decoder.