A method of producing an image is disclosed. At least one symbol is received. A first image with at least one light spot is, optionally, captured by an image capturing apparatus. The performing order of receiving the symbol and capturing the first image may be reversed. The first image is duplicated to provide a plurality of duplicated first images, and the duplicated first images are shifted according to the symbol to obtain a plurality of shifted first images. The brightness values of corresponding pixels of the shifted first images are computed to produce a second image with a light track that traces the symbol.