This paper discusses the results of a measurement of the spectral char
acteristics of images of bar codes with various colors on various subs
trates with different angles of incidence of the light beam on the sam
ple. Recommendations are given for the choice of the optimum spectral
range and mutual orientation of the sample plane and of the axes of il
lumination and of the readout apparatus. (C) 1996 The Optical Society
of America.