(b) A color digital camera (CDC) Power Shot G3 (Canon, Japan) was located vertically at a distance of 22.5 cm from the sample. The angle between the camera lens axis and the lighting sources was around 45. Sample illuminators and the CDC were inside a wood box whose internal walls were painted black to avoid the light and reflection from the room. The white balance of the camera was set using a standardized gray color chart from Kodak. Color standards were photographed and analyzed periodically to ensure that the lighting system and the CDC were working properly.