In some cases, it is necessary to process photographs to make them more understandable. False Color Infrared Photography, or FCIR, is a non-destructive technique that plays an important role in the diagnosis of paintings. Each pigment has a unique chemical composition that can be identified by the way it absorbs infrared light. This technique allows to identify many pigments and retouching and to distinguish between strata.
To create an FCIR image, a photography is taken in direct light and with an infrared reflectogram. Each pigment is represented by a particular false color that depends on the interaction with infrared rays. Using sophisticated software, it is possible to manipulate the RGB information. The red component in the RGB image is substituted with infrared, green is substituted with red and blue with green.