Color evaluation of images acquired using open platform camera and mini-spectrometer under natural lighting conditions

We developed a color calibration method of images taken under the natural lighting conditions using a digital image acquisitions system with a geometrical flexibility between the camera system and the object. The color images of the standard color chart with the plain Red, Green, and Blue sections and tomato fruit were taken under the standard and natural lighting conditions using an open platform digital camera, and the color appearance differences between the two types of images were analyzed based on the illuminating radiance spectral characteristics which were obtained using a mini-spectrometer. The virtual standard color chart could be simulated using the simple spectral futures of the natural lighting based on the photosensitive characteristics. As the results, the images acquired under the natural lighting conditions were successfully calibrated by comparing the color parameters of the virtual standard color chart with those taken under the standard lighting condition.