Documentation on the Image Calibration
The images were taken with two Nikon Coolpix 5700 digital cameras (called "Pippin" and "Merry"). The images in the database are either the original 1920 X 2560 pixel images, or scaled down versions at 786 X 576 pixels.
The cameras were calibrated in the laboratory of Tom Troscianko at Bristol university Psychology Department, using a method developed by Alejandro Parraga. We are grateful to both Alejandro Parraga and Tom Troscianko for allowing us to use their equipment and helping with the calibration.
In order to gamma-correct the images and convert them from camera-RGB to human-LMS format, the gammas and spectral sensitivities of the three RGB sensors were measured for each camera. A detailed description of the entire calibration process is provided in the following documents: