1. A method for measuring the spectrum of at least one point in a scene, comprising: characterizing a camera which comprises a multi-color filter array and an array of photosensors; locating the camera at a position with a first orientation so that a scene is within a field of view of the camera; capturing a first image of the scene while the camera is at said position with said first orientation; locating the camera at said position with a second orientation so that the scene is within the field of view of the camera; capturing a second image of the scene while the camera is at said position with said second orientation; transferring the first and second images from the camera to a computer; and computing the spectrum of a point in the scene based on at least said first and second images, said computing being performed by the computer system.