1. A method of determining a change in a state of an object using images of the object, the method comprising: providing a first image of the object and a second image of the object, the first image and the second image being spaced apart in time; performing a plurality of pixel-based change detection algorithms to obtain a plurality of output difference products, each of the products containing change information and pseudo change information; assigning a weight to each of the products; combining the products in accordance with the weights to form a hybrid change product; and applying a threshold to the hybrid change product to detect areas of change.