The trace transform as a tool to invariant feature construction

The trace transform proposed, a generalisation of the Radon transform, consists of tracing an image with straight lines along which certain functionals of the image function are calculated. Different functionals that can be used may be invariant to different transformations of the image. The paper presents the properties a functional must have in order to be invariant to rotation, translation and scaling of the image. With the help of these features we can identify, for example, objects depicted in an image database.