The purpose of this program is to be a practical and didactic introduction on how to perform shifted-linear interpolation. It is a self-contained application that will apply a rigid-body transformation to an image (rotation and translation). The source code (ANSI-C) is divided into 4 principal files ( .c ) and 3 associated header files ( .h ). A standard data file (the famous Lena image) is provided so that you can test the program as soon as it has been downloaded and compiled.