I take part in a lesson of Automatic Image Analysis in this semester. And here is my version of the solution of the second exercise.
Figure 2.
Figure 3.
The task of figure 1. is to identify the origin shape after some scaling, moving, rotating operations with the help of so called Hough Transform. The task of figure 2. is a advanced version of the task before, which will identify the money from a complicated scene. The task of figure 3. is mostly used in camera calibration to automatically find out the control points, which then can be used to calculate the calibration matrix and the parameters of camera.
My document(PDF format) of this task is below, if you have interest, maybe you can read it.