1. Plan B (Exploiting Camera-Projector Homography)

2. Methodology in Summary If the projection screen is flat, it is possible to directly establish the relationship between the camera and projector through comparing camera images and projector slides –Intuitive way of considering this: imagine the flat screen as a mirror, and consider what projectors and cameras are

3. Methodology in Summary By making these comparisons both for the screen itself and a rectangle projected onto the screen, we can recover camera-screen and camera-projector mappings, from which the projector-screen relationship is directly calculable (as shown next)

4. Methodology in Summary

5. Then, this relationship is our image prewarp:

6. What’s Been Done Method has been implemented to the point of (given four corresponding points between image and slide and four between image and screen) producing the four nearest prewarp mappings to each pixel in the image to be projected

7. What’s Left to Do Full debugging and reliability checking Implementation of the “Blend” algorithm which fills pixels based on the characteristics of the nearest four mappings –this method is expected to produce a certain loss of image quality, whose extent remains to be seen