This volume collects the papers accepted for presentation at MIRAGE 2009. The MIRAGE conference is continuing to receive international recognition, with this year’s presentations coming from 25 countries despite the large worldwide financial crisis. This time Asia submitted far fewer papers than previously and fewer than Europe. France proved to be the most active scientifically with a total of 16 submitted papers. Germany came second (10 submitted papers) and China third (8 papers).

We received a total of 83 submissions and accepted 41 as oral presentations, over the three-day event. All papers were reviewed by three to four members of the Program Committee. The final selection was made by the Conference Chairs.

At this point, we wish to thank the Program Committee and additional referees for their timely and high-quality reviews. We also thank the invited speakers Luc Van Gool, Frank Multon and Raquel Urtasun for kindly accepting to present very interesting talks.

Mirage 2009 was organized by inria Rocquencourt and took place at inria, Rocquencourt, close to Versailles. We believe that the conference proved to be a stimulating experience for all.

This book constitutes the refereed proceedings of the 4th International Conference on Computer Vision/Computer Graphics Collaboration Techniques, MIRAGE 2009, held in Rocquencourt, France, in May 2009. The 41 revised full papers presented were carefully reviewed and selected from a total of 83 submissions. The papers cover a wide range of topics with focus on Computer Vision/Computer Graphics collaboration techniques involving image analysis/synthesis approaches especially concerning theoretical, computational, experimental or industrial aspects of model-based image analysis and image-based model synthesis.