Testing Effects of Color Constancy for Images displayed on CRT Devices

In this report we examine the effects of color constancy for images displayed on computer monitors, particularly CRT devices. The motivation for this work is based upon Edwin Land's Retinex Theory which attempts to explain color constancy in human perception. Using Land's theory, we can create images with a severely undersampled color space (down to a full omission of one color component) that are still appropriately interpreted by the human observer. Possible applications of this are compression schemes as well as image enhancement techniques, some of which are already known. We present a simple web-based testing scheme to verify the viability of displaying duo-chrome (e.g. extreme color undersampling) images on CRT devices in different environmental settings. Some results and possible interpretations of these results are also presented

How2Sketch: Generating Easy-To-Follow Tutorials for Sketching 3D Objects

Accurately drawing 3D objects is difficult for untrained individuals, as it requires an understanding of perspective and its effects on geometry and proportions. Step-by-step tutorials break the complex task of sketching an entire object down into easy-to-follow steps that even a novice can follow. However, creating such tutorials requires expert knowledge and is a time-consuming task. As a result, the availability of tutorials for a given object or viewpoint is limited. How2Sketch addresses this problem by automatically generating easy-to-follow tutorials for arbitrary 3D objects. Given a segmented 3D model and a camera viewpoint,it computes a sequence of steps for constructing a drawing scaffold comprised of geometric primitives, which helps the user draw the final contours in correct perspective and proportion. To make the drawing scaffold easy to construct, the algorithm solves for an ordering among the scaffolding primitives and explicitly makes small geometric modifications to the size and location of the object parts to simplify relative positioning. Technically, we formulate this scaffold construction as a single selection problem that simultaneously solves for the ordering and geometric changes of the primitives. We demonstrate our algorithm for generating tutorials on a variety of man-made objects and evaluate how easily the tutorials can be followed with a user study

\pi^0 \pi^0 Production in Proton-Proton Collisions at Tp=1.4 GeV

The reaction pp->pppi0pi0 has been investigated at a beam energy of 1.4 GeV using the WASA-at-COSY facility. The total cross section is found to be (324 +- 21_systematic +- 58_normalization) mub. In order to to study the production mechanism, differential kinematical distributions have been evaluated. The differential distributions indicate that both initial state protons are excited into intermediate Delta(1232) resonances, each decaying into a proton and a single pion, thereby producing the pion pair in the final state. No significant contribution of the Roper resonance N*(1440) via its decay into a proton and two pions is foundComment: Submitted to PL

From 2D to 3D: A case study of NPR and stereoscopic cinema

Our interdisciplinary research is dedicated to exploring the boundaries of stereoscopic filmmaking from an unusual viewpoint: we aim at creating 3D non-photorealistic cinema which allows conciliating a stereoscopic pre-visualization that is oriented to ensure visual comfort with concept tests of NPR applied to a 3D film. In this paper we describe the role of pre-visualization in stereoscopic cinema and our preliminary observations and experience of combining 3D cinema with nonphotorealistic rendering approaches, from the filmmakers’ point of view