Tag Archives: Computer Graphics

RIVIC Graduate School 2014

Tim Weyrich talk at RIVIC graduate school 2014, Swansea

Tim Weyrich talk at RIVIC graduate school 2014, Swansea

The fifth annual RIVIC Graduate School was held 16th-17th June 2014 in Swansea, setting a new record of 37 talks by students and researchers, with 3 keynote talks from Majid Mirmehdi (Bristol), Tim Weyrich (UCL) and Kurt Debattista (Warwick). The event was arranged over two days in sunny Swansea with a wide range of talks in the topics of Vision, Graphics and Visualisation (Visual Computing). Our conference dinner was held in the Grape and Olive, the 27th floor of the Meridian tower offering superb views over Swansea bay, the city and local countryside.

The RIVIC Graduate School is an excellent opportunity for researchers across the RIVIC sites (Swansea, Aberystwyth, Bangor and Cardiff) to meet up, discuss research projects, seek ideas and solutions, collaborate and generally see the active and varied Visual Computing research ongoing across Wales. We also have keynote talks from excellent researchers, including this year from Majid Mirmehdi (Bristol), Tim Weyrich (UCL) and Kurt Debattista (Warwick).

Majid Mirmehdi (Bristol) spoke about the SPHERE project. In particular he gave a case study of using low cost consumer devices such as Kinect to measure progression of rehabilitation. The ultimate aim is to instrument houses with several sensors and video systems to monitor the health of occupants. He also gave some real-time automotive applications such as road sign detection and in car human/car interaction detection.

Tim Weyrich’s (UCL) talk “Bespoke Computer Graphics Systems for Cultural Heritage Applications” demonstrated how off-the-shelf devices can be re-engineered and integrated with novel software and algorithms to provide robust solutions to real-world heritage problems such as matching up smashed mosaic tiles to aid reconstruction and restoration work.

Kurt Debattista’s (Warwick) talk “High-Fidelity Graphics” covered the past, current and future challenges for high quality global illumination rendering in terms of usability, computational load and adoption. Kurt contextualised his work with industrial experience in application areas of car model rendering (with Land Rover) and architectural applications (with Arup).

Ian Doidge successfully defends PhD

Ian Doidge viva photo

From left: Gary, Ian, Mark and Kurt

Today, Ian Doidge successfully defended his PhD thesis: Utilising Path-Vertex Data to Improve Monte Carlo Global Illumination.

Well done Ian. Mark W. Jones was the supervisor, Markus Roggenbach the viva chair, Gary Tam the internal examiner and Kurt Debattista (Warwick) the external.

Ian’s contributions were published as Probabilistic illumination-aware filtering for Monte Carlo rendering and Mixing Monte Carlo and Progressive Rendering for Improved Global Illumination.

Photon Parameterisation for Robust Relaxation Constraints

splitprismThis paper presents a novel approach to detecting and preserving fine illumination structure within photon maps. Data derived from each photon’s primal trajectory is encoded and used to build a high-dimensional kd-tree. Incorporation of these new parameters allows for precise differentiation between intersecting ray envelopes, thus minimizing detail degradation when combined with photon relaxation. We demonstrate how parameter-aware querying is beneficial in both detecting and removing noise. We also propose a more robust structure descriptor based on principal components analysis that better identifies anisotropic detail at the sub-kernel level.We illustrate the effectiveness of our approach in several example scenes and show significant improvements when rendering complex caustics compared to previous methods.

pdficon_largeBen Spencer and Mark W. Jones
Computer Graphics Forum, Volume 32, Issue 2pt1, pages 83–92, May 2013. [doi]

Best paper, Eurographics 2013.

Progressive Photon Relaxation

splitprismWe introduce a novel algorithm for progressively removing noise from view-independent photon maps while simultaneously minimizing residual bias. Our method refines a primal set of photons using data from multiple successive passes to estimate the incident flux local to each photon. We show how this information can be used to guide a relaxation step with the goal of enforcing a constant, per-photon flux. Using a reformulation of the radiance estimate, we demonstrate how the resulting blue noise photon distribution yields a radiance reconstruction in which error is significantly reduced. Our approach has an open-ended runtime of the same order as unbiased and asymptotically consistent rendering methods, converging over time to a stable result. We demonstrate its effectiveness at storing caustic illumination within a view-independent framework and at a fidelity visually comparable to reference images rendered using progressive photon mapping.

pdficon_largeBen Spencer and Mark W. Jones
ACM Transactions on Graphics. 32(1), January 2013 [doi] [bibtex]

Automatic Generation of 3D Caricatures based on Artistic Deformation Styles

Caricatures are a form of humorous visual art, usually created by skilled artists for the intention of amusement and entertainment. In this paper, we present a novel approach for automatic generation of digital caricatures from facial photographs, which capture artistic deformation styles from hand-drawn caricatures. We introduced a pseudo stress-strain model to encode the parameters of an artistic deformation style using “virtual” physical and material properties. We have also developed a software system for performing the caricaturistic deformation in 3D which eliminates the undesirable artifacts in 2D caricaturization. We employed a Multilevel Free-Form Deformation (MFFD) technique to optimize a 3D head model reconstructed from an input facial photograph, and for controlling the caricaturistic deformation. Our results demonstrated the effectiveness and usability of the proposed approach, which allows ordinary users to apply the captured and stored deformation styles to a variety of facial photographs.

Lindsay Clarke, Min Chen and Ben Mora.
IEEE Transactions on Visualization and Computer Graphics, 2011, Vol. 17. No 5, pp. 808-821.

RIVIC Graduate School: Visual Computing

The 2010 Wales RIVIC Visual Computing Graduate School is a four-day meeting, bringing distinguished international scientists in computer graphics, computer vision, image processing, visualization, and other areas of visual computing together to share their expertise, knowledge, wisdom, and vision with young researchers (e.g. PhD students and PostDocs). The school provides a stimulating opportunity for young researchers and Ph.D. students. The participants will benefit from direct interaction and discussions with leaders in Visual Computing. Participants will also have the possibility to present the results of their research, and to interact with their scientific peers, in a friendly and constructive environment. The Graduate School offers scientists and researchers a rare opportunity to explore the future research directions of visual computing, especially the convergence of its different areas. The event features insightful talks from keynote speakers, research presentations, discussion panels, and PhD forums. Its informal social events provide young researchers a valuable opportunity to exchange research experience and explore potentials for collaboration.