BMVA Computer Vision Summer School 2014 was successfully hosted at Swansea from 30 June to 4 July 2014. A total of 67 delegates from 14 different countries ( 21 from outside UK) were attending the 19th edition of this summer school. 17 speakers from both academia and industry delivered 19 lectures and 2 lab sessions.
EuroVis 2014, hosted by Swansea University in the UK, was the
16th annual visualization gathering organized by the EuroGraphics Working
Group on Data Visualization and supported by the Visualization and Graphics
Technical Committee (VGTC). EuroVis has been a EuroGraphics and VGTC
co-supported international visualization symposium held in Europe annually
since 1999. In 2012 EuroVis graduated to a conference. The conference
attracted 258 delegate from 25 countries throughout the world.
Noise removal for Monte Carlo global illumination rendering is a well known problem, and has seen significant attention from image-based filtering methods. However, many state of the art methods breakdown in the presence of high frequency features, complex lighting and materials. In this work we present a probabilistic image based noise removal and irradiance filtering framework that preserves this high frequency detail such as hard shadows and glossy reflections, and imposes no restrictions on the characteristics of the light transport or materials. We maintain per-pixel clusters of the path traced samples and, using statistics from these clusters, derive an illumination aware filtering scheme based on the discrete Poisson probability distribution. Furthermore, we filter the incident radiance of the samples, allowing us to preserve and filter across high frequency and complex textures without limiting the effectiveness of the filter.
Ian C. Doidge and Mark W. Jones.
CGI 2013, The Visual Computer 29(6-8),707-616, 2013. The final publication is available at www.springerlink.com.
We are pleased to announce our award of Best Paper at Eurographics 2013 for our paper Photon Parameterisation for Robust Relaxation Constraints, Ben Spencer and Mark W. Jones. [Link to paper]
The paper introduces a technique that augments each photon with information about its origin trajectory. Using this, lighting is separable during density estimation queries. Additionally, we spot fine edge detail using PCA allowing us to employ photon relaxation without detrimental effects. This results in high qualify photon maps that reduce variance and can be rendered with very low bandwidth kernels reducing bias. [Link to news on EG.org]
This 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.
Ben Spencer and Mark W. Jones
Computer Graphics Forum, Volume 32, Issue 2pt1, pages 83–92, May 2013. [doi]
Best paper, Eurographics 2013.
Researchers from Swansea, Cardiff, Aberystwyth and Bangor all attended the 2013 RIVIC graduate school in Bangor and Portmeirion 10th-11th April. Portmeirion was a great setting for the conference – we took over all of the village and some of the castle. We had lots of great talks from PhD students, researchers, lecturers and guest speakers of Hans-Peter Seidel and Min Chen.
Ben Spencer and Mark W. Jones have again won the Computer Graphics Forum cover competition. The winning image will be used throughout 2013 as the front cover image of the journal Computer Graphics Forum. The image shows a visualisation of the parameter space of photon trajectory from the emitting light source. When encoded into the photon map, this can be used to distinguish overlapping light envelopes typically associated with caustics. This enables more accurate density estimation along overlapping illumination, thus producing more accurate renders. The technique is described in an upcoming Eurographics 2013 paper. See their previous prize winning entry for 2009.
The 16th Conference on Medical Image Understanding and Analysis (MIUA) was held at Swansea University this year. Swansea University is set in rolling parkland overlooking the majestic sweep of Swansea Bay. The campus is a stone’s throw from the old fishing village of Mumbles and a short distance to the Maritime Quarter. The University enjoys a prime position overlooking Swansea Bay, the start of the famously dramatic Gower coastline. MIUA is the principal UK forum for communicating research progress within the community interested in image analysis applied to medicine and related biological science.