DetectorChecker

Writing about web page https://detectorchecker.azurewebsites.net/

Funded by an Alan Turing Institute seed grant, Julia Brettschneider and Wilfrid Kendall have worked with Martin O’Reilly, Tomas Lazauskas and Oscar Giles of the Turing Research Engineers Group to produce a web app DetectorChecker which can be used to help assess the quality of digital X-ray detectors based on spatial analysis of dysfunctional pixels.

The source for the web tool is also available from GitHub in the form of an R package coupled with a Shiny application.

A manual is available from the HELP tab on the web app. The PDF file DetectorChecker2.pdf gives a quick overview.

We are still improving and extending DetectorChecker and we very much welcome your feedback.

Julia Brettschneider

Wilfrid Kendall

Wilfrid Kendall : 14 Jun 2019 15:27 |  Tags: Bad Pixels; Detectorchecker; Web App |  Comments (1) |  Close comments |  Report a problem

Modelling the Penumbra in Computed Tomography

Kueh, A., Warnett, J. W., Gibbons, G. J., Brettschneider, J., Nichols, T. E., Williams, M. A., & Kendall, W. S. (2016). Modelling the Penumbra in Computed Tomography. Journal of X-Ray Science and Technology, to appear, 14pp.

BACKGROUND: In computed tomography (CT), spot geometry is one of the main sources of error in CT images. Since X-ray tubes do not arise from a point source, artefacts are produced. In particular there is a penumbra effect, leading to poorly defined edges within a reconstructed volume. Penumbra models can be simulated given a fixed spot geometry and the known experimental setup.

OBJECTIVE: This paper proposes to use a penumbra model, derived from Beer’s law, to confirm spot geometry from penumbra data, as well as quantify blurring in the image.

METHODS: Two models for the spot geometry are considered; one consists of a single Gaussian spot, the other is a mixture model consisting of a Gaussian spot together with a larger uniform spot.

RESULTS: The model consisting of a single Gaussian spot has fits which are poor. The mixture model (which adds a larger uniform spot) exhibits much improved fits. The parameters corresponding to the uniform spot are similar across all powers, and further experiments suggest that the uniform spot produces only soft X-rays of relatively low-energy.

CONCLUSIONS: Thus, the precision of radiographs can be estimated from the penumbra effect in the image. The use of a thin copper filter reduces the size of the effective penumbra.

Wilfrid Kendall : 19 Apr 2016 16:08 |  Comments (0) |  Close comments |  Report a problem

Neuroimaging Statistics Research at Warwick

Writing about web page http://www.warwick.ac.uk/tenichols/research/neuro-stat

There are weekly meetings on Thursdays, 12-1, in Zeeman C1.06 on Neuroimaging Statistics, where we discuss papers and our on-going research. All are welcome to join in! Details of each week's topic are in the referenced web-page.

Thomas Nichols : 10 Dec 2013 20:22 |  Tags: Seminar |  Comments (0) |  Close comments |  Report a problem

Applied Topology and Stochastic Geometry fortnightly seminar

Writing about web page http://www2.warwick.ac.uk/fac/sci/statistics/staff/academic-research/kueh/topgeomseminar/

A fortnightly seminar to survey recent progress in the two fields mentioned in the title. Details in attached web-page. All are welcome.

Wilfrid Kendall : 10 Dec 2013 18:47 |  Tags: Seminar |  Comments (0) |  Close comments |  Report a problem

EPSRC announcement

Writing about web page http://www.epsrc.ac.uk/newsevents/pubs/mags/connect/2013/90/Pages/futuremanufacturingwithmathematicalsciences.aspx

The grant for this project is one of six forming an announcement on EPSRC's webpages:

http://www.epsrc.ac.uk/newsevents/pubs/mags/connect/2013/90/Pages/futuremanufacturingwithmathematicalsciences.aspx

Wilfrid Kendall : 11 Jun 2013 13:50 |  Tags: Publicity |  Comments (0) |  Close comments |  Report a problem

Project mentioned in Birmingham Post

Scroll to the bottom of

http://www.birminghampost.co.uk/news/local-news/university-warwicks-statistics-work-brain-4042877

Wilfrid Kendall : 05 Jun 2013 13:12 |  Tags: Publicity |  Comments (0) |  Close comments |  Report a problem

£1.6m funding at the interface of statistics, healthcare and manufacturing

See http://www2.warwick.ac.uk/newsandevents/pressreleases/16316m_funding_at/ for a press release partly about the award of this grant.

Wilfrid Kendall : 23 May 2013 14:52 |  Tags: Publicity |  Comments (0) |  Close comments |  Report a problem

EPSRC Project Proposal

Writing about web page http://gow.epsrc.ac.uk/NGBOViewGrant.aspx?GrantRef=EP/K031066/1

Here is a PDF of the successful proposal for this EPSRC-funded project. It is placed here for the benefit of anyone interested in applying for the Statistics PDRA post which currently being advertised.

Wilfrid Kendall : 01 May 2013 11:54 |  Tags: Overview; Pdra |  Comments (0) |  Close comments |  Report a problem