William Clocksin

Surface Inspection

The main focus of this completed project was the real time visual inspection of ceramic tiles. This is an interesting and challenging domain for the following reasons:
  • Ceramic tile workpieces (typically 40 to 70 cm square) need to be inspected at a high rate, up to 4 per second.
  • To obtain adequate resolution at high speed, 2048x2048 pixel images are acquired, using a monochrome time-delay integration line-scan camera.
  • Being natural materials, there is a tradition of inspecting tiles according to subjective judgements and intuitions. These are difficult to understand and specify in algorithmic form.
  • There are a large number of potential faults and quality categories, so any automated system must have comprehensive competence.
Over the years, this work was funded partly by an EU-funded BRITE project IMPACT, and by the EU-funded ESPRIT project CERIND. The work was being developed in partnership with Axiom (Cambridge) Ltd., one of the MVH group of companies, and led to the development of the ATIS Textone, Integrale and Impact systems, used in factories in Spain and Italy.

Analysis of Speckle Patterns in Birds' Eggs

I have worked with Andrew Gosler of the Zoology Department of Oxford University on a project to analyze the speckle pattern in birds’ eggs. The pigment variation can give important information about eggshell strength and function. However, measuring this variation manually is a tedious, time-consuming, and invasive procedure. Our part of the project was to develop novel image processing methods to automatically measure and characterise speckle patterns.