Modifications of center-surround, spot detection and dot-pattern selective operators

This paper describes modifications of the models of center-surround and dot-pattern selective cells proposed previously. These modifications concern mainly the normalization of the difference of Gaussians (DoG) function used to model center-surround receptive fields, the normalization of center-surround cell responses for average local intensity, the way in which contiguous activity regions in the center-surround cell responses are reduced to single pixels to detect spots and eliminate responses to non-spot features, the way in which groups of spots are detected and the type of output. These modifications are used in the internet implementation of the mentioned models and corresponding biologically motivated image processing operators

Modifications of center-surround, spot detection and dot-pattern selective operators

This paper describes modifications of the models of center-surround and dot-pattern selective cells proposed previously. These modifications concern mainly the normalization of the difference of Gaussians (DoG) function used to model center-surround receptive fields, the normalization of center-surround cell responses for average local intensity, the way in which contiguous activity regions in the center-surround cell responses are reduced to single pixels to detect spots and eliminate responses to non-spot features, the way in which groups of spots are detected and the type of output. These modifications are used in the internet implementation of the mentioned models and corresponding biologically motivated image processing operators.

Digital planning of cranial implants

<p>Computer-aided techniques can be used in the reconstruction of defects in the skull, although there are limitations for large defects. We describe a technique for the digital design of an implant for cranioplasty using one, easy-to-use, piece of generic industrial software that shows a curvature-based, hole-filling algorithm. This approach is suitable for all kinds of defects, including those that extend across the midline of the skull. The workflow gives the user full control over the design, production, and material used for the implant. (C) 2012 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.</p>

Reliability and validity of measurements of facial swelling with a stereophotogrammetry optical three-dimensional scanner

Volume changes in facial morphology can be assessed using the 3dMD DSP400 stereo-optical 3-dimensional scanner, which uses visible light and has a short scanning time. Its reliability and validity have not to our knowledge been investigated for the assessment of facial swelling. Our aim therefore was to assess them for measuring changes in facial contour, in vivo and in vitro. Twenty-four healthy volunteers with and without an artificial swelling of the cheek were scanned, twice in the morning and twice in the afternoon (in vivo measurements). A mannequin head was scanned 4 times with and without various externally applied artificial swellings (in vitro measurements). The changes in facial contour caused by the artificial swelling were measured as the change in volume of the cheek (with and without artificial swelling in place) using 3dMD Vultus software. In vivo and in vitro reliability expressed in intraclass correlations were 0.89 and 0.99, respectively. In vivo and in vitro repeatability coefficients were 5.9 and 1.3 ml, respectively. The scanner underestimated the volume by 1.2 ml (95% CI -0.9 to 3.4) in vivo and 0.2 ml (95% CI 0.02 to 0.4) in vitro. The 3dMD stereophotogrammetry scanner is a valid and reliable tool to measure volumetric changes in facial contour of more than 5.9 ml and for the assessment of facial swelling

Creating a reference database of cargo inspection X-ray images using high energy CT of cargo mock-ups

International audienceCustoms continue to use a wide range of technology in protecting against terrorism and the movement of illicit trade and prohibited imports. The throughput of scanned vehicles and cargo increases and just keeps on growing. Therefore, the need of automated algorithms to help screening officers in inspection, examination or surveillance of vehicles and containers is crucial. In this context, the successful collaboration between manufacturers and customs offices is of key importance. Facing this topic, within the seventh framework program of the European Commission, the project ACXIS “Automated Comparison of X-ray Images for cargo Scanning” arose. This project develops a reference database for X-ray images of illegal and legitimate cargo, procedures and algorithms to uniform X-ray images of different cargo scanners, and an automated identification of potentially illegal cargo