Surface registration from range image fusion

The registration of full 3-D models is an important task in computer vision. Range finders only reconstruct a partial view of the object. Many authors have proposed several techniques to register 3D surfaces from multiple views in which there are basically two aspects to consider. First, poor registration in which some sort of correspondences are established. Second, accurate registration in order to obtain a better solution. A survey of the most common techniques is presented and includes experimental results of some of them

Unsupervised active regions for multiresolution image segmentation

An unsupervised approach to image segmentation which fuses region and boundary information is presented. The proposed approach takes advantage of the combined use of 3 different strategies: the guidance of seed placement, the control of decision criterion, and the boundary refinement. The new algorithm uses the boundary information to initialize a set of active regions which compete for the pixels in order to segment the whole image. The method is implemented on a multiresolution representation which ensures noise robustness as well as computation efficiency. The accuracy of the segmentation results has been proven through an objective comparative evaluation of the method

A review of sensor fusion techniques for underwater vehicle navigation

This work provides a general description of the multi sensor data fusion concept, along with a new classification of currently used sensor fusion techniques for unmanned underwater vehicles (UUV). Unlike previous proposals that focus the classification on the sensors involved in the fusion, we propose a synthetic approach that is focused on the techniques involved in the fusion and their applications in UUV navigation. We believe that our approach is better oriented towards the development of sensor fusion systems, since a sensor fusion architecture should be first of all focused on its goals and then on the fused sensors

Improving Clustering Algorithms for Image Segmentation using Contour and Region Information

In image segmentation, clustering algorithms are very popular because they are intuitive and, some of them, easy to implement. For instance, the k-means is one of the most used in the literature, and many authors successfully compare their new proposal with the results achieved by the k-means. However, it is well known that clustering image segmentation has many problems. For instance, the number of regions of the image has to be known a priori, as well as different initial seed placement (initial clusters) could produce different segmentation results. Most of these algorithms could be slightly improved by considering the coordinates of the image as features in the clustering process (to take spatial region information into account). In this paper we propose a significant improvement of clustering algorithms for image segmentation. The method is qualitatively and quantitative evaluated over a set of synthetic and real images, and compared with classical clustering approaches. Results demonstrate the validity of this new approach

Calibration of a Structured Light-Based Stereo Catadioptric Sensor

Catadioptric sensors are combinations of mirrors and lenses made in order to obtain a wide field of view. In this paper we propose a new sensor that has omnidirectional viewing ability and it also provides depth information about the nearby surrounding. The sensor is based on a conventional camera coupled with a laser emitter and two hyperbolic mirrors. Mathematical formulation and precise specifications of the intrinsic and extrinsic parameters of the sensor are discussed. Our approach overcomes limitations of the existing omni-directional sensors and eventually leads to reduced costs of production

Plane-to-plane positioning from image-based visual servoing and structured light

In this paper we face the problem of positioning a camera attached to the end-effector of a robotic manipulator so that it gets parallel to a planar object. Such problem has been treated for a long time in visual servoing. Our approach is based on linking to the camera several laser pointers so that its configuration is aimed to produce a suitable set of visual features. The aim of using structured light is not only for easing the image processing and to allow low-textured objects to be treated, but also for producing a control scheme with nice properties like decoupling, stability, well conditioning and good camera trajectory

A system to reduce the effect of CCDs saturation

Colour image segmentation based on the hue component presents some problems due to the physical process of image formation. One of that problems is colour clipping, which appear when at least one of the sensor components is saturated. We have designed a system, that works for a trained set of colours, to recover the chromatic information of those pixels on which colour has been clipped. The chromatic correction method is based on the fact that hue and saturation are invariant to the uniform scaling of the three RGB components. The proposed method has been validated by means of a specific colour image processing board that has allowed its execution in real time. We show experimental results of the application of our method

Behaviours implemented using a vision system based on coded light projection

In a search for new sensor systems and new methods for underwater vehicle positioning based on visual observation, this paper presents a computer vision system based on coded light projection. 3D information is taken from an underwater scene. This information is used to test obstacle avoidance behaviour. In addition, the main ideas for achieving stabilisation of the vehicle in front of an object are presented

Colour image of the thorax and abdomen

This is an image taken from Anatomy tv, an interactive resource for teaching and learning in anatomy and physiology which the University Library subscribes to. This image may not be changed, but you may take a copy and present it with other materials and resources you are using so long as they are password protected for access by members of the University only. "All products and all images within the products are protected by copyright. The products and images can only be used for private educational purposes, unless a specific license is purchased for any other usage. For any commercial usage of the images, please contact Primal Pictures Limited. The products allow members of the University of Southampton to ‘copy and paste’ all of the text as well as the images in the 3D-model window and all of the slides. These can then be pasted into nearly any other word-processing or graphics program, including Powerpoint. These resources can be made available to members of the University of Southampton via a password-protected service. This again is designed solely as a service for private educational uses. Like any publisher, Primal Pictures protects itself against copyright infringement. Please do contact Debra Morris in the University Library before using these resources to ensure that conditions are respected. ©Primal Pictures Limited 2007

Internet for Image Searching

"Internet for Image Searching" is a free online tutorial to help staff and students in universities and colleges to find digital images for their learning and teaching. The emphasis of the tutorial is on finding copyright cleared images which are available free; facilitating quick, hassle-free access to a vast range of online photographs and other visual resources. "This tutorial is an excellent resource for anyone needing to know more about where and how to find images online. The fact that it concentrates on copyright cleared images will make it even more valuable for busy learning and teaching professionals, researchers and students alike. It will also serve to inspire confidence in those needing to use images from the web in their work." (Sharon Waller of the Higher Education Academy).

CV workshop - Projecting a professional image

Slides and activity sheets to accompany a set of practical workshop activities which help participants identify some of their individual skills, as the basis for a future coursework to produce a CV

Intute tutorial on image searching

Would you like to learn how to use the Internet to find copyright cleared images for your work, quickly and efficiently?

JISC Digital media internet for image searching

This webpage provides links to image banks and sources of photos which are usable for educational purposes.