This paper presents a new approach for gesture classification using x-and y-projections of the image and optional depth features. The system uses a 3-D time-of-flight (TOF) sensor which has the big advantage of simplifying hand segmentation. For the presented system, a Photonic-Mixer-Device (PMD) camera with a resolution of 160 × 120 pixels and a frame rate of 15 frames per second is used. The goal of our system is to recognise 12 different static hand gestures. The x-and y-projections and the depth features of the captured image are good enough to use a simple nearest neighbour classifier, resulting in a fast classification. To evaluate the system, a set of 408 images is recorded, 12 gestures from 34 persons. With a 'Leave-One-Out' evaluation, the recognition rate of the system is 94.61 %, and classification time is about 30 ms on a standard PC.

Abstract-Ultrasound (US) is among the most popular diagnostic techniques today. It is non-invasive, fast, comparably cheap, and does not require ionizing radiation. US is commonly used to examine the size, and structure of the thyroid gland. In clinical routine, thyroid imaging is usually performed by means of 2-D US. Conventional approaches for measuring the volume of the thyroid gland or its nodules may therefore be inaccurate due to the lack of 3-D information. This work reports a semi-automatic segmentation approach for the classification, and analysis of the thyroid gland based on 3-D US data. The images are scanned in 3-D, pre-processed, and segmented. Several pre-processing methods, and an extension of a commonly used geodesic active contour level set formulation are discussed in detail. The results obtained by this approach are compared to manual interactive segmentations by a medical expert in five representative patients. Our work proposes a novel framework for the volumetric quantification of thyroid gland lobes, which may also be expanded to other parenchymatous organs.

Abstract-An algorithm is proposed for the 3D modeling of static scenes solely based on the range and intensity data acquired by a Time-of-Flight camera during an arbitrary movement. No additional scene acquisition devices, like inertia sensor, positioning robots or intensity based cameras are incorporated. The current pose is estimated by maximizing the uncentered correlation coefficient between edges detected in the current and a preceding frame at a minimum frame rate of four fps and an average accuracy of 45 mm. The paper also describes several extensions for robust registration like multiresolution hierarchies and projection Iterative Closest Point algorithm. The basic registration algorithm and its extensions were intensively evaluated against ground truth data to validate the accuracy, robustness and real-time-capability.

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Abstract. Thyroid nodule segmentation is a hard task due to different echo structures, textures and echogenicities in ultrasound (US) images as well as speckle noise. Currently, a typical clinical evaluation involves the manual, approximate measurement in two section planes in order to obtain an estimate of the nodule's size. The aforementioned nodule attributes are recorded on paper. We propose instead the semi-automatic segmentation of 2D slices of acquired 3D US volumes with power watersheds (PW) independent of the nodule type. We tested different input seeds to evaluate the potential of the applied algorithm. On average we achieved a 76.81 % sensitivity, 88.95 % precision and 0.81 Dice coefficient. The runtime on a standard PC is about 0.02 s which indicates that the extension to 3D volume data should be feasible.