The efficient extraction of model silhouettes is essential in many applications, such as non-photorealistic rendering, backface culling, shadow computation, and computing swept volumes. For dynamically moving viewpoints, efficient silhouette extraction is more important for system performance. Accordingly, this paper presents an incremental update algorithm for computing a perspective silhouett...

A novel approach for human silhouette recognition is presented. The method is based on Fourier descriptors. We made an analysis of which and how many descriptors are enough to have a general human silhouette representation, and concluded that a reduced number of components, low and high frecuency, is sufficient for representing a human silhouette and for its recognition in different posses. Bas...

This paper presents a method for human action recognition using silhouette histogram. The human silhouette is obtained by using the background subtraction method and then mapped into three different polar coordinate systems that characterize three parts of a human figure respectively. Each polar coordinate system is quantized by partitioning it into several cells with different radii and angles...

A method for reconstructing shape of an object from its silhouette using a mobile camera to which a gyro sensor is attached is proposed. In order to determine unknown camera positions at which images are taken, the pose information of the camera derived from the attached gyro sensor as well as silhouette of the object are used. An algorithm for computing the camera positions by an iterative pro...

In shadow volume rendering, the shadow volume silhouette edges are used to create primitives that model the shadow volume. A common misconception is that the vertices on such silhouettes can only be connected to two silhouette edges, i.e., have degree two. Furthermore, some believe that the degree of such a vertex can have any degree. In this short note, we present a geometric proof that shows ...

In this paper we show that diversity-driven widening, the parallel exploration of the model space with focus on developing diverse models, can improve hierarchical agglomerative clustering. Depending on the selected linkage method, the model that is found through the widened search achieves a better silhouette coefficient than its sequentially built counterpart.

Silhouettes arise in a variety of imaging scenarios. Pristine silhouettes are often degraded via blurring, detector sampling, and detector noise. We present a maximum a posteriori estimator for the restoration of parameterized facial silhouettes. Extreme dealiasing and dramatic superresolution, well beyond the diffraction limit, are demonstrated through the use of strong prior knowledge.

Anemia is sometimes the sole cause of enlargement of the so-called cardiac silhouette. Successful treatment of the anemia may then restore the silhouette to normal. The enlargement has been attributed to cardiac dilatation. Because of the recognized difficulty in distinguishing l)ericarlial effusion from cardiac dilatation, direct puncture was attempted in two instances of anemnia with the silh...