41829156
Spatiotemporal analysis of face profiles: detection, segmentation, and registration
We use a two-image approach to construct a 3D human facial model for multimedia applications. The images used are those of faces at direct frontal and side views. The selection of the side view from a sequence of facial images is automatically done by applying a spatiotemporal approach to face profile analysis. The extracted side profile is then segmented based on knowledge of known local facial structures. Temporal consistency in the structure of the face under small deviations from the profile image is exploited to improve robustness of the segmentation in the presence of noise and image artifacts. Once the face profile is properly segmented, nine perceptually significant landmarks (fiducial points) on the face are registered based on a local maximum curvature computation. The methods developed are invariant to geometric transformation and are more robust than earlier approaches which rely only on the spatial structure of the face.
47117010
Stylizing 2.5-D video
In recent years considerable interest has been given to non-photorealistic rendering of photographs, video, and 3D models for illustrative or artistic purposes. Conventional 2D inputs such as photographs and video are easy to create and capture, while 3D models allow for a wider variety of stylization techniques, such as cross-hatching. In this paper, we propose using video with depth information (2.5-D video) to combine the advantages of 2D and 3D input. 2.5-D video is becoming increasingly easy to capture, and with the additional depth information, stylization techniques that require shape information can be applied. However, because 2.5-D video contains only limited shape information and 3D correspondence over time is unknown, it is difficult to create temporally coherent stylized animations directly from raw 2.5-D video. In this paper, we present techniques for processing 2.5-D video to overcome these drawbacks, and demonstrate several styles that can be created using these techniques.
16190492
Noise Estimation from a Single Image
In order to work well, many computer vision algorithms require that their parameters be adjusted according to the image noise level, making it an important quantity to estimate. We show how to estimate an upper bound on the noise level from a single image based on a piecewise smooth image prior model and measured CCD camera response functions. We also learn the space of noise level functions how noise level changes with respect to brightness and use Bayesian MAP inference to infer the noise level function from a single image. We illustrate the utility of this noise estimation for two algorithms: edge detection and featurepreserving smoothing through bilateral filtering. For a variety of different noise levels, we obtain good results for both these algorithms with no user-specified inputs.
44673585
Characterization of Errors in Compositing Panoramic Images
A panoramic image has a 360° horizontal field of view, and it can provide the viewer the impression of being immersed in the scene. A panorama is created by first taking a sequence of images while rotating the camera about a vertical axis. These images are then projected onto a cylindrical surface before being seamlessly composited. The cross-sectional circumference of the cylindrical panorama is called thecompositing length. This work characterizes the error in compositing panoramic images due to errors in some of the intrinsic parameters. The intrinsic camera parameters that are considered are the camera focal length and the radial distortion coefficient. We show that the error in the compositing length is more sensitive to the error in the camera focal length. Especially important is the discovery that the relative error in compositing length is always smaller than the relative error in the focal length. This means that the error in focal length can be corrected by iteratively using the composited length to compute a new and more correct focal length. Thiscompositing approach to camera calibrationhas the advantages of not requiring both feature detection and separate prior calibration.
40596005
Survey of image-based representations and compression techniques
We survey the techniques for image-based rendering (IBR) and for compressing image-based representations. Unlike traditional three-dimensional (3-D) computer graphics, in which 3-D geometry of the scene is known, IBR techniques render novel views directly from input images. IBR techniques can be classified into three categories according to how much geometric information is used: rendering without geometry, rendering with implicit geometry (i.e., correspondence), and rendering with explicit geometry (either with approximate or accurate geometry). We discuss the characteristics of these categories and their representative techniques. IBR techniques demonstrate a surprising diverse range in their extent of use of images and geometry in representing 3-D scenes. We explore the issues in trading off the use of images and geometry by revisiting plenoptic-sampling analysis and the notions of view dependency and geometric proxies. Finally, we highlight compression techniques specifically designed for image-based representations. Such compression techniques are important in making IBR techniques practical.
2096181
Video editing using figure tracking and image-based rendering
We describe a new approach to video editing based on the semi-automatic segmentation of video into multiple layers and the composition of layers using image-based rendering. Using figure tracking and background motion estimation, we can segment a moving figure and reconstruct the background. Using geometrically-correct pixel reprojection, layers can be composited on the basis of the geometry of the underlying scene and the position of a virtual camera. We have implemented a prototype editing system called SpliceWorld.
40491047
Domino logic synthesis based on implication graph
In this paper, we present a new approach to the problem of inverter elimination in domino logic synthesis. A small piece of static CMOS logic is introduced to the circuit to avoid significant area penalty resulting from duplication. To maximize the domino logic part and to minimize the static CMOS logic part, a generalized automatic test pattern generation (ATPG)-based logic transformation is proposed to eliminate or relocate a target inverter. Based on the new concept of dominating set of mandatory assignment (DSMA) and the corresponding implication graph, we propose algorithms to identify a minimum candidate set for a target inverter. Experimental results show that logic transformation based on the implication graph can reduce transistor counts by 25% on average, while the delay increases less than 3%.
36636082
An accurate analytical delay model for BiCMOS driver circuits
An analytical delay model for BiCMOS driver circuits is presented. The model is based on physical device parameters and can be used to estimate both the pull-up and the pull-down times for a variety of circuit configurations. The intrinsic delay associated with the bipolar transistors is taken into consideration by using a charge control model that incorporates the high-injection effects upon the current gain and the base transport factor. Separate sets of delay equations are derived for the pull-up and pull-down transient responses to account for significant differences between the two cases. The comparison with SPICE circuit simulation results shows that the new model predicts the respective delay times with less than 10% error in most cases. The influence of device dimensions upon the driver delay time is also investigated. The model has been applied to find an optimal area allocation between the CMOS and bipolar parts of the driver circuit when the total available area is limited as in the standard cell configuration. >
53239407
Logic Transformation for Low Power Synthesis
In this paper we present a new approach to the problem of local logic transformation for reduction of power dissipation in logic circuits. Based on the finite-state input transition (FIT) power dissipation model, we introduce a cost function which accounts for the effects of input capacitance, input slew rate, internal parasitic capacitance of logic gates, interconnect capacitance, as well as switching power. Our approach provides an efficient way of estimating estimating the global effect of local logic transformations in logic circuits. In our approach, the FIT model for the transitive fanout cells of a locally transformed subcircuit can be reused to measure the global power dissipation by varying the input probabilities of the transitive fanout cells. Local logic transformation is carried our based on compatible sets of permissible functions (CSPF). Experimental results show that local logic transformation based on CSPF using our cost function can reduce power consumption by about 36% on average without increase in the worst-case circuit delay.
13510051
An integrated hot-carrier degradation simulator for VLSI reliability analysis
A novel integrated simulation tool is presented for estimating the hot-carrier induced degradation of nMOS transistor characteristics and circuit performance. The proposed reliability simulation tool incorporates an accurate one-dimensional MOSFET model for representing the electrical behavior of locally damaged transistors. The hot-carrier induced oxide damage can be specified by only a few parameters, avoiding extensive parameter extractions for the characterization of device damage. The physical degradation model used in the simulation tool includes both of the fundamental device degradation mechanisms, i.e., charge trapping and interface trap generation. A repetitive simulation scheme has been adopted to ensure accurate prediction of the circuit-level degradation process under dynamic operating conditions. The simulation tool provides information on the evolution of device degradation during long-term operation, and on the performance characteristics of the damaged circuit.<<ETX>>
32568915
Event Sentence Extraction in Korean Newspapers
Information extraction is to extract information about the main events in the text. This paper presents an event sentence extraction method in Korean newspapers for information extraction. Event sentences contain meaningful information such as the agent, the time and the place of an event. To extract these sentences, we acquire various features such as verbs, nouns, noun phrases, 3Ws, and their weights. And then, the system computes weights of sentences and extracts event sentences by our extraction algorithm. The experimental result shows the average precision of 86.1%.