4923907
Lighting And Shadow Interpolation Using Intrinsic Lumigraphs
Densely-sampled image representations such as the light field or Lumigraph have been effective in enabling photorealistic image synthesis. Unfortunately, lighting interpolation with such representations has not been shown to be possible without the use of accurate 3D geometry and surface reflectance properties. In this paper, we propose an approach to image-based lighting interpolation that is based on estimates of geometry and shading from relatively few images. We decompose light fields captured at different lighting conditions into intrinsic images (reflectance and illumination images), and estimate view-dependent scene geometries using multi-view stereo. We call the resulting representation an Intrinsic Lumigraph. In the same way that the Lumigraph uses geometry to permit more accurate view interpolation, the Intrinsic Lumigraph uses both geometry and intrinsic images to allow high-quality interpolation at different views and lighting conditions. The joint use of geometry and intrinsic images is effective in computing shadow masks for shadow prediction at new lighting conditions. We illustrate our approach with images of real scenes.
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.
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.
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.
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.
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.
45749208
A low-power reduced swing single clock flip-flop
A reduced swing single clock flip-flop (RS/sup 2/CFF) is developed to reduce power consumption significantly compared to conventional FFs. RS/sup 2/CFF avoids unnecessary internal node transition and reduce fighting currents. The overall power saving in flip-flop operation is estimated to be 33% with additional 64% power savings in clock network.
1915383
Leakage-proof domino circuit design for deep sub-100 nm technologies
The leakage power consumption in deep sub-100 nm CMOS systems is projected to become a significant part of the total power dissipation. Although the dual Vt CMOS process helps reduce the subthreshold leakage current in domino circuits, the gate leakage problem poses a significant design challenge. We propose two new circuit techniques to suppress both subthreshold leakage current and gate leakage current in domino circuits. In standby mode, subthreshold leakage current is suppressed by using dual Vt devices in the two proposed circuits. The proposed circuits generate low inputs and low outputs to suppress gate leakage current in the NMOS logic tree in standby mode. Simulation results based on 45 nm BSIM4 models show that 32-bit adders using the two proposed circuits can reduce the total standby leakage by 83.2% and 93.2%, respectively, compared with the adder using single Vt domino circuits. Proposed adders have 7% active power overhead to achieve the same speed as single Vt domino adder and the area penalty is minimal with careful layout.
18755002
Color image decomposition and restoration
Meyer has recently introduced an image decomposition model to split an image into two components: a geometrical component and a texture (oscillatory) component. Inspired by his work, numerical models have been developed to carry out the decomposition of gray scale images. In this paper, we propose a decomposition algorithm for color images. We introduce a generalization of Meyer’s G norm to RGB vectorial color images, and use Chromaticity and Brightness color model with total variation minimization. We illustrate our approach with numerical examples.
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%.
9186181
New simulation methods for MOS VLSI timing and reliability
A novel approach to incorporating the channel length modulation in a direct-equation solving fast timing simulator is presented along with a mixed event-driven and waveform relaxation algorithm to handle MOS VLSI circuits with feedback. Simulation speedup of 3N over SPICE-like simulators has been observed, where N is the number of transistors. The simulator is able to simulate circuits as large as 235000 transistors in 10 min real time. Also presented is a novel approach to fast hot-carrier reliability simulation. These methods make it possible to achieve accurate and fast hot-carrier reliability simulation of MOS circuits each with as many as hundreds of thousands of MOS transistors in a workstation environment.<<ETX>>