13946222
High dynamic range video
Typical video footage captured using an off-the-shelf camcorder suffers from limited dynamic range. This paper describes our approach to generate high dynamic range (HDR) video from an image sequence of a dynamic scene captured while rapidly varying the exposure of each frame. Our approach consists of three parts: automatic exposure control during capture, HDR stitching across neighboring frames, and tonemapping for viewing. HDR stitching requires accurately registering neighboring frames and choosing appropriate pixels for computing the radiance map. We show examples for a variety of dynamic scenes. We also show how we can compensate for scene and camera movement when creating an HDR still from a series of bracketed still photographs.
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.
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.
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.
10010061
Energy-efficient skewed static logic design with dual Vt
In this paper, we describe skewed static logic (S/sup 2/L) with topology-dependent dual Vt which exhibits energy-efficient operation. S/sup 2/L consumes less dynamic and static power compared to Monotonic Static (MS) CMOS. Speed degradation of S/sup 2/L can be offset by the accelerator. We have designed NAND-NOR gate chains using 0.18 /spl mu/m CMOS technology and verified that S/sup 2/L reduces energy/spl times/delay over MS CMOS by 27-50%. Synthesis algorithm for S/sup 2/L developed and the experimental results show S/sup 2/L consumes 23% less power than MS CMOS with minor increase in delay.
5789613
ILLIADS: a new fast MOS timing simulator using direct equation-solving approach
By using a direct equation solver of a new MOS circuit primitive with piecewise-linear approximation of electrical waveforms, ILLIADS has been shown to be significantly superior to existing fast MOS timing simulators in both accuracy and speed. For simulation of medium-size digital circuits containing a few hundred transistors (n), ILLIADS has already achieved an O(n), about 3n or more, speedup over SPICE with error less than 3%. The sizes of circuits ILLIADS can handle is not limited by this method and the speedup is expected to grow with the circuit size. The possibility of generating false waveforms caused by merging of parallel transistors is reduced. A modified waveform relaxation algorithm is used to handle circuits with feedbacks as demonstrated through simulation of a ring oscillator and a updown counter.
13001832
Low power and high performance circuit techniques for high fan-in dynamic gates
Domino keeper has to be upsized to keep the noise margin in high fan-in dynamic gates, which increases the power consumption and slows down the evaluation. We propose a four-phase non-full swing keeper design to solve this dilemma. Non-full swing switching at the keeper gate together with alleviated contention help to reduce power consumption and delay. Simulation of 16-input OR gate using 0.13/spl mu/m CMOS SPICE parameters shows that proposed keeper design can reduce power consumption and delay by 26% and 24%, respectively.
40642098
A low-voltage high-speed BiCMOS current switch with enhanced-spectral performance
This paper presents a low-voltage high-speed SiGe BiCMOS current switch. Because the proposed current switch has no resistor unlike the previous BiCMOS current switches, it can be used for low voltage ICs. It enhances spectral performance significantly by alleviating nonlinear parasitic capacitance effect, while keeping high-speed and output current accuracy. Simulation result shows that spurious free dynamic range (SFDR) improvement of 10dB is achieved in 12-bit 1GS/s current-mode D/A converter.
205396452
Video dejittering by bake and shake
Video jittering occurs when the horizontal lines of video image frames are randomly displaced due to the corruption of synchronization signals or electromagnetic interference during video transmission. Inspired by the recent Bayesian/variational dejittering model of Shen (SIAM J. Appl. Math., vol. 64, pp. 1691-1708, 2004), in the current paper we propose a novel dejittering approach nicknamed 'bake-and-shake.' The bake step is to apply Perona-Malik type nonlinear diffusions to 'melt away' or heat up the jittered video frames, based upon which the shake step is able to optimally estimate the individual line jitters and renormalize the jittered images. Numerical implementation of the bake-and-shake algorithm as well as several computational results are presented.