KeeChang Lee

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We consider the problem of estimating 3-d structure from a single still image of an outdoor urban scene. Our goal is to efficiently create 3-d models which are visually pleasant. We chose an appropriate 3-d model structure and formulate the task of 3-d reconstruction as model fitting problem. Our 3-d models are composed of a number of vertical walls and a(More)
We propose a CMOS image sensor with time-division multiplexing pixel architecture using standard pinned-photodiode for capturing 2-D color image as well as extracting 3-D depth information of a target object. The proposed pixel can alternately provide both color and depth images in each frame. Two split photodiode and four transfer gates in each pixel(More)
Nonlocal means filtering is an edge-preserving denoising method whose filter weights are determined by Gaussian weighted patch similarities. The nonlocal means filter shows superior performance in removing additive Gaussian noise at the expense of high computational complexity. In this paper, we propose an efficient and effective denoising method by(More)
Time-of-Flight depth cameras provide a direct way to acquire range images, using the phase delay of the incoming reflected signal with respect to the emitted signal. These cameras, however, have a challenging problem called range folding, which occurs due to the modular error in phase delay—ranges are modulo the maximum range. To our best knowledge,(More)
A pixel architecture for providing not only normal 2-D images but also depth information by using a conventional pinned photodiode is presented. This pixel architecture allows the sensor to generate a real-time 3-D image of an arbitrary object. The operation of the pixel is based on the time-of-flight principle detecting the time delay between the emitted(More)
This paper presents a novel algorithm for realistic 3D face modeling from a single pair of color and time-of-flight (TOF) depth images using a generic, deformable model. Most previous approaches have attempted to emphasize either facial feature or global shape consistency, resulting in either visually plausible or geometrically accurate models. In this(More)
A 3D image sensor is presented employing a time multiplexed concept for color and depth image acquisition in a single chip to generate a real-time 3D image of an arbitrary scene. The pixel adopts a split photodiode to demodulate time-of-flight signals effectively. Every four pixels share two storages and readout transistors to utilize 100% of photons and(More)
In this paper, we present a 2<sup>nd</sup>-generation 2D/3D imager based on the pinned- photodiode pixel structure. The time-division readout architecture for both image types (color and depth) is maintained. A complete redesign of the imager makes pixels smaller and more sensitive than before. To obtain reliable depth information using a pinned-photodiode,(More)
A Time-of-Flight (ToF) camera uses a near infrared (NIR) to obtain the distance from the camera to an object. The distance is calculated from the amount of time shift between the emitted and reflected NIR. ToF cameras generally modulate NIR with a square wave rather than a sinusoidal wave due to its difficulty in hardware implementation. The previous method(More)