Transform Domain Quantization Research Articles

Asymmetrically Compressed Stereoscopic 3D Videos: Quality Assessment and Rate-Distortion Performance Evaluation.

Objective quality assessment of stereoscopic 3D video is challenging but highly desirable, especially in the application of stereoscopic video compression and transmission, where useful quality models are missing, that can guide the critical decision making steps in the selection of mixed-resolution coding, asymmetric quantization, and pre- and post-processing schemes. Here we first carry out subjective quality assessment experiments on two databases that contain various asymmetrically compressed stereoscopic 3D videos obtained from mixed-resolution coding, asymmetric transform-domain quantization coding, their combinations, and the multiple choices of postprocessing techniques. We compare these asymmetric stereoscopic video coding schemes with symmetric coding methods and verify their potential coding gains. We observe a strong systematic bias when using direct averaging of 2D video quality of both views to predict 3D video quality. We then apply a binocular rivalry inspired model to account for the prediction bias, leading to a significantly improved full reference quality prediction model of stereoscopic videos. The model allows us to quantitatively predict the coding gain of different variations of asymmetric video compression, and provides new insight on the development of high efficiency 3D video coding schemes.

Super-resolution still and video reconstruction from MPEG-coded video

There are a number of useful methods for creating high-quality video or still images from a lower quality video source. The best of these involve motion compensating a number of video frames to produce the desired video or still. These methods are formulated in the space domain and they require that the input be expressed in that format. More and more frequently, however, video sources are presented in a compressed format, such as MPEG, H.263, or DV. Ironically, there is important information in the compressed domain representation that is lost if the video is first decompressed and then used with a spatial-domain method. In particular, quantization information is lost once the video has been decompressed. Here, we propose a motion-compensated, transform-domain super-resolution procedure for creating high-quality video or still images that directly incorporates the transform-domain quantization information by working with the compressed bit stream. We apply this new formulation to MPEG-compressed video and demonstrate its effectiveness.

Error rates in computer-generated holographic memories

A procedure for predicting the error rates of a computer-generated holographic memory with general transform domain quantization error is developed. The kinoform, ROACH, detour phase binary hologram, and generalized detour phase binary hologram are compared on the basis of error rates and encoding efficiency. Error rates predicted by the analysis are compared with those obtained by computer simulation.