Wook-Joong Kim

Spatiotemporal adaptive quantization for an efficient video rate control

A new algorithm for the rate control of videos considering the sensitivity of the human visual system (HVS) is presented. The method adopts the three-step structure of MPEG-2 Test Model 5 (TM5) rate control, while a new measure for the macroblock (MB) activity based on spatiotemporal sensitivity is introduced. Experimental results show that the proposed activity measure outperforms the spatial activity of TM5 in picture quality.

Geometric analysis and anti-aliasing filter for stereoscopic 3D image scaling

Image resizing (or scaling) is one of the most essential issues for the success of visual service because image data has to be adapted to the variety of display features. For 2D imaging, the image scaling is generally accomplished by 2D image re-sampling (i.e., up-/down-sampling). However, when it comes to stereoscopic 3D images, 2D re-sampling methods are inadequate because additional consideration on the third dimension of depth is not incorporated. Practically, stereoscopic 3D image scaling is process with left/right images, not stereoscopic 3D image itself, because the left/right Images are only tangible data. In this paper, we analyze stereoscopic 3D image scaling from two aspects: geometrical deformation and frequency-domain aliasing. A number of 3D displays are available in the market and they have various screen dimensions. As we have more varieties of the displays, efficient stereoscopic 3D image scaling is becoming more emphasized. We present the recommendations for the 3D scaling from the geometric analysis and propose a disparity-adaptive filter for anti-aliasing which could occur during the image scaling process.