Jin-Woong Kim

Efficient camera motion characterization for MPEG video indexing

A novel approach to camera motion analysis is proposed to index videos compressed in MPEG-1 or MPEG-2. Specifically, it fits the motion vectors in the MPEG stream into the two-dimensional affine model to detect basic camera operations automatically. The proposed approach involves (1) the construction of motion vector fields (MVFs) by normalizing the types of motion vectors and filtering out noise; and (2) the qualitative interpretation of camera motions from the estimated model parameters in two levels (frame and temporal segment). Fine segmentation can also be obtained for a video, based on the homogeneity of camera motion in each unit. The advantages of our method lie in its computational efficiency and robustness to noisy environments such as false motion vectors and object motion. The proposed approach is validated by an experiment with real compressed video sequences.

Rich Media Services for T-DMB: 3-D Video and 3-D Data Applications

Mobile TV applications have gained a lot of interest in recent years. The ability to provide the user with a personal viewing experience as well as the flexibility to add new services have made this technology attractive for media companies and broadcasters around the world. In this chapter, we present a novel approach for mobile 3-D video and data services that extend the regular 2-D video service of the Terrestrial Digital Multimedia Broadcasting (T-DMB) system. We demonstrate the main concepts and features of our 3-D DMB approach and discuss our latest research on the efficient compression of stereoscopic 3-D imagery.

Quality Verification of Fixed and Mobile Hybrid 3DTV Services via a Subjective Test of Mixed-resolution Stereoscopic Videos

Various techniques have been developed for efficient compression of stereoscopic 3D videos. Mixed-resolution based approach is one representative bit-rate saving method based on the characteristics of human visual system that the mixed-resolution stereoscopic videos are perceived close to the higher resolution. However, when the difference between the left and right image resolutions is bigger than a certain threshold level, it causes the perceived quality degradation of the 3D images. Subsequently, several researches tried to find the correlation between the difference in resolution and the level of the perceived quality degradation, but they conducted the experiments just considering the difference in resolution without considering the viewing distances, so thereby different results were retrieved from test to test. In this work, we calculated the optimal viewing distance based on the human visual system, and conducted the subjective tests with the calculated viewing distance. With the results, we demonstrate that the fixed and mobile hybrid 3DTV, which is based on mixed-resolution stereoscopic images, can provide the high quality 3D services.

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.