In this paper, an adaptive stereo object tracking system based on a block-based SSD(sum of squared difference) algorithm and camera configuration parameters is proposed. That is, by applying SSD algorithm to the reference image of the previous frame and the input image of the current frame, each location coordinate of a moving target in the right and left images are extracted and the respective shifted distances from the reference target position which is assumed to be at the origin in the initial frame are detected. Using the pan/tilt's moving angle calculated from the target's shifted distance and the configuration parameters of a stereo camera system, the block-mask size of a target object can be adaptively determined. The target image segmented with this block mask is used as a reference image in the next stage of tracking, and it is automatically updated according to the same procedure during the course of target tracking. From some experiments using sequential 48 frames of the dynamic stereo image, it is analyzed that the horizontal and vertical stereo disparities on the target object after stereo tracking are kept to be very low values of 1.5 and 0.4 pixels on average, respectively.
In this paper, we present a primitive system design of a super multi-view (SMV) 3-D display system based on a focused light array (FLA) concept using reflective vibrating scanner array (ViSA). The parallel beam scanning using a vibrating scanner array is performed by moving left and right an array of curvature-compensated mirrors or diamond-ruled reflective grating attached to a vibrating membrane. The parallel laser beam scanner array can replace the polygon mirror scanner which has been used in the SMV 3-D display system based on the focused light array (FLA) concept proposed by Kajiki at TAO (Telecommunications Advancement Organization). The proposed system has great advantages in the sense that it requires neither huge imaging optics nor mechanical scanning parts. Some mathematical analyses and fundamental limitations of the proposed system are presented. The proposed vibrating scanner array, after some modifications and refinements, may replace polygon mirror-based scanners in the near future.
The progressive image transmission allows an approximate image to be built up quickly and details to be transmitted progressively through several passes over the image. This paper describes progressive image transmission scheme using the variable block coding technique in conjunction with variety of quantization schemes in the transform domain. The proposed scheme uses a region growing to partition the images so that regions of the different sizes can be addressed using a small amount of side information. This segmentation divides the image into five different regions that vary in size based on the details within the image. High-detail blocks are classified into four different categories using the energy distribution followed by classified vector quantization (CVQ), and low-detail blocks are encoded with scalar quantization. Simulation results show that the reconstructed images preserve fine and pleasant qualities based on both subjective and mean square error criteria. Also, the receiver reconstructs more details in each stage so that the observer can recognize the image quickly.
The discrete wavelet transform (DWT) has recently emerged as a powerful technique for image compression in conjunction with a variety of quantization schemes. In this paper, a new image coding scheme--classified wavelet transform/vector quantization (DWT/CVQ)--is proposed to efficiently exploit correlation among different DWT layers aiming to improve its performance. In this scheme, DWT coefficients are rearranged to form the small blocks, which are composed of the corresponding coefficients from all the subbands. The block matrices are classified into four classes depending on the directional activities, i.e., energy distribution along each direction. These are further divided adaptively into subvectors depending on the DWT coefficient statistics as this allows efficient distribution of bits. The subvectors are then vector quantized. Simulation results show that under this technique the reconstruction images preserve the detail and structure in a subjective sense compared to other approaches at a bit rate of 0.3 bit/pel.
The discrete wavelet transform is incorporated into the JPEG baseline coder for image coding. The discrete cosine transform is replaced by an association of two-channel filter banks connected hierarchically. The scanning and quantization schemes are devised and the entropy coder used is exactly the same as used in JPEG. The result is a still image coder that outperforms JPEG while retaining its simplicity and most of its existing building blocks. Objective results and reconstructed images are presented.