When in an emergency, an ISDB-T (Integrated Services Digital Broadcasting-Terrestrial) broadcaster would send a special signal to wake-up their receivers. However, the mobile receivers would wrongly determine the wake-up signal due to the erroneous radio channel. The mobile receivers also need reducing the power consumption when in idle because they are generally battery-operated. In this paper, a method of reliably determining the wake-up signal while reducing the power consumption is proposed. The method uses switching two detection methods and determining the wake-up signal with a certain time observation. The evaluation is conducted in terms of the mutual information to be obtained from the receiver. The combination of the detection method and the determination method maximizes the mutual information.
We previously proposed a novel lossless coding method that utilizes example search and adaptive prediction within a framework of probability model optimization for gray-scale images. In this paper, we extend the method for RGB 4:4:4 formatted color images. In the proposed method, multiple examples are collected from the causal area in not only the same color signal to be encoded but also other color signals as far as they have already been encoded. Moreover, multiple affine predictors trained on a pel-by-pel basis are also utilized to exploit intra- and inter-color correlations. The probability distribution of the color signal at each pel is dynamically modeled by using both examples and predictors. Then a few parameters used in the probability model are numerically optimized for efficient entropy coding. The experimental results show that the proposed method achieves better coding performance than other state-of-the-art lossless coding methods.
A method for image retrieval based on supervised local regression and global alignment (sLRGA) with relevance feedback for insect identification is presented in this paper. Based on the novel sLRGA, which is an extended version of LRGA, the proposed method estimates ranking scores for image retrieval in such a way that the neighborhood structure of a feature space of the database can be optimally preserved with consideration of class information. This is the main contribution of this paper. By measuring the relevance between all of the images and the query image in the database, sLRGA realizes accurate image retrieval. Furthermore, when positive/negative labels to retrieved images are given by users, the proposed method can improve image retrieval performance considering the query relevance information via use of both relevance feedback and sLRGA. This is the second contribution of this paper. Experimental results show the effectiveness of the proposed method.
A novel method for player importance prediction from a player network using gaze positions estimated by Long Short-Term Memory (LSTM) in soccer videos is presented in this paper. By newly using an estimation model of gaze positions trained by gaze tracking data of experienced persons, it is expected that the importance of each player can be predicted. First, we generate a player network by utilizing the estimated gaze positions and first-arrival regions representing players’ connections, e.g., passes between players. The gaze positions are estimated by LSTM that is newly trained from the gaze tracking data of experienced persons. Second, the proposed method predicts the importance of each player by applying the Hypertext Induced Topic Selection (HITS) algorithm to the constructed network. Consequently, prediction of the importance of each player based on soccer tactic knowledge of experienced persons can be realized without constantly obtaining gaze tracking data.
A preserved-color-pixel (PCP) concept is proposed. The PCP color filter array (CFA) is arranged to construct "PCP pixels". A PCP pixel is surrounded by “buffer pixels” having color filters of the same color spectrum as that of the PCP pixel, so that most of color cross-talk from pixels of different colors are absorbed by the buffer pixels. The color cross-talk components of the buffer-pixel signals are computationally canceled by a proposed non-parametric method called "similarity-based blind cross-talk correction (SBC)," where signals of PCP pixels are used as the ground truth to estimate the signals of buffer-pixels without influence of the cross-talk. The demosaicing of each color planes' images sampled with a PCP-CFA arrangement is implemented by the adaptive normalized convolution (ANC) in conjunction with the proposed "post-convolutional-variation-minimization (PCVM)" algorithm for its cost function. Both SBC and PCVM-ANC are especially useful for image acquisition with a pixel array in a sub-half-micron generation, where its pixel pitch is approximately, or smaller than, 0.5 μm. The concept is verified with image simulation, and its effectiveness is quantified with the slanted-edge based spatial frequency response (SFR) modular transfer function (MTF) method by using the parametric color cross-talk analysis based on proposed "scalable-single-parameter (SSP)" color cross-talk model. The image simulation confirms the color reproductivity, together with the effectiveness of image resolution improvement under the influence of the complication of color cross-talk between pixels and lateral chromatic aberration (LCA) of the taking-lens. The benefit is also verified by peak-signal-to-noise-ratio (PSNR) analysis with simulated images based on a real-world picture, indicating that the proposed concept can maintain PSNR when color crosstalk increases.
Communication between screens and cameras has attracted attention as a ubiquitous information source, motivated by the widespread use of smartphones and the increase of public information screens. The method that encodes data into visible patterns impairs the user's visual experience. Previously, embedding matrix barcodes into images on displays by utilizing imperceptible color vibration was proposed. In this approach, the visual experience is maintained considering that barcodes are imperceptible, and it can be implemented on almost any display and camera. Herein, we describe a sophisticated modulation protocol and restoration procedure whereby device characteristics such as the display's gamma feature and the smartphone's rolling shutter are taken into consideration. Extensive experiments reveal the parameters for the modulation and that this system works under practical situations. In addition, scenarios of potential practical applications and a user study examining imperceptibility of barcodes and usability of the system are presented to illustrate the technological capabilities.
In this paper, we assess subjective QoE (Quality of Experience) and objective application-level QoS (Quality of Service) of video IP transmission with error concealment mechanisms of H.264/AVC and AL-FEC (Application-Level Forward Error Correction) of MMT (MPEG Media Transport), which is an application-level protocol for video transmission. The mutual effect is expected to realize more efficient video streaming from a QoE point of view. The experiment treats two contents, two types of the number of slices per picture frame, and two types of the total bitrate of video and its FEC code. We experiment with several load conditions. We then compare FEC schemes with three code rate values and no FEC scheme. We show from the assessment results that the appropriate code rate for QoE enhancement depends on not only network conditions but also contents.