Scalable High Efficiency Video Coding (SHVC) is the scalable extension of the latest video coding standard H. 265/HEVC. Video rate control algorithm is out of the scope of video coding standards. Appropriate rate control algorithms are designed for various applications to overcome practical constraints such as bandwidth and buffering constraints. In most of the scalable video applications, such as video on demand (VoD) and broadcasting applications, encoded Bitstreams with variable Bit rates are preferred to Bitstreams with constant Bit rates. In variable Bit rate (VBR) applications, the tolerable delay is relatively high. Therefore, we utilize a larger buffer to allow more variations in Bitrate to provide smooth and high visual quality of output video. In this paper, we propose a fuzzy video rate controller appropriate for VBR applications of SHVC. A fuzzy controller is used for each layer of scalable video to minimize the fluctuation of QP at the frame level while the buffering constraint is obeyed for any number of layers received by a decoder. The proposed rate controller utilizes the well-known structural similarity index (SSIM) as a quality metric to increase the visual quality of the output video. The proposed rate control algorithm is implemented in HEVC reference software and comprehensive experiments are executed to tune the fuzzy controllers and also to evaluate the performance of the algorithm. Experimental results show a high performance for the proposed algorithm in terms of rate control, visual quality, and rate-distortion performance.

Videos directly captured from a computer or smartphone screen have certain characteristics that differentiate them from camera-captured (CC) ones. These videos are called screen content (SC) videos whose specific encoder has been introduced as a new extension of the HEVC standard called screen content coding (SCC). Most screen content applications are real-time with low delay requiring an accurate rate control. The difference in the characteristics and use of special coding tools such as palette mode, intra block copy, and adaptive color transform in this standard, have affected the mechanism of Bit rate generation and control. This paper presents methods and criteria to evaluate the controllability of the Bit rate of SC videos and compare it with that of CC counterparts. Furthermore, the requirements of SC video rate control are studied. The experimental results indicate that the Bit rate of SC videos is much less controllable than the conventional ones so that the conventional rate-distortion models and Bit rate control algorithms are not effective in coding the SC videos.

In this paper we propose a fingerprint image compression method based on the wavelet transform and SPIHT coder. The proposed method employs the proposed technique of dynamic range reduction which benefits from the bimodality of fingerprint images in order to improve the compression efficiency. In addition, we utilized some image enhancement techniques to alleviate the leakage effect as well as further improve the compression efficiency. We have investigated the impacts of compression on recognition efficiency of compressed images. In this investigation we proposed two new measures of breakdown point and downfall slope based on the recognition accuracy curve versus compression Bit rate, in order to evaluate the fingerprint image compression approaches more sophisticatedly.Experimental results show that the proposed technique of dynamic range reduction decreased the breakdown point by 0.05 bpp in average. The proposed image enhancement techniques improved the recognition accuracy up to 5% at all compression Bit rates higher than the breakdown point. It also decreased the downfall slope. Regarding the PSNR performance, the proposed method outperformed the JPEG2000 and WSQ approaches by 0.8 dB, in average.

A rate control algorithm at the group of picture (GOP) level is proposed in this paper for variable Bit rate applications of the H. 265/HEVC video coding standard with buffer constraint. Due to structural changes in the HEVC compared to the previous standards, new rate control algorithms are needed to be designed. In the proposed algorithm, quantization parameter (QP) of each GOP is obtained by modifying QP of previous GOP according to target Bit rate and buffer status. Buffer status and target Bit rate are input variables selected to expand a two dimensional lookup table. Output of the lookup table is provided in a way to allow short-term variations in Bit rate, in order to reach better and more uniform visual quality of reconstructed video. In addition, a QP cascading technique is used for calculating QP of frames in each GOP that operates like a Bit allocation scheme and causes suitable trade-off between quality and compression rate. Unlike conventional methods, proposed scheme uses a lookup table instead of using a rate-distortion model that significantly reduces the computational complexity. Several video sequences with completely different contents were used for experiments. Some short video sequences are concatenated to attain long video sequences which are closer to variable Bit rate applications. Lookup table based (LUT) proposed algorithm is implemented on HM reference software and compared with λ-domain rate control algorithm (λ-RC) and constant QP (CQP) case that defined as anchor. In almost the same average Bit rate (CQP: 1527. 97, LUT: 1520. 92, λ-RC: 1529. 41), average QP (28. 09, 28. 18, 29. 91) and average peak signal to noise ratio (PSNR) (37. 88, 37. 87, 37. 76) of LUT is closer to CQP than that of λ-RC. Average values of QP standard deviation (1. 13, 2. 28, 4. 27) and PSNR standard deviation (1. 37, 2. 11, 2. 15) of LUT is smaller than λ-RC and closer to CQP. From rate control point of view, minimum buffering delay on average for all video sequences resulted by LUT is the same with that of λ-RC which is one of the best rate controllers proposed for the HEVC (0. 94, 0. 36, 0. 35). Consequently, experimental results show that not only Bit rate is perfectly controlled according to buffer constraints, but also the quality of reconstructed video is well maintained.

The paper aims to investigate the advantages of using adaptive Bit rate in the communication link of a LEO satellite. While doing the study, it is assumed that there is a communication subsystem on-board responsible for gathering the information sent by a number of ground user terminals. The subsystem which operates based on Store-and-Forward (SAF) Scenario, contains two communication links, one for receiving data from user terminals (store case), and the other for forwarding the stored data to an Earth station (forward case). In fact, the current work aims to improve the volume of the data forwarded to Earth station. To this end, the Forward case Bit rate is varied adaptively, and then by analyzing the power budget in a practical condition, the improvement achieved is evaluated. The results specifically obtained for a sample LEO satellite shows that utilizing adaptive Bit rate instead of fixed Bit rate can increase the daily data exchange up to about 100%.

This paper seeks to document the specific structural patterns of Bit Hilanis architecture which were in used in the ancient Near East from the second to the first millennium B.C. The recognition of Bit Hilanis architectural characteristics as well as their provenances and their spread from Anatoly to Palestine have always remained the important issues to be addressed by art historians and archaeologists. The main goal of this paper is to explain the architectural, religious and economic aspects of Bit Hilanis within the Anatolian cultural contexts and assess their cultural interactions with the adjacent areas. To do this we tried to provide a detailed characteristic of Bit Hilani’s architecture and their related arts as the basis to compare material remains from a group of Bit Hilanis. The comparisons were also developed through regarding the descriptions of Bit Hilanis by the different written sources as through which some parts of either the Bit Hilanis structures or their decoration details could be reconstructed.