The scan formal languages can be used for tight integration of image and video compression, encryption and data hiding. This work presents such a tightly integrated embeddable system, which can be used as a "blac...
详细信息
The scan formal languages can be used for tight integration of image and video compression, encryption and data hiding. This work presents such a tightly integrated embeddable system, which can be used as a "black box" in streaming media. In our previous work we had studied and implemented separate modules for scan compression and scan encryption, using a large Virtex II FPGA for each. There were no implementation of data hiding, no integration of the three aspects of scan, and no complete design for decompression/decryption/unhiding. This paper presents a new architecture and a complete design for scan compression/encryption/hiding, as well as the corresponding decompression/decryption/data unhiding operations. A recent technology based on an embedded processor with reconfigurable fabric extensions has been used for this design, which was carried out to post place and route cycle-accurate simulations with real video sequences. The new design is of substantially lower performance versus the previous reconfigurable implementations of single modules, however, it proves that a low-cost embeddable system can be made for all three operations. This paper presents in detail the different aspects of the architecture, their integration, and their mapping to the fixed and reconfigurable resources of the Stretch S5000 reconfigurable processor. To our knowledge, this is the first tightly integrated compression/encryption/information hiding system to be reported in the literature.
In contrast to pure video servers, advanced multimedia applications such as digital libraries or teleteaching exhibit a mixed workload with massive access to conventional, "discrete" data such as text docume...
详细信息
In contrast to pure video servers, advanced multimedia applications such as digital libraries or teleteaching exhibit a mixed workload with massive access to conventional, "discrete" data such as text documents, images and indexes as well as requests for "continuous data", like video and audio data. In addition to the service quality guarantees for continuous data requests, quality-conscious applications require that the response time of the discrete data requests stay below some user-tolerance threshold. In this paper, we study the impact of different disk scheduling policies on the service quality for both continuous and discrete data. We provide a framework for describing various policies in terms of few parameters, and we develop a novel policy that is experimentally shown to outperform all other policies.
In this paper we examine the problem of object and record retrieval from optical disks. General objects (such as images, documents, etc.) may be long and their length may have high variance. We assume that all the com...
详细信息
In this paper we examine the problem of object and record retrieval from optical disks. General objects (such as images, documents, etc.) may be long and their length may have high variance. We assume that all the components of an object are stored consecutively in storage to speed-up retrieval performance. We first present an optical disk model and an optimal schedule for retrieval of records and objects which qualify in a single query on a file stored on an optical disk device. We then provide exact and approximate analytic results for evaluating the retrieval performance for objects from an optical disk. The analysis provides some basic analytic tools for studying the performance of various file and database organizations for optical disks. The results involve probability distribution of block accesses, probability distributions of span accesses, and probability distribution of seek times. Record retrieval is an important special case. This analysis differs from similar ones in database environments in the following respects: (1) the large size and large variance of the size of objects; (2) crossing of track boundaries by objects; (3) the capability for span access that optical disks provide (e.g., when the optical assembly is located in a given position, information can be read from a number of consecutive tracks (span) with a small additional cost).
暂无评论