Topic
Transparency (data compression)
About: Transparency (data compression) is a research topic. Over the lifetime, 316 publications have been published within this topic receiving 4336 citations. The topic is also known as: percepually lossless & perceptual losslessness.
Papers published on a yearly basis
Papers
TL;DR: A joint encryption and compression framework in which video data are scrambled efficiently in the frequency domain by employing selective bit scrambling, block shuffling and block rotation of the transform coefficients and motion vectors is presented.
Abstract: Multimedia data security is very important for multimedia commerce on the Internet such as video-on-demand and real-time video multicast. Traditional cryptographic algorithms/systems for data security are often not fast enough to process the vast amount of data generated by multimedia applications to meet real-time constraints. This paper presents a joint encryption and compression framework in which video data are scrambled efficiently in the frequency domain by employing selective bit scrambling, block shuffling and block rotation of the transform coefficients and motion vectors. The new approach is very simple to implement, yet provides considerable levels of security and different levels of transparency, and has a very limited adverse impact on compression efficiency and no adverse impact on error resiliency. Furthermore, it allows transcodability/scalability, and other content processing functionalities without having to access the cryptographic key and perform decryption and re-encryption.
430 citations
Patent•
28 Mar 1990
TL;DR: In this article, a log polar mapper was used to match the image display to human perceptual resolution to achieve a 25:1 compression ratio with no loss of perceived cues, and then the perceptual channels were separated into low resolution, high discrimination level color and high resolution, low discrimination level contrast edges.
Abstract: Video image compression apparatus and method provides full color, wide field of view, real time imagery having high central resolution. Compression ratios of 1600:1 are achieved thus reducing a required data transmission bandwidth sufficiently to abolish line-of-sight restrictions. Data compression apparatus and method (a) uses a log polar mapper to match the image display to human perceptual resolution to achieve a 25:1 compression ratio with no loss of perceived cues, (b) separates perceptual channels into low resolution, high discrimination level color and high resolution, low discrimination level contrast edges to yield an additional 8:1 compression ratio and (c) applies a data compression technique to yield an additional 8:1 compression ratio. A Gaussian filter is employed in generating a display of the imagery from the compressed data. An operator is provided a capability to rapidly move the high resolution window to any point of interest within the display.
221 citations
30 Oct 1999
TL;DR: A joint encryption and compression framework in which video data are scrambled efficiently in the frequency domain by employing selective bit scrambling, block shuffling and block rotation of the transform coefficients and motion vectors is presented.
Abstract: Multimedia data security is very important for multimedia commerce on the Internet such as video-on-demand and real-time video multicast. Traditional cryptographic algorithms for data security are often not fast enough to process the vast amount of data generated by the multimedia applications to meet the real-time constraints. This paper presents a joint encryption and compression framework in which video data are scrambled efficiently in the frequency domain by employing selective bit scrambling, block shuffling and block rotation of the transform coefficients and motion vectors. The new approach is very simple to implement, yet provides considerable level of security, has minimum adverse impact on the compression efficiency, and allows transparency, transcodability, and other content processing functionalities without accessing the cryptographic key.
149 citations
Patent•
9 May 1996TL;DR: In this article, image data is broken down into cells and iteratively compressed using compression formats that are most appropriate for the contents of the cells, and a determination is first made whether a cell is substantially identical to a succeeding cell in a previous frame.
Abstract: A technique for compressing digital video data provides improved compression over conventional block compression techniques. In this technique, image data is broken down into cells and iteratively compressed. The cells are compressed using compression formats that are most appropriate for the contents of the cells. A determination is first made whether a cell is substantially identical to a succeeding cell in a previous frame. If the cell is substantially identical to the cell in the previous frame, the cell is encoded in compressed form as a duplicate of the previous cell. Moreover, solid-color compression approaches, two-color compression approaches and eight-color compression approaches may be integrated into the compression technique.
117 citations
Patent•
14 Oct 1996TL;DR: In this paper, the disclosed compression method utilizes a combination of both lossy and lossless compression to achieve significant compression while retaining very high subjective quality of the reconstructed or decompressed signal.
Abstract: The disclosed compression method utilizes a combination of both lossy and lossless compression to achieve significant compression while retaining very high subjective quality of the reconstructed or decompressed signal. Methods and apparatus for compression and decompression of digital audio data are provided. In one preferred embodiment, the compression method or apparatus has a bit rate control feedback loop particularly well suited to matching the output bit rate of the data compressor to the bandwidth capacity of a communication channel. Disclosed embodiments trade-off various error sources in order to keep perceptible distortion levels to a minimum for a fixed bit rate. Preferred embodiments also utilize a unique combination of run length and Huffman encoding methods in order to take advantage of both local and global statistics.
113 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 4 |
| 2020 | 3 |
| 2019 | 2 |
| 2018 | 6 |
| 2017 | 9 |
| 2016 | 12 |