中国科学院机构知识库网格系统: 检索

Sparse representation for robust abnormality detection in crowded scenes 期刊论文 OAI收割
PATTERN RECOGNITION, 2014, 卷号: 47, 期号: 5, 页码: 1791-1799
作者: Zhu, Xiaobin; Liu, Jing; Wang, Jinqiao; Li, Changsheng; Lu, Hanqing

收藏 | 浏览/下载：43/0 | 提交时间：2015/08/12

Nonnegative matrix factorization Crowded scene Abnormality detection Sparse coding Earth mover's distance Wavelet EMD

Adaptively post-encoding multiple description video coding 期刊论文 OAI收割
neurocomputing, 2013, 卷号: 101, 页码: 149-160
作者: Lan, Xuguang; Yang, Meng; Yuan, Yuan; Zhao, Songlin; Zheng, Nanning

收藏 | 浏览/下载：36/0 | 提交时间：2015/06/08

Multiple description coding Scalable wavelet coding Lagrangian rate allocation Post-encoding

Rate pre-allocated compression for mapping image based on wavelet and rate-distortion theory 期刊论文 OAI收割
OPTIK, 2013, 卷号: 124, 期号: 14, 页码: 1836-1840
作者: Li, Qihu; Ren, Guoqiang; Wu, Qinzhang; Zhang, Xianyu

收藏 | 浏览/下载：30/0 | 提交时间：2015/04/17

Integer wavelet transform Bit rate pre-allocated Image coding FPGA Multiple DSP

Image coding using wavelet-based compressive sampling (EI CONFERENCE) 会议论文 OAI收割
2012 5th International Symposium on Computational Intelligence and Design, ISCID 2012, October 28, 2012 - October 29, 2012, Hangzhou, China
作者: Li J.; Li J.; Li J.

收藏 | 浏览/下载：49/0 | 提交时间：2013/03/25

In this paper we proposed a novel coding scheme is proposed using wavelet-based CS framework for nature image. First two-dimension discrete wavelet transform (DWT) is applied to a nature image for sparse representation. After multi-scale DWT the low-frequency sub-band and high-frequency sub-bands are re-sampled separately. According to the statistical dependences among DWT coefficients we allocate different measurements to low- and high-frequency component. Then the measurements samples can be quantized. The quantize samples are entropy coded and forward correct coding (FEC). Finally the compressed streams are transmitted. At the decoder one can simply reconstruct the image via l1 minimization. Experimental results show that the proposed wavelet-based CS scheme achieves better compression performance against the relevant existing solutions.

Arbitrary ROI-based wavelet video coding 期刊论文 OAI收割
neurocomputing, 2011, 卷号: 74, 期号: 12-13, 页码: 2114-2122
作者: Lan, Xuguang; Zheng, Nanning; Ma, Wen; Yuan, Yuan

收藏 | 浏览/下载：21/0 | 提交时间：2011/09/30

ROI Scalable video coding Wavelet

Image compression based on contourlet and no lists SPIHT (EI CONFERENCE) 会议论文 OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者: Zhang S.

收藏 | 浏览/下载：52/0 | 提交时间：2013/03/25

The volume of raw image data captured by the high resolution camera is extremely huge. Thus the efficient image compression method should be used to decrease the bit rate. The image compression method based on wavelet is used more widely nowadays. However two dimensional wavelet is only the tensor product of the one dimensional wavelet whose support region of basis function is extended from interval to square. Contourlet is an image multiscale geometric analysis tool which could represent image sparsely and has strong capability of nonlinear approximation. The basis function of contourlet is multidirectional and anisotropic. Nevertheless contourlet is redundant. So the non-redundant Wavelet Based Contourlet Transform (WBCT) is used in this paper. The SPIHT algorithm is very efficient way to coding the significant coefficients. And the improved no lists SPIHT is more easy to implemented by hardware. Image compression method based on the combination of both wavelet based contourlet transform and no lists SPIHT coding is proposed in the paper. Experiment shows that compared to wavelet based scheme the contourlet scheme can reserve the texture of the image. For barbara test image when coding at low bit rate the PSNR can improve about 0.2dB. 2010 IEEE.

Design and image restoration research of a cubic-phase-plate system (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, April 26, 2010 - April 29, 2010, Dalian, China
作者: Zhang J.; Zhang J.; Zhang J.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

Wave-front coding technology is a novel jointly optical and digital imaging technology which can greatly extend the depth of focus of optical systems. The image restoration process is an important part of wave-front coding technology. Using wave-front coding makes the modulation transfer function(MTF) values of the optical systems change little over a range of several times the depth of focus which means the system MTF is quite insensitive to defocus and there is no zero in the passband. So we can design a single filter for the restoration of images in different defocus positions. However it's hard to avoid noise during image acquisition and transmission processes. These noises will be amplified in the image restoration especially in the high frequency part when the MTF drop is relatively low. The restoration process significantly reduces the system signal to noise ratio this way. Aimed at the problem of noise amplification a new algorithm was proposed which incorporated wavelet denoising into the iterative steps of Lucy-Richardson algorithm. Better restoration results were obtained through the new algorithm effectively solving the noise amplification problem of original LR algorithm. Two sets of identical triplet imaging systems were designed in one of which the cubic-phase-plate was added. Imaging experiments of the manufactured systems were carried and the images of a traditional system and a wave-front coded system before and after decoding were compared. The results show that the designed wave-front coded system can extend the depth of focus by 40 times compared with the traditional system while maintaining the light flux and the image plane resolution. 2010 Copyright SPIE - The International Society for Optical Engineering.

Storage and compression design of high speed CCD (EI CONFERENCE) 会议论文 OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, November 19, 2008 - November 21, 2008, Chengdu, China
Cai X.; Zhai L. P.

收藏 | 浏览/下载：65/0 | 提交时间：2013/03/25

In current field of CCD measurement large area and high resolution CCD is used to obtain big measurement image so that speed and capacity of CCD requires high performance of later storage and process system. The paper discusses how to use SCSI hard disk to construct storage system and use DSPs and FPGA to realize image compression. As for storage subsystem Because CCD is divided into multiplex output SCSI array is used in RAID0 way. The storage system is composed of high speed buffer DMA controller control MCU SCSI protocol controller and SCSI hard disk. As for compression subsystem according to requirement of communication and monitor system the output is fixed resolution image and analog PAL signal. The compression means is JPEG2000 standard in which 9/7 wavelets in lifting format is used. 2 DSPs and FPGA are used to compose parallel compression system. The system is composed of FPGA pre-processing module DSP compression module video decoder module data buffer module and communication module. Firstly discrete wavelet transform and quantization is realized in FPGA. Secondly entropy coding and stream adaption is realized in DSPs. Last analog PAL signal is output by Video decoder. Data buffer is realized in synchronous dual-port RAM and state of subsystem is transfer to controller. Through subjective and objective evaluation the storage and compression system satisfies the requirement of system. 2009 SPIE.

Scalable video object coding & qos control for next generation space internet 期刊论文 iSwitch采集
Science in china series f-information sciences, 2008, 卷号: 51, 期号: 5, 页码: 599-608
作者: Tu GuoFang; Zhang Can; Nimann, Heinrich; Xu Jie; Wu WeiRen

收藏 | 浏览/下载：39/0 | 提交时间：2019/05/10

Qos control Cld Wavelet fractal interpolation Reduced dimension video coding

Wavelet-based contourlet coding using SPECK algorithm (EI CONFERENCE) 会议论文 OAI收割
2008 9th International Conference on Signal Processing, ICSP 2008, October 26, 2008 - October 29, 2008, Beijing, China
Xiu-Wei T.; Xi-Feng Z.; Tie-Fu D.

收藏 | 浏览/下载：57/0 | 提交时间：2013/03/25

We proposed a new still image compression algorithm called CSPECK witch was constructed by the wavelet-based contourlet transform (WBCT) and set partitioning embedded block coding (SPECK). In the WBCT the high frequency sub-band decomposed by the wavelet transform was further decomposed into multiple directional sub-bands by directional filter bank so as to explain the edge and texture of the image more sparsely. The SPECK algorithm exhibits lower complexity and more efficient compression ratio than SPIHT based on WBCT. Experimental results demonstrate that the proposed method is efficient in coding images that possess mostly textures and contours. The simulation results also show that this new coding algorithm increases the PSNR over CSPIHT. 2008 IEEE.