Key Laboratory of Advanced Display and System Application

Shanghai, China

Key Laboratory of Advanced Display and System Application

Shanghai, China
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Wu J.,Shanghai University | Wang Y.,Key Laboratory of Advanced Display and System Application | Wang Y.,Shanghai University | Zhu K.,Shanghai University | Zhu Y.,Shanghai University
VCIP 2016 - 30th Anniversary of Visual Communication and Image Processing | Year: 2016

Most traditional image coding schemes based on compressed sensing exploited the sparse domain in fixed bases and less consider the image non-stationary characteristic and human visual characteristic, which leads to poor performance of the reconstruction. In this paper, we proposed a novel sparse CS scheme combined with just-noticeable difference (JND) Model and random permutation. Firstly, the DCT-based JND profile has been utilized to remove the perceptual redundancies which also makes the signal sparser, then the random permutation is adopted to balance the sparsity of each block in image. Experimental results show that the proposed perceptual sparse algorithm outperforms some existing approaches, and it can achieve better subjective and objective image quality compared to other algorithms when the sampling rate is above 0.3. © 2016 IEEE.


Yang C.,Shanghai University | An P.,Shanghai University | An P.,Key Laboratory of Advanced Display and System Application | Shen L.,Shanghai University | And 2 more authors.
Circuits, Systems, and Signal Processing | Year: 2017

In the multi-view video plus depth 3D video coding, texture image and depth map are coded jointly. The texture image is utilized for displaying and synthesizing the virtual view as reference image. The depth map provides the scene geometry information and is utilized to synthesize the virtual view at the terminal through Depth-Image Based Rendering technique. The distortion of the compressed texture image and depth map will be propagated to the synthesized virtual view. Besides the coding efficiency of texture image and depth map, bit allocation between texture image and depth map also has a great effect on the synthesized virtual view quality. Several methods are proposed for bit allocation between texture image and depth map, but most of them attempt to allocate a fixed target bitrate based on virtual view distortion model to achieve optimal synthesized virtual view quality, and the modeling process brings extra complexity. In practical application, the video sequence has different contents and fixed bit ratio cannot achieve optimal performance. In this paper, we propose an adaptive bit allocation algorithm for 3D video coding. First, we present a model to estimate the synthesized virtual view distortion, and then adjust the bit ratio between adjacent views and between texture image and depth map at Group of Picture level based on the virtual view quality fluctuation. We adjust the bit ratio to achieve the optimal virtual view quality for different video contents. Experimental results demonstrate that the proposed algorithm can optimally allocate bits to achieve optimal virtual view quality under different target bitrates and for different video contents, and the computational complexity of the proposed algorithm is extremely low. © 2016, Springer Science+Business Media New York.


Zeng Z.,Shanghai University | Zheng H.,Shanghai University | Zheng H.,Key Laboratory of Advanced Display and System Application | Yu Y.,Shanghai University | And 2 more authors.
Applied Optics | Year: 2017

Among the important features of holographic displays are the wide viewing angles and the full color of the reconstructed images. The present work focuses on achievement of both features. We propose an increased-viewingangle full-color holographic display using two tiled phase-only spatial light modulators (SLMs), a 4f concave mirrors system, and a temporal-spatial multiplexing method. The 4f optical system consists of two concave mirrors and serves to increase the viewing angle. A temporal-spatial multiplexing synchronization control (TSMSC) method is developed to achieve a full-color image and to remove the color crosstalk of the image. We calculate RGB phase-only holograms of a computer-generated color pyramid by using a slice-based Fresnel diffraction algorithm. The experimental results indicate that the proposed display system is feasible to reconstruct a full-color holographic 3D image with a viewing angle of 12.8°, which is about 3.8 times wider than the viewing angle formed by a single SLM. © 2017 Optical Society of America.


Zhang Z.,Shanghai University | Chen S.,Shanghai University | Zheng H.,Shanghai University | Zheng H.,Key Laboratory of Advanced Display and System Application | And 4 more authors.
Applied Optics | Year: 2017

The fractional Fourier transform (FRT) has been used for computing holograms in holographic displays due to its continuity of describing wave diffraction in the near field and far field. In this study, we propose a method to realize a full-color holographic 3D display with combined use of the FRT and the free-space Fresnel diffraction. A slice-based optical configuration and the calculation algorithm of the FRT are proposed for generating phase-only holograms of full-color 3D objects. Sequential phase-only holograms are generated for reducing the speckle noise of reconstructed images by the time-averaging effect. Free-space Fresnel diffraction is used for 3D image reconstruction from the generated holograms. The relationship between the fractional orders of different color channels and the free-space Fresnel diffraction distance is analyzed. Chromatic aberrations caused by different wavelengths of RGB lasers are also compensated. A full-color holographic display system using a reflective phase-only spatial light modulator (SLM) is established. Both the numerical and optical reconstruction results demonstrate the feasibility of the proposed method. © 2017 Optical Society of America.


Zhang Z.,Shanghai University | Chen S.,Shanghai University | Zheng H.,Shanghai University | Zheng H.,Key Laboratory of Advanced Display and System Application | And 3 more authors.
Optics InfoBase Conference Papers | Year: 2017

Hologram calculating of 3D object has different computation methods. This paper mainly introduces the principle of slice-based Fresnel diffraction and point-based with Fresnel zone plate (FZP), and analyzes the imaging quality of the numerical reconstruction results by using our proposed methods. The reconstruction results show that Fresnel diffraction method is better in imaging quality. © OSA 2017.


Fu Y.,Shanghai University | Fu Y.,Key Laboratory of Advanced Display and System Application | Wang Y.,Shanghai University | Wang Y.,Key Laboratory of Advanced Display and System Application | And 2 more authors.
ICALIP 2010 - 2010 International Conference on Audio, Language and Image Processing, Proceedings | Year: 2010

Image and video coding in block-based image coding can cause blocking artifacts, which severely degrade visual quality in the compressed sequences. Loop deblocking filter method can reduce these artifacts and improve the video objective and subjective quality obviously. In this paper, we propose an efficient deblocking filtering method for multiview video coding, which considers the color bleeding distortion. Experimental results show that this proposed algorithm outperforms the traditional deblocking algorithm in terms of PSNR and subjective visual quality when QP value is relatively high. ©2010 IEEE.


Xue Y.,Shanghai University | Shi R.,Key Laboratory of Advanced Display and System Application | Liu Z.,Shanghai University
Optical Engineering | Year: 2011

This paper proposes a novel saliency model using multiple region-based features. The original image is initially segmented into a set of regions using the mean shift algorithm, and region merging is performed to obtain a moderate segmentation result. Then, three types of regional saliency measures are calculated using region-based features including local/global color difference, orientation difference, and spatial distribution, and they are integrated into an overall regional saliency measure for each region. Finally, the pixel-wise saliency map is generated by combining regional saliency measures with the distance-weighted color similarity between each pixel and each region. Experimental results demonstrate that our saliency model achieves an overall better saliency detection performance than previous saliency models, and the saliency maps generated using our model are more suitable for content-based applications such as salient object detection, content-aware image retargeting, and object-based image retrieval. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).


Hu Y.-L.,Shanghai University | Hu Y.-L.,Key Laboratory of Advanced Display and System Application | Zhou C.,Key Laboratory of Advanced Display and System Application
Journal of Shanghai University | Year: 2010

In this paper, the design and verification process of an automobile-engine-fan control system on chip (SoC) are introduced. The SoC system, SHU-MV08, reuses four new intellectual property (IP) cores and the design flow is accomplished with 0.35 μm chartered CMOS technology. Some special functions of IP cores, the detailed integration scheme of four IP cores, and the verification method of the entire SoC are presented. To settle the verification problems brought by analog IP cores, NanoSim based chip-level mixed-signal verification method is introduced. The verification time is greatly reduced and the first tape-out achieves success which proves the validity of our design. © 2010 Shanghai University and Springer-Verlag Berlin Heidelberg.


Shi R.,Shanghai University | Liu Z.,Shanghai University | Liu Z.,Key Laboratory of Advanced Display and System Application | Du H.,Shanghai University | And 2 more authors.
IEEE Signal Processing Letters | Year: 2012

Salient object detection is an important technique for many content-based applications, but it becomes a challenging work when handling the cluttered saliency maps, which cannot completely highlight salient object regions and cannot suppress background regions. In this letter, we propose a novel approach to detect salient object from saliency map without manually setting any parameters. Region diversity maximization is used as the objective function to direct the object detection, and the optimal window for locating the salient object is obtained using an efficient iterative search scheme. Experimental results on different saliency maps demonstrate the overall better detection performance and computational efficiency of our approach. © 2012 IEEE.


Liu Z.,Shanghai University | Liu Z.,Key Laboratory of Advanced Display and System Application | Xue Y.,Shanghai University | Shen L.,Shanghai University | And 3 more authors.
Proceedings - International Conference on Image Processing, ICIP | Year: 2010

This paper proposes a nonparametric saliency model based on kernel density estimation (KDE) mainly aiming at content-based applications such as salient object segmentation. A set of KDE models are constructed on the basis of regions segmented using the mean shift algorithm. For each pixel, a set of color likelihood measures to all KDE models are calculated, and then the color saliency and spatial saliency of each KDE model are evaluated based on its color distinctiveness and spatial distribution. The final saliency map is generated by combining saliency measures of KDE models and color likelihood measures of pixels. Experimental results demonstrate the better saliency detection performance of our saliency model. © 2010 IEEE.

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