161 |
Image/video compression and quality assessment based on wavelet transformGao, Zhigang, January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 107-117).
|
162 |
Hiding Depth Map in JPEG Image and MPEG-2 VideoWang, Wenyi 08 November 2011 (has links)
Digital watermarking of multimedia content has been proposed as a method for different
applications such as copyright protection, content authentication, transaction
tracking and data hiding.
In this thesis, we propose a lossless watermarking approach based on Discrete Cosine
Transform (DCT) for a new application of watermarking. A depth map obtained from
a stereoscopic image pair is embedded into one of the two images using a reversible
watermarking algorithm. Different from existing approaches which hide depth map
in spatial domain, the depth information is hidden in the quantized DCT domain of
the stereo image in our method. This modification makes the watermarking algorithm
compatible with JPEG and MPEG-2 compression.
After the investigation of the quantized DCT coefficients distribution of the compressed
image and video, The bit-shift operation is utilized to embed the depth map into its associated 2D image reversibly for the purpose of achieving high compression efficiency of the watermarked image and/or video and high visual quality of stereo image and/or video after the depth map is extracted.
We implement the proposed method to analyze its performance. The experimental results show that a very high payload of watermark (e.g. depth map) can be embedded into the JPEG compressed image and MPEG-2 video. The compression efficiency is only slightly reduced after the watermark embedding and the quality of the original image or video can be restored completely at the decoder side.
|
163 |
Hybrid DWT-DCT algorithm for image and video compression applicationsShrestha, Suchitra 23 February 2011
Digital image and video in their raw form require an enormous amount of storage capacity. Considering the important role played by digital imaging and video, it is necessary to develop a system that produces high degree of compression while preserving critical image/video information. There are various transformation techniques used for data compression. Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) are the most commonly used transformation. DCT has high energy compaction property and requires less computational resources. On the other hand, DWT is multiresolution transformation.<p>
In this work, we propose a hybrid DWT-DCT algorithm for image compression and reconstruction taking benefit from the advantages of both algorithms. The algorithm performs the Discrete Cosine Transform (DCT) on the Discrete Wavelet Transform (DWT) coefficients. Simulations have been conducted on several natural, benchmark, medical and endoscopic images. Several QCIF, high definition, and endoscopic videos have also been used to demonstrate the advantage of the proposed scheme.<p>
The simulation results show that the proposed hybrid DWT-DCT algorithm performs much better than the standalone JPEG-based DCT, DWT, and WHT algorithms in terms of peak signal to noise ratio (PSNR), as well as visual perception at higher compression ratio. The new scheme reduces false contouring and blocking artifacts significantly. The rate distortion analysis shows that for a fixed level of distortion, the number of bits required to transmit the hybrid coefficients would be less than those required for other schemes Furthermore, the proposed algorithm is also compared with the some existing hybrid algorithms. The comparison results show that, the proposed hybrid algorithm has better performance and reconstruction quality. The proposed scheme is intended to be used as the image/video compressor engine in imaging and video applications.
|
164 |
Hiding Depth Map in JPEG Image and MPEG-2 VideoWang, Wenyi 08 November 2011 (has links)
Digital watermarking of multimedia content has been proposed as a method for different
applications such as copyright protection, content authentication, transaction
tracking and data hiding.
In this thesis, we propose a lossless watermarking approach based on Discrete Cosine
Transform (DCT) for a new application of watermarking. A depth map obtained from
a stereoscopic image pair is embedded into one of the two images using a reversible
watermarking algorithm. Different from existing approaches which hide depth map
in spatial domain, the depth information is hidden in the quantized DCT domain of
the stereo image in our method. This modification makes the watermarking algorithm
compatible with JPEG and MPEG-2 compression.
After the investigation of the quantized DCT coefficients distribution of the compressed
image and video, The bit-shift operation is utilized to embed the depth map into its associated 2D image reversibly for the purpose of achieving high compression efficiency of the watermarked image and/or video and high visual quality of stereo image and/or video after the depth map is extracted.
We implement the proposed method to analyze its performance. The experimental results show that a very high payload of watermark (e.g. depth map) can be embedded into the JPEG compressed image and MPEG-2 video. The compression efficiency is only slightly reduced after the watermark embedding and the quality of the original image or video can be restored completely at the decoder side.
|
165 |
Hybrid DWT-DCT algorithm for image and video compression applicationsShrestha, Suchitra 23 February 2011 (has links)
Digital image and video in their raw form require an enormous amount of storage capacity. Considering the important role played by digital imaging and video, it is necessary to develop a system that produces high degree of compression while preserving critical image/video information. There are various transformation techniques used for data compression. Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) are the most commonly used transformation. DCT has high energy compaction property and requires less computational resources. On the other hand, DWT is multiresolution transformation.<p>
In this work, we propose a hybrid DWT-DCT algorithm for image compression and reconstruction taking benefit from the advantages of both algorithms. The algorithm performs the Discrete Cosine Transform (DCT) on the Discrete Wavelet Transform (DWT) coefficients. Simulations have been conducted on several natural, benchmark, medical and endoscopic images. Several QCIF, high definition, and endoscopic videos have also been used to demonstrate the advantage of the proposed scheme.<p>
The simulation results show that the proposed hybrid DWT-DCT algorithm performs much better than the standalone JPEG-based DCT, DWT, and WHT algorithms in terms of peak signal to noise ratio (PSNR), as well as visual perception at higher compression ratio. The new scheme reduces false contouring and blocking artifacts significantly. The rate distortion analysis shows that for a fixed level of distortion, the number of bits required to transmit the hybrid coefficients would be less than those required for other schemes Furthermore, the proposed algorithm is also compared with the some existing hybrid algorithms. The comparison results show that, the proposed hybrid algorithm has better performance and reconstruction quality. The proposed scheme is intended to be used as the image/video compressor engine in imaging and video applications.
|
166 |
Image-video compression, encryption and information hiding /Maniccam, Suchindran S. January 2001 (has links)
Thesis (Ph. D.)--State University of New York at Binghamton, Electrical Engineering Department, 2001. / Includes bibliographical references (leaves 50-52).
|
167 |
Exploiting wireless link adaptation and region-of-interest processing to improve real-time scalable video transmissionWong, Chi-wah, Alec., 王梓樺. January 2004 (has links)
published_or_final_version / abstract / toc / Electrical and Electronic Engineering / Master / Master of Philosophy
|
168 |
Reconstructing compressed photo and video dataLewis, Andrew Benedict January 2012 (has links)
No description available.
|
169 |
On efficiency and robustness of adaptive quantization for subband coding of images and video sequencesMan, Hong 12 1900 (has links)
No description available.
|
170 |
Hiding Depth Map in JPEG Image and MPEG-2 VideoWang, Wenyi 08 November 2011 (has links)
Digital watermarking of multimedia content has been proposed as a method for different
applications such as copyright protection, content authentication, transaction
tracking and data hiding.
In this thesis, we propose a lossless watermarking approach based on Discrete Cosine
Transform (DCT) for a new application of watermarking. A depth map obtained from
a stereoscopic image pair is embedded into one of the two images using a reversible
watermarking algorithm. Different from existing approaches which hide depth map
in spatial domain, the depth information is hidden in the quantized DCT domain of
the stereo image in our method. This modification makes the watermarking algorithm
compatible with JPEG and MPEG-2 compression.
After the investigation of the quantized DCT coefficients distribution of the compressed
image and video, The bit-shift operation is utilized to embed the depth map into its associated 2D image reversibly for the purpose of achieving high compression efficiency of the watermarked image and/or video and high visual quality of stereo image and/or video after the depth map is extracted.
We implement the proposed method to analyze its performance. The experimental results show that a very high payload of watermark (e.g. depth map) can be embedded into the JPEG compressed image and MPEG-2 video. The compression efficiency is only slightly reduced after the watermark embedding and the quality of the original image or video can be restored completely at the decoder side.
|
Page generated in 0.0704 seconds