274 research outputs found
Implementation of Transform Based Techniques in Digital Image Watermarking
Digital image watermarking is used to resolve the problems of data security and copyright protection. In many applications of digital watermarking, watermarked image of good quality are required. But here is a trade-off between number of embedded watermark images and quality of watermarked images. This aspect is quite important in case of multiple digital image watermarking. This project presents a robust digital image watermarking using discrete cosine transform (DCT) method. Compression on a watermarked image can significantly affect the detection of the embedded watermark. The detection of the presence or absence of a watermarked in an image is often affected if the watermarked image has undergone compression. Compression can also be considered as an attack on watermarked images. To show that a particular watermarking scheme is robust against compression, simulation is often relied
DOI: 10.17762/ijritcc2321-8169.15084
Simple Signal Extension Method for Discrete Wavelet Transform
Discrete wavelet transform of finite-length signals must necessarily handle
the signal boundaries. The state-of-the-art approaches treat such boundaries in
a complicated and inflexible way, using special prolog or epilog phases. This
holds true in particular for images decomposed into a number of scales,
exemplary in JPEG 2000 coding system. In this paper, the state-of-the-art
approaches are extended to perform the treatment using a compact streaming
core, possibly in multi-scale fashion. We present the core focused on CDF 5/3
wavelet and the symmetric border extension method, both employed in the JPEG
2000. As a result of our work, every input sample is visited only once, while
the results are produced immediately, i.e. without buffering.Comment: preprint; presented on ICSIP 201
A wavelet interlaced video coding framework
A discrete wavelet transform (DWT) based codec with EBCOT/adaptive coding mode switching/low-band-shift (LBS) is presented in this paper. The adaptive coding mode switching is used for both intra- and inter-frame coding, respectively, to improve the rate vs. distortion (R-D) performance. EBCOT, the coding engine used in JPEG2000 is adopted in this framework because of its embedded R-D optimization capability which is most suitable for the application of a perceptual distortion measure (PDM). LBS is used for motion estimation (ME) in DWT domain, while context based MQ coding is adopted to code the motion vector (MV). The context design of MV coding is derived from H.264
Images Protection Sent to Mobile Devices
With the increasing use of multimedia technologies and mobile\ud
devices, also increases the applications which purpose is to offer information or\ud
to do advertising by means of the sending of images or videos. In this paper, we\ud
approached a digital tourist guide scene in which mobile devices with limited\ud
resources need to receive multimedia information across a wireless connection.\ud
Also we approached that this information is visible only authorized users. We\ud
centre the article on the protection of images on an format of compression\ud
adapted. Standard JPEG 2000 has been selected to offer an optimal balance between\ud
the quality of image and the occupied space. In order to protect the information,\ud
we have worked with selective encryption mechanism, that allow to\ud
obtain a relation of commitment between the computational cost, on having\ud
concealed the information and the concealment degree
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