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Digital Watermarking is a technique to embed additional data in digital images, without affecting the original image quality. It has become a useful tool for copyright protection, content authentication and steganography. Least Significant Bit is a commonly used technique in digital image watermarking. It is straight forward to understand and implement, and is widely used in many watermarking algorithms...
Multiview color information used jointly with depth maps is a widespread technique for 3D video. Using this depth information, 3D functionalities such as free view point video can be provided by means of depth-image-based rendering techniques. In this paper, a new technique to encode depth maps is proposed. Based on the usually smooth structure and the sharp edges of depth map, our proposal segments...
With visual information becoming increasingly important, efficient and effective methods for querying and retrieving this kind of information are highly sought after. In this paper, we focus on image information and querying from image collections in an online retrieval fashion. In online retrieval, image features for performing retrieval are not pre-calculated but need to be extracted during the...
We propose a statistical model of natural images in JPEG format. The image acquisition is composed of three principal stages. First, a RAW image is obtained from sensor of Digital Still Cameras (DSC). Then, the RAW image is subject to some post-acquisition processes such as demosaicking, white-balancing and γ-correction to improve its visual quality. Finally, the processed images goes through the...
This paper describes ∑∏-algorithm for fielding the approximation of the function with two independent variables by the sum of products of one-dimensional functions. The offered method of approximation can be used for compression of any two-dimensional information, for example, for compression of experimental data, for packing of tables, for video information compression. Few examples concerning with...
Image retrieval is one of the most exciting and fastest growing research areas in the field of multimedia technology. In this paper, we propose and implement a new image retrieval method that extracts the feature of image using efficient clustering for SURF (Speed Up Robust Feature) scheme, applicable to mobile environments. Since SURF works only on gray-scale images, our clustering SURF is combined...
This paper presents fast fractal image compression algorithm, based on quadtree image partitioning, Fisher block classification, block preparations and multithreaded coding process. Investigation results on efficiency of fractal still grayscale and color images compression are presented with comparison with JPEG results.
In this paper, a classification-based adaptive compression method for computer screen image is presented. This method firstly divides the computer Screen Image into 16x16 non-overlapping blocks, and then every block is classified into three types: text/graphic, pictorial and hybrid blocks based on the characteristics of histogram distribution and the number of colors. For complex text/graphic block,...
Image retrieval is one of the most exciting and fastest growing research areas in the field of multimedia technology. This paper proposes a new efficient image retrieval method that applies a weighted combination of color and texture to the wavelet transform, based on spatial-color and second order statistics, respectively. To evaluate the performance of the proposed algorithm, we assess the simulation's...
The source camera identification problem is concerned with the identification of the camera that has been used to generate a digital picture. A widely adopted identification technique, proposed by Lukas in [1], relies on the usage of the pattern noise left by the camera sensor as a fingerprint. This technique may perform badly when applied to images that have undergone lossy compression techniques,...
Consumer digital cameras use tone-mapping to produce compact, narrow-gamut images that are nonetheless visually pleasing. In doing so, they discard or distort substantial radiometric signal that could otherwise be used for computer vision. Existing methods attempt to undo these effects through deterministic maps that de-render the reported narrow-gamut colors back to their original wide-gamut sensor...
We present a low-complexity integer-reversible spectral-spatial transform that allows for efficient loss less and lossy compression of color-filter-array images (also referred to as camera-raw images). The main advantage of this new transform is that it maps the pixel array values into a format that can be directly compressed in a loss less, lossy, or progressive-to-loss less manner by an existing...
This paper introduces a novel eye region scrambling scheme capable of protecting privacy sensitive eye region information present in video contents. The proposed system consists of an automatic eye detection module followed by a privacy enabling JPEG XR encoder module. An object detection method based on a probabilistic model of image generation is used in conjunction with a skin-tone segmentation...
Unseen visible watermarking (UVW) is a novel data hiding scheme that imitates real-world watermarks and maintains advantages of both visible and invisible watermarking. One important feature of UVW is that specific extraction module is not required during watermarking decoding. The UVW for 2D image is studied based on imaging functions, e.g. gamma-correction in LCD monitors. On the other hand, due...
Virtually all images are stored in compressed form, most in (lossy) JPEG format. Compressing images however has been shown to cause a small but not negligible drop in performance for content-based image retrieval (CBIR) algorithms. In this paper, we show that it is possible to reverse this performance drop. We achieve this by what might at a first glance seem counter-intuitive, namely by compressing...
With image databases expanding rapidly, fast retrieval solutions are highly sought after. Since most images are compressed in JPEG format, compressed-domain retrieval algorithms based on DCT coefficients can be employed to speed up feature extraction and comparison during retrieval. However, this approach is limited as the complete image files need to be read and partially decoded to obtain the required...
Colorization is a method which adds color components to grayscale images using color assigned information provided by the user. Recently, a novel approach to image compression called colorization based coding has been proposed. It automatically extracts color assignations from original color images at an encoder and restores color components by colorization method at a decoder. In this paper, we propose...
Digital images are the most common cover files used for steganography. In this paper, a new steganography method called JMQT based on modified quantization table is proposed. This steganography method is compared with steganography method JPEG-JSteg. Two performance parameters namely capacity and stego size has been compared. As a result capacity increases and stego size increases. So JMQT provides...
While content-based image retrieval (CBIR) has been an active research area over many years, most CBIR techniques operate in the pixel domain even though images are typically stored in compressed form. Consequently, image decoding is required prior to feature calculation leading to a computational overhead that is prohibitive in particular for the case of online retrieval. However, as has been shown...
Saliency detection plays important roles in many image processing applications, such as regions of interest extraction and image resizing. Existing saliency detection models are built in the uncompressed domain. Since most images over Internet are typically stored in the compressed domain such as joint photographic experts group (JPEG), we propose a novel saliency detection model in the compressed...
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