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This paper considers specific aspects of lossy compression of noisy remote sensing images. A method based on discrete cosine transform (DCT) in 32×32 pixels blocks is analyzed. Characteristics of noise assumed additive (in original data or after proper variance stabilizing transform), spatially uncorrelated and Gaussian are assumed a priori known. They are taken into consideration in setting quantization...
It is often needed to compress images with providing certain properties or quality. Wavelet based coders SPIHT and JPEG2000 easily produce a desired compression ratio but not quality especially if one deals with compressing images corrupted by noise for which specific behavior of quality metrics on compression ratio (CR) or bpp might be observed. In particular, optimal operation point (OOP) where...
This paper deals with prediction of compression ratio (CR) in lossy compression of noisy remote sensing images using techniques based on discrete cosine transform (DCT). Properties of noise assumed additive (in original data or after proper variance stabilizing transform) are taken into account by setting quantization step (QS) proportional to noise standard deviation. It is shown that simple statistics...
The paper deals with considering a problem typical for lossy compression of remote sensing images. While compressing an image under interest by DCT-based coders which are rather efficient it is desirable to predict what CR will be attained for a given quantization step. We show that such prediction is possible and it can be done easily, quickly, and quite accurately. Moreover, prediction can be done...
We consider practical aspects of lossy compression with application to multispectral images provided by Landsat sensor. Two facts are taken into account: 1) the inherent noise presence and its properties; 2) rather high degree of component correlation. These properties in different degree are used in 2D and 3D lossy compression. Comparison of the suggested approaches has been carried out for some...
Image quality enhancement is a crucial requirement in many applications of digital image and video processing. Removing artifacts which are suffered from image compression will lose simultaneously image texture components. This paper combines Beltrami method and the window derivative to construct the texture map in an attempt to preserve image details during filtering artifacts. Texture map enhancement...
Low-resolution face analysis suffers more significantly from quality degradations than high-resolution analysis. In this work, we will investigate how several face analysis steps are influenced by low image quality and how this relates to the low resolution. In the first step, a simulation of different effects on image quality, namely low resolution, compression artifacts, motion blur and noise is...
This paper proposes an additive watermarking on sparse or compressible coefficients of the host image in presence of blurring and additive noise degradation. The sparse coefficients are obtained through basis pursuit (BP). Watermark recovery is done through deblurring and performance is studied here for Wiener and fast total variation deconvolution (FTVD) techniques; the first one needs the actual...
Block Compressed Sensed (BCS) images reconstructed by the Smoothed Projected Landweber (SPL) equations are severely degraded in visual quality. This work focuses on removal of the noise present in the BCS - SPL reconstructed image. For noise removal the nature of the noise is studied first. A suitable frequency domain filter to mitigate this noise is proposed in this work. Differential Pulse Coded...
In this paper fractal encoding of images using the wavelet transform is proposed. Fractal encoding is used to produce an image with good visual quality in less encoding time. Quadtree partitioning is applied iteratively during encoding, and fractal coding is executed for JPEG, PNG and BMP HD images in two conditions: by supplying the noise to the input image and without any noise added to the input...
Our paper addresses a question of prediction compression ratio in lossy compression of remote sensing images by coders based on discrete cosine transform (DCT) taking into account noise present in these images. Quantization step is set fixed and proportional to noise standard deviation to provide compression in optimal operation point if it exists. Simple statistics of DCT coefficients is used for...
The suggested SPIHT-based (Set Partitioning in Hierarchical Trees) compression method for degraded one-look SAR images is aimed to be realized in onboard radar hardware to improve quality of on-ground registered image. The main idea of the method is to select two segments in the SAR image: with relatively uncorrupted data (after some processing) and data with fully developed speckle. Then, these two...
The paper addresses practical aspects of multichannel images compression. Color and multichannel images are commonly characterized by high degree of component correlation. This property can be exploited in 3D-compression techniques for achieving high compression ratio. The main goal of this paper is to show that 3D-compression on basis of discrete cosine (DCT) transform offers some advantages in comparison...
The article is devoted to the instrumental means of the design of video data link, which are mounted on board the aircraft. The information concerning the possibilities of the program model use for the choice of the basic hosts and image translation options via physical "channel with gaps" is given in the article.
We present a compound image compression scheme based on the dictionary-based Lempel-Ziv-Markov chain algorithm (LZMA), under the framework of High Efficiency Video Coding (HEVC). Through matching strings from the sliding window dictionary, LZMA exploits the characteristics of the repeated patterns over the text and graphics regions of compound images, and represents them compactly. To obtain high...
Video watermarking plays a key role in copyright protection domain of today's world. In the following paper, a blind watermarking algorithm is being proposed in which the watermark information is being embedded by little alteration of some of the value of DCT coefficients of luminance part of video during encoding it in MPEG-2 style. It is obvious that for any type of watermarking the three parameters,...
In this study, an improved Block Truncation Coding (BTC) image compression scheme, namely Near-Aperiodic Dot-Diffused BTC (NADDBTC), is described. Firstly, the existing regular structures for the generation of bitmap are completely modified for aperiodic compressed results. Moreover, an adaptive quantization levels selection strategy and two parameters Class Matrix (CM) and Diffused Matrix (DM) for...
In general, images possess a considerable degree of affine self-similarity, that is, their subblocks are well approximated by a number of other subblocks with the help of affine greyscale transformations. In this paper, we introduce a quite simple, yet formal mathematical model of such affine self-similarity. The traditional measure of approximation is the L2 norm. We also explore the use of mutual...
In this paper, we revisit a number of concepts which have recently proven to be useful in multiscale signal analysis, specifically by replacing the now classical linear scale transition operators by nonlinear ones. Connections between nonlinear perfect reconstruction filter banks and PDE operators used in scale-space theory are established. An application of the proposed nonlinear tools is then given...
This paper addresses quality issues in Medical Image compression and proposes an approach to achieve near-lossless storage of digitized X-ray plates. An image is normalized to the standard deviation of its noise, which is estimated in an unsupervised fashion. The resulting bitmap is encoded without any further loss. The compression algorithm proposed is based on a two-stage recursive interpolation...
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