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A brief introduction to spatial-domain Super-Resolution methods, i.e. spatial resolution enhancement methods that create one high-resolution image from a series of low-resolution images shifted by a sub-pixel distance, is given. An improvement applicable to some of existing Super-Resolution methods is presented. Principles of digital photography processing techniques are exploited in order to reduce...
We propose and verify a method for color-based cluster segmentation of the various tissues from ectocervix. That method uses a simplified compartment-like analysis, aiming for a Gaussian Mixture Model (GMM)-tailored segmentation. The tissues of interest are the cervical canal (CC), the columnar epithelium (CE), the squamous epithelium (SE) and the transformation zone (TZ) the latter known as area...
Lossless video compression is a novel research area, but it is gaining widespread importance. As an example, in digital cinema the post-production chain requires all the information captured by digital cameras, and any data loss is not tolerated. On the other hand, the camera sensors size is expected to grow up to 4k × 2k pixels at 10 bit per pixel per component, and cameras output frame-rate up to...
Most of the stereo algorithms available today use only Luminance images, assuming that the chromatic channels are redundant. This is based on the assumption that the Luminance channel holds most of the information. We propose to improve the disparity estimation by working in a transformed color space. The optimal color space is found by minimizing the disparity estimation variance, which is calculated...
In this paper we address the problem of the compression of a video sequence acquired by most inexpensive single sensor video cameras. For each pixel in a frame only one chrominance component is available and an interpolation is used to obtain the full color frame. Our goal is to compress the video directly from the Bayer color filter array (CFA) data. We propose a new method for the reduction of temporal...
The paper presents a technique for the segmentation of colour images from video sequences. The technique is aimed at the extraction of multiple objects in the presence of background motion, and without global motion compensation. A modified version of the Multi-label Fast Marching algorithm is used in the segmentation process. The most important modification allows segment merging as well as pushing...
Binary and grayscale mathematical morphology have many applications in different domains. On the other hand, colour morphology is not widespread. The reason is the lack of a suitable colour ordering strategy that makes the extension of grayscale morphology to colour images not straightforward. We will introduce a new majority sorting scheme (MSS) that can be applied to binary, grayscale and colour...
In this work, we propose an efficient image and video colorization algorithm. To achieve natural colorization, we first define initial color values and compute their reliabilities. For image colorization, initial colors are assigned by the user interaction. For video colorization, initial colors are transferred from the previous frame and their reliabilities are computed based on the motion information...
In this paper a new morphological technique suitable for colour image skeleton extraction is presented. Vector morphological operations are defined by means of a new ordering of vectors of the HSV colour space, which is a combination of conditional and partial sub-ordering. Then, these are used to extract skeletons of colour images in terms of erosions and openings. The proposed method was tested...
A novel hierarchical clustering method is presented in this work. It operates as a part of a split and merge segmentation scheme. The proposed technique incorporates the use of several color features to compare clusters in the RGB space and the flexibility of the fuzzy reasoning approach to accomplish satisfactory segmentation results. The boundary values of the fuzzy sets have been determined by...
There has been a rapid increase in audio-visual information in digital form with the ever-increasing popularity of the Internet. The Moving Pictures Expert Group has recently presented a video compression and content manipulation standard, called MPEG-4 [1]. This was developed in response to the growing need for a coding method that can facilitate access to visual objects in natural and synthetic...
We present a method to improve the performance of content-based image retrieval (CBIR) systems. The idea is based on the concept of query models [1], which generalizes the notion of similarity in multi-feature queries. In a query model features are organized in layers. Each succeeding layer has to investigate only a subset of the image set the preceding layer had to examine. For the purpose of performance...
In this work we propose an algorithm for the estimation of high resolution color frames from a low resolution compressed color video sequence. The algorithm exploits the existing correlation between the high and low resolution frames to obtain a high resolution frame reducing the artifacts introduced by the compression process. The performance of the proposed algorithm is demonstrated experimentally.
This paper deals with denoising of color video sequences using improved median-based filters appropriate for realtime implementations. In the paper, it is proven that application of prediction error processing results in improved efficiency of video restoration. The basic idea is to predict a pixel value by using a nonlinear filter, and then to calculate the prediction error by a comparison with the...
This paper proposes a new structure for the classical median vector filter. It is based on a vector ordering relation obtained by associating a cumulative distance to each vector. The specifity of the proposed filter relies in the definition of the neighboring window used to calculate this distance. The filter presents both an enhancement and a registration effect, combined with a smoothing effect...
This paper presents a novel Virtual Reality tool for visualising image neighbourhoods. It is currently implemented using RGB colour space, but the technique is not limited to Cartesian spaces. The Visualisation Tool is based on Virtual Reality Modeling Language (VRML). Visualisation using virtual reality techniques is a useful tool to help evaluate the effectiveness of colour filters. It can also...
In this paper, a fuzzy approach is used for efficiently representing the visual content. Initially, the image is partitioned into several segments (objects) and for each segment appropriate features, such as the segment color and texture, are extracted. In the following, all features are classified in a fuzzy framework, resulting in a content interpretation closer to the human perception. Furthermore,...
In this paper we explore a wavelet compression scheme for color images that uses binary vector morphology to aid in the encoding of the locations of the wavelet coefficients. This is accomplished by predicting the significance of coefficients in the sub-bands. This approach fully exploits the correlation between color components and the correlation between and within sub-bands of the wavelet coefficients...
Hypercomplex 2D Fourier transforms have been proposed by several authors with applications in image processing of both grayscale and colour images. Previously published works on hypercomplex Fourier transforms have utilized direct evaluation of a Fast Fourier transform using hypercomplex arithmetic. This paper shows that such transforms may be implemented by decomposition into two independent complex...
Colour edge detection procedures usually aim to find significant discontinuities between all adjacent homogeneous image regions, no matter what the colour. In this paper we present a colour edge detection procedure designed to find edges between homogeneous regions of particular colours. Initially the three-dimensional RGB colour space is modelled as the imaginary subspace of a four-dimensional, hypercomplex...
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