共查询到20条相似文献,搜索用时 15 毫秒
1.
Recognition of coloured and textured images through a multi-scale neural architecture with orientational filtering and chromatic diffusion 总被引:1,自引:0,他引:1
The aim of this paper is to outline a multiple scale neural model to recognise colour images of textured scenes. This model combines colour and textural information in order to recognise colour texture images through the operation of two main components: a segmentation component composed of the colour opponent system (COS) and the chromatic segmentation system (CSS); and a recognition component formed by an ARTMAP-based neural network with scale and orientation-invariance properties. Segmentation is achieved by perceptual contour extraction and diffusion processes on the colour opponent channels based on the human psychophysical theory of colour perception. This colour regions enhancement along with their local textural features constitutes the recognition pattern to be sent to the supervised neural classifier. The CSS accomplishes the colour region enhancement through a multiple scale loop of oriented filters and competition–cooperation mechanisms. Afterwards, the neural architecture performs an attentive recognition of the scene using those oriented filters responses and the chromatic diffusions. Some comparative tests with other models are included in order to prove the recognition capabilities of this neural architecture and how the use of colour information encourages the texture classification and the accuracy of the boundary detection. 相似文献
2.
G. Qiu 《Pattern recognition》2002,35(8):1675-1686
In this paper, we present a method to represent achromatic and chromatic image signals independently for content-based image indexing and retrieval for image database applications. Starting from an opponent colour representation, human colour vision theories and modern digital signal processing technologies are applied to develop a compact and computationally efficient visual appearance model for coloured image patterns. We use the model to compute the statistics of achromatic and chromatic spatial patterns of colour images for indexing and content-based retrieval. Two types of colour images databases, one colour texture database and another photography colour image database are used to evaluate the performance of the developed method in content-based image indexing and retrieval. Experimental results are presented to show that the new method is superior or competitive to state-of-the-art content-based image indexing and retrieval techniques. 相似文献
3.
M. Hauta-Kasari J. Parkkinen T. Jaaskelainen R. Lenz 《Pattern Analysis & Applications》1999,2(4):275-284
Multi-spectral images are becoming more common in industrial inspection tasks where the colour is used as a quality measure.
In this paper we propose a spectral cooccurrence matrix-based method to analyse multi-spectral texture images, in which every
pixel contains a measured colour spectrum. We first quantise the spectral domain of the multi-spectral images using the Self-Organising
Map (SOM). Next we label the spectral domain according to the quantised spectra. In the spatial domain, we represent a multi-spectral
texture using the spectral cooccurrence matrix, which we calculate from the labelled image. In the experimental part of this
paper, we present the results of segmenting natural multi-spectral textures. We compared the k-nearest neighbour (k-NN) classifier and the multilayer perceptron (MLP) neural network-based segmentation results of the multi-spectral and RGB
colour textures.
Received: 15 September 1998, Received in revised form: 25 January 1999, Accepted: 22 March 1999 相似文献
4.
Colour is one of the most important features in content based image retrieval. However, colour is rarely used as a feature that codes local spatial information, except for colour texture. This paper presents an approach to represent spatial colour distributions using local principal component analysis (PCA). The representation is based on image windows which are selected by two complementary data driven attentive mechanisms: a symmetry based saliency map and an edge and corner detector. The eigenvectors obtained from local PCA of the selected windows form colour patterns that capture both low and high spatial frequencies, so they are well suited for shape as well as texture representation. Projections of the windows selected from the image database to the local PCs serve as a compact representation for the search database. Queries are formulated by specifying windows within query images. System feedback makes both the search process and the results comprehensible for the user. 相似文献
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Gerald M. Murch 《Computer Graphics Forum》1985,4(2):127-135
The human visual system's capacity and capability to process colour can be applied as a design criterion for colour information displays. This paper reviews key elements in the visual domain of colour, encompassing the visual, perceptual, and cognitive modes and develops a series of recommendations for effective colour usage based on these elements. 相似文献
7.
Papathomas T.V. Kashi R.S. Gorea A. 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》1997,27(3):428-440
We have developed a computational model for texture perception which has physiological relevance and correlates well with human performance. The model attempts to simulate the visual processing characteristics by incorporating mechanisms tuned to detect luminance-polarity, orientation, spatial frequency and color, which are characteristic features of any textural image. We obtained a very good correlation between the model's simulation results and data from psychophysical experiments with a systematically selected set of visual stimuli with texture patterns defined by spatial variations in color, luminance, and orientation. In addition, the model predicts correctly texture segregation performance with key benchmarks and natural textures. This represents a first effort to incorporate chromatic signals in texture segregation models of psychophysical relevance, most of which have treated grey-level images so far. Another novel feature of the model is the extension or the concept of spatial double opponency to domains beyond color, such as orientation and spatial frequency. The model has potential applications in the areas of image processing, machine vision and pattern recognition, and scientific visualization. 相似文献
8.
Images as Embedded Maps and Minimal Surfaces: Movies,Color, Texture,and Volumetric Medical Images 总被引:11,自引:4,他引:7
We extend the geometric framework introduced in Sochen et al. (IEEE Trans. on Image Processing, 7(3):310–318, 1998) for image enhancement. We analyze and propose enhancement techniques that selectively smooth images while preserving either the multi-channel edges or the orientation-dependent texture features in them. Images are treated as manifolds in a feature-space. This geometrical interpretation lead to a general way for grey level, color, movies, volumetric medical data, and color-texture image enhancement.We first review our framework in which the Polyakov action from high-energy physics is used to develop a minimization procedure through a geometric flow for images. Here we show that the geometric flow, based on manifold volume minimization, yields a novel enhancement procedure for color images. We apply the geometric framework and the general Beltrami flow to feature-preserving denoising of images in various spaces.Next, we introduce a new method for color and texture enhancement. Motivated by Gabor's geometric image sharpening method (Gabor, Laboratory Investigation, 14(6):801–807, 1965), we present a geometric sharpening procedure for color images with texture. It is based on inverse diffusion across the multi-channel edge, and diffusion along the edge. 相似文献
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I. Foucherot Author Vitae Author Vitae J.C. Devaux Author VitaeAuthor Vitae 《Pattern recognition》2004,37(8):1661-1674
In this article, we offer an original study on the analysis of the texture of colour images based on Local Linear Transforms (LLT). Our colour approach is based on the separability of the data which reduces the number of texture parameters. We also propose the extension of Run Lengths (RL) and Co-occurrence Matrixes (CM) to colour images. In this respect, two different ways were explored (data merging and quantification). We finally present a comparative study showing the efficiency of the first method (LLT) as well as the complementary nature of the other methods (RL, CM). 相似文献
11.
Measured reflection data such as the bidirectional texture function (BTF) represent spatial variation under the full hemisphere of view and light directions and offer a very realistic visual appearance. Despite its high‐dimensional nature, recent compression techniques allow rendering of BTFs in real time. Nevertheless, a still unsolved problem is that there is no representation suited for real‐time rendering that can be used by designers to modify the BTF's appearance. For intuitive editing, a set of low‐dimensional comprehensible parameters, stored as scalars, colour values or texture maps, is required. In this paper we present a novel way to represent BTF data by introducing the geometric BRDF (g‐BRDF), which describes both the underlying meso‐ and micro‐scale structure in a very compact way. Both are stored in texture maps with only a few additional scalar parameters that can all be modified at runtime and thus give the designer full control over the material's appearance in the final real‐time application. The g‐BRDF does not only allow intuitive editing, but also reduces the measured data into a small set of textures, yielding a very effective compression method. In contrast to common material representation combining heightfields and BRDFs, our g‐BRDF is physically based and derived from direct measurement, thus representing real‐world surface appearance. In addition, we propose an algorithm for fully automatic decomposition of a given measured BTF into the g‐BRDF representation. 相似文献
12.
In industrial quality inspection of colour texture surfaces, such as ceramic tiles or fabrics, it is important to maintain a consistent colour shade or tonality during production. We present a multidimensional histogram method using a novelty detection scheme to inspect the surfaces. The image noise, introduced by the imaging system, is found mainly to affect the chromatic channels. For colour tonality inspection, the difference between images is very subtle and comparison in the noise dominated chromatic channels is error prone. We perform vector-ordered colour smoothing and extract a localised feature vector at each pixel. The resulting histogram represents an encapsulation of local and global information. Principal component analysis (PCA) is performed on this multidimensional feature space of an automatically selected reference image to obtain reliable colour shade features, which results in a reference eigenspace. Then unseen product images are projected onto this eigenspace and compared for tonality defect detection using histogram comparison. The proposed method is compared and evaluated on a data set with groundtruth.
Xianghua Xie is currently a Ph.D. student and a research assistant in the Department of Computer Science, University of Bristol, U.K. Prior to this, he received an M.Sc. degree in advanced computing with commendation from the University of Bristol in 2002 and a B.Sc. degree in environmental engineering from the Tongji University, Shanghai, P.R. China, in 2000. His current research interests are texture analysis, image segmentation, surface inspection, deformable models and historical document analysis. He is a student member of the BMVA, the IEE and the IEEE.
Majid Mirmehdi received the B.Sc. (Hons.) and Ph.D. degrees in computer science in 1985 and 1991 respectively, from the City University, London. He has worked both in industry and in academia. He is currently a Reader in the Department of Computer Science at the University of Bristol, UK. His research interests include texture analysis, colour image analysis, medical imaging and document recognition. He has over 100 refereed conference and journal publications in these areas. He is an associate editor of the Pattern Analysis and Applications Journal. He is a member of the IEE, IEEE and a member and the Chairman of the British Machine Vision Association. 相似文献
13.
Image fusion is a process that multiple images of a scene are combined to form a single image. The aim of image fusion is
to preserve the full content and retain important features of each original image. In this paper, we propose a novel approach
based on wavelet transform to capture and fusion of real-world rough surface textures, which are commonly used in multimedia
applications and referred to as3D surface texture. These textures are different from 2D textures as their appearances can
vary dramatically with different illumination conditions due to complex surface geometry and reflectance properties. In our
approach, we first extract gradient/height and albedo maps from sample 3D surface texture images as their representation.
Then we measure saliency of wavelet coefficients of these 3D surface texture representations. The saliency values reflect
the meaningful content of the wavelet coefficients and are consistent with human visual perception. Finally we fuse the gradient/height
and albedo maps based on the measured saliency values. This novel scheme aims to preserve the original texture patterns together
with geometry and reflectance characteristics from input images. Experimental results show that the proposed approach can
not only capture and fuse 3D surface texture under arbitrary illumination directions, but also has the ability to retain the
surface geometry properties and preserve perceptual features in the original images. 相似文献
14.
A system is presented for characterizing anomalous colour observers according to the type of colour vision deficiency that they suffer. The system is based on the simulation of a Pickford–Nicholson type anomaloscope using a cathode ray tube and a personal computer. By means of this method, it has been possible to determine the type of deficiency of the red–green chromatic channel presented by various anomalous observers. 相似文献
15.
Image Registration Using Wavelet-Based Motion Model 总被引:2,自引:0,他引:2
Yu-Te Wu Takeo Kanade Ching-Chung Li Jeffrey Cohn 《International Journal of Computer Vision》2000,38(2):129-152
An image registration algorithm is developed to estimate dense motion vectors between two images using the coarse-to-fine wavelet-based motion model. This motion model is described by a linear combination of hierarchical basis functions proposed by Cai and Wang (SIAM Numer. Anal., 33(3):937–970, 1996). The coarser-scale basis function has larger support while the finer-scale basis function has smaller support. With these variable supports in full resolution, the basis functions serve as large-to-small windows so that the global and local information can be incorporated concurrently for image matching, especially for recovering motion vectors containing large displacements. To evaluate the accuracy of the wavelet-based method, two sets of test images were experimented using both the wavelet-based method and a leading pyramid spline-based method by Szeliski et al. (International Journal of Computer Vision, 22(3):199–218, 1996). One set of test images, taken from Barron et al. (International Journal of Computer Vision, 12:43–77, 1994), contains small displacements. The other set exhibits low texture or spatial aliasing after image blurring and contains large displacements. The experimental results showed that our wavelet-based method produced better motion estimates with error distributions having a smaller mean and smaller standard deviation. 相似文献
16.
In this paper, we proposed a new speech enhancement system, which integrates a perceptual filterbank and minimum mean square error–short time spectral amplitude (MMSE–STSA) estimation, modified according to speech presence uncertainty. The perceptual filterbank was designed by adjusting undecimated wavelet packet decomposition (UWPD) tree, according to critical bands of psycho-acoustic model of human auditory system. The MMSE–STSA estimation (modified according to speech presence uncertainty) was used for estimation of speech in undecimated wavelet packet domain. The perceptual filterbank provides a good auditory representation (sufficient frequency resolution), good perceptual quality of speech and low computational load. The MMSE–STSA estimator is based on a priori SNR estimation. A priori SNR estimation, which is a key parameter in MMSE–STSA estimator, was performed by using “decision directed method.” The “decision directed method” provides a trade off between noise reduction and signal distortion when correctly tuned. The experiments were conducted for various noise types. The results of proposed method were compared with those of other popular methods, Wiener estimation and MMSE–log spectral amplitude (MMSE–LSA) estimation in frequency domain. To test the performance of the proposed speech enhancement system, three objective quality measurement tests (SNR, segSNR and Itakura–Saito distance (ISd)) were conducted for various noise types and SNRs. Experimental results and objective quality measurement test results proved the performance of proposed speech enhancement system. The proposed speech enhancement system provided sufficient noise reduction and good intelligibility and perceptual quality, without causing considerable signal distortion and musical background noise. 相似文献
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A Parametric Texture Model Based on Joint Statistics of Complex Wavelet Coefficients 总被引:27,自引:0,他引:27
We present a universal statistical model for texture images in the context of an overcomplete complex wavelet transform. The model is parameterized by a set of statistics computed on pairs of coefficients corresponding to basis functions at adjacent spatial locations, orientations, and scales. We develop an efficient algorithm for synthesizing random images subject to these constraints, by iteratively projecting onto the set of images satisfying each constraint, and we use this to test the perceptual validity of the model. In particular, we demonstrate the necessity of subgroups of the parameter set by showing examples of texture synthesis that fail when those parameters are removed from the set. We also demonstrate the power of our model by successfully synthesizing examples drawn from a diverse collection of artificial and natural textures. 相似文献