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The Design and Use of Steerable Filters
 IEEE Transactions on Pattern Analysis and Machine Intelligence
, 1991
"... Oriented filters are useful in many early vision and image processing tasks. One often needs to apply the same filter, rotated to different angles under adaptive control, or wishes to calculate the filter response at various orientations. We present an efficient architecture to synthesize filters of ..."
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Cited by 1047 (12 self)
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Oriented filters are useful in many early vision and image processing tasks. One often needs to apply the same filter, rotated to different angles under adaptive control, or wishes to calculate the filter response at various orientations. We present an efficient architecture to synthesize filters of arbitrary orientations from linear combinations of basis filters, allowing one to adaptively "steer" a filter to any orientation, and to determine analytically the filter output as a function of orientation.
Perceptual image distortion
 In Proceedings of SPIE
, 1994
"... In this paper, we present a perceptual distortion measure that predicts image integrity far better than meansquared error. This perceptual distortion measure is based on a model of human visual processing that ts empirical measurements of the psychophysics of spatial pattern detection. The model of ..."
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Cited by 170 (0 self)
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In this paper, we present a perceptual distortion measure that predicts image integrity far better than meansquared error. This perceptual distortion measure is based on a model of human visual processing that ts empirical measurements of the psychophysics of spatial pattern detection. The model of human visual processing proposed involves two major components: a steerable pyramid transform and contrast normalization. We also illustrate the usefulness of the model in predicting perceptual distortion in real images. 1.
Issues in Vision Modeling for Perceptual Video Quality Assessment
, 1999
"... Lossy compression algorithms used in digital video systems produce artifacts whose visibility strongly depends on the actual image content. Simple error measures such as RMSE or PSNR, albeit popular, ignore this important fact and are only a mediocre predictor of perceived quality. Many applications ..."
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Cited by 77 (11 self)
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Lossy compression algorithms used in digital video systems produce artifacts whose visibility strongly depends on the actual image content. Simple error measures such as RMSE or PSNR, albeit popular, ignore this important fact and are only a mediocre predictor of perceived quality. Many applications require more reliable assessment methods. This paper discusses issues in vision modeling for perceptual video quality assessment (PVQA). Its purpose is not to describe a particular model or system, but rather to summarize and to provide pointers to uptodate knowledge of important characteristics of the human visual system, to explain how these characteristics may be incorporated in vision models for PVQA, to give a brief overview of the stateoftheart and current efforts in this field, and to outline directions for future research.
Subband Transforms
, 1990
"... this paper, the boxes H i #!# indicate circular convolution of a #nite input image of size N with a #lter with impulse response h i #n# and Fourier transform ..."
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Cited by 33 (8 self)
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this paper, the boxes H i #!# indicate circular convolution of a #nite input image of size N with a #lter with impulse response h i #n# and Fourier transform
Steerable Filters and Local Analysis of Image Structure
, 1992
"... Two paradigms for visual analysis are topdown, starting from highlevel models or information about the image, and bottomup, where little is assumed about the image or objects in it. We explore a local, bottomup approach to image analysis. We develop operators to identify and classify image junct ..."
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Cited by 29 (0 self)
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Two paradigms for visual analysis are topdown, starting from highlevel models or information about the image, and bottomup, where little is assumed about the image or objects in it. We explore a local, bottomup approach to image analysis. We develop operators to identify and classify image junctions, whichcontain important visual cues for identifying occlusion, transparency, and surface bends. Like the human visual system, we begin with the application of linear filters which are oriented in all possible directions. Wedevelop an efficientway to create an oriented filter of arbitrary orientation by describing it as a linear combination of basis filters. This approach to oriented filtering, which we call steerable filters, offers advantages for analysis as well as computation. We design a variety of steerable filters, including steerable quadrature pairs, which measure local energy. We show applications of these filters in orientation and texture analysis, and image representation and enhanc...
FIR Filter Banks for Hexagonal Data Processing
"... Abstract—Images are conventionally sampled on a rectangular lattice. Thus, traditional image processing is carried out on the rectangular lattice. The hexagonal lattice was proposed more than four decades ago as an alternative method for sampling. Compared with the rectangular lattice, the hexagonal ..."
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Cited by 5 (4 self)
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Abstract—Images are conventionally sampled on a rectangular lattice. Thus, traditional image processing is carried out on the rectangular lattice. The hexagonal lattice was proposed more than four decades ago as an alternative method for sampling. Compared with the rectangular lattice, the hexagonal lattice has certain advantages which include that it needs less sampling points; it has better consistent connectivity and higher symmetry; the hexagonal structure is also pertinent to the vision process. In this paper we investigate the construction of symmetric FIR hexagonal filter banks for multiresolution hexagonal image processing. We obtain block structures of FIR hexagonal filter banks with 3fold rotational symmetry and 3fold axial symmetry. These block structures yield families of orthogonal and biorthogonal FIR hexagonal filter banks with 3fold rotational symmetry and 3fold axial symmetry. In this paper, we also discuss the construction of orthogonal and biorthogonal FIR filter banks with scaling functions and wavelets having optimal smoothness. In addition, we present a few of such orthogonal and biorthogonal FIR filters banks. Index Terms—Hexagonal lattice, hexagonal data, 3fold rotational symmetry, 3fold axial symmetry, orthogonal and biorthogonal FIR hexagonal filter banks, orthogonal and biorthogonal hexagonal wavelets. EDICS Category: MRPFBNK I.
Efficient Implementation of Deformable Filter Banks
, 1997
"... This paper describes efficientschemes for the computation of a large number of differentely scaled/oriented filtered versions of an image. We generalize the wellknown steerable/scalable ("deformable") filter bank structure by imposing XY separability on the basis filters. This systems, ..."
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Cited by 5 (2 self)
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This paper describes efficientschemes for the computation of a large number of differentely scaled/oriented filtered versions of an image. We generalize the wellknown steerable/scalable ("deformable") filter bank structure by imposing XY separability on the basis filters. This systems, designed by an iterative projections technique, achieve substantial reduction of the computational cost.
Orthogonal and biorthogonal FIR hexagonal filter banks with sixfold symmetry
 IEEE Trans. Signal Proc
, 2008
"... Abstract—Recently hexagonal image processing has attracted attention. The hexagonal lattice has several advantages in comparison with the rectangular lattice, the conventionally used lattice for image sampling and processing. For example, a hexagonal lattice needs fewer sampling points; it has bette ..."
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Cited by 2 (2 self)
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Abstract—Recently hexagonal image processing has attracted attention. The hexagonal lattice has several advantages in comparison with the rectangular lattice, the conventionally used lattice for image sampling and processing. For example, a hexagonal lattice needs fewer sampling points; it has better consistent connectivity; it has higher symmetry; its structure is plausible to human vision systems. The multiresolution analysis method has been used for hexagonal image processing. Since the hexagonal lattice has high degree of symmetry, it is desirable that the hexagonal lter banks designed for multiresolution hexagonal image processing also have high order of symmetry which is pertinent to the symmetry structure of the hexagonal lattice. The orthogonal or prefect reconstruction (PR) hexagonal lter banks which are available in the literature have only 3fold symmetry. In this paper we investigate the construction of orthogonal and PR FIR hexagonal lter banks with 6fold symmetry. We obtain block structures of 7size re nement (7channel 2D) orthogonal and PR FIR hexagonal lter banks with 6fold rotational symmetry. √ 7re nement orthogonal and biorthogonal wavelets based on these block structures are constructed. In this paper, we also consider FIR hexagonal lter banks with axial (line) symmetry, and we present a block structure of FIR hexagonal lter banks with pseudo 6fold axial symmetry. Index Terms—Hexagonal lattice, hexagonal image, lter bank with 6fold symmetry, orthogonal hexagonal lter bank, biorthogonal hexagonal lter bank, √ 7re nement wavelet, 7size re nement multiresolution decomposition/reconstruction. EDICS Category: MRPFBNK I.
unknown title
"... this paper, the boxes H i #!# indicate circular convolution of a #nite input image of size N with a #lter with impulse response h i #n# and Fourier transform H i #!#= h i #n#e #j!n We do not place a causality constraint on the #lter impulse responses, since they are meant for application to im ..."
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this paper, the boxes H i #!# indicate circular convolution of a #nite input image of size N with a #lter with impulse response h i #n# and Fourier transform H i #!#= h i #n#e #j!n We do not place a causality constraint on the #lter impulse responses, since they are meant for application to images. We do, however, assume that the region of support of the #lter is smaller than the image size. The boxes k i indicate that the sequence is subsampled by a factor of k i where k i is an integer for all i. The boxes k i indicate that the sequence should be upsampled by inserting k i 1 zeros between each sample. We will assume that the integers k i are divisors of N
Subband Transforms
"... Linear transforms are the basis for many techniques used in image processing, image analysis, and image coding. Subband transforms are a subclass of linear transforms which o er useful properties for these applications. In this chapter, we discuss a variety ofsubband decompositions and illustrate th ..."
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Linear transforms are the basis for many techniques used in image processing, image analysis, and image coding. Subband transforms are a subclass of linear transforms which o er useful properties for these applications. In this chapter, we discuss a variety ofsubband decompositions and illustrate their use in image coding. Traditionally, coders based on linear transforms are divided into two categories: transform coders and subband coders. This distinction is due in part to the nature of the computational methods used for the two types of representation. Transform coding techniques are usually based on orthogonal linear transforms. The classic example of such atransform is the discrete Fourier transform (DFT), which decomposes a signal into sinusoidal frequency components. Two other examples are the discrete cosine transform (DCT) and the KarhunenLoeve transform (KLT). Conceptually, these transforms are computed by taking the inner product of the nitelength signal with a set of basis functions. This produces a set of coe cients, which are then passed on to the