image interpolation is an important image operation. It is commonly used in image enlargement to obtain a close-up view of the detail of an image. From sampling theory, an ideal low-pass filter can be used for image i...
详细信息
作者:
Chen, HongFord, Gary E.CIPIC
Center for Image Processing and Integrated Computing University of California DavisCA95616 United States
We propose a perceptual Wiener filter for image restoration, a linear space-variant filter which accounts for the human visual system response to image details and noise in the vicinity of an edge. This filter provide...
详细信息
作者:
El-Fallah, Adel I.Ford, Gary E.CIPIC
Center for Image Processing and Integrated Computing University of California Davis DavisCA95616 United States
We propose a geometrical surface representation for an image, and introduce a nonlinear adaptive filter that diffuses the surface in time at a speed proportional to the mean curvature. Linear variations in intensity (...
详细信息
This paper presents a method to preprocess an image so that when segmented it yields a partitioning in which textured regions are approximated with a substantially reduced number of uniform regions (which is desirable...
详细信息
Proposes a perceptual Wiener filter for image restoration, a linear space-variant filter which accounts for the human visual system response to image details and noise in the vicinity of an edge. This filter provides ...
详细信息
Proposes a perceptual Wiener filter for image restoration, a linear space-variant filter which accounts for the human visual system response to image details and noise in the vicinity of an edge. This filter provides a reduction in the ringing artifact observed in the vicinity of edges, when compared to the response of the widely used linear space-invariant classical Wiener filter. A fast, approximate implementation of the filter is discussed.< >
A new formulation for inhomogeneous image diffusion is presented in which the image is regarded as a surface in 3-space. The evolution of this surface under diffusion is analyzed by classical methods of differential g...
详细信息
A new formulation for inhomogeneous image diffusion is presented in which the image is regarded as a surface in 3-space. The evolution of this surface under diffusion is analyzed by classical methods of differential geometry. A nonlinear filtering theory is introduced in which only the divergence of the direction of the surface gradient is averaged. This averaging preserves edges and lines, as their direction is non-divergent, while noise is averaged since it does not have non-divergent consistency. Our approach achieves this objective by evolving the surface at a speed proportional to mean curvature leading to the minimization of the surface area and the imposition of regularity everywhere. Furthermore, we introduce a new filter that renders corners, as well as edges, invariant to the diffusion process. Experiments demonstrating the adequacy of this new theory are presented.< >
作者:
A.I. El-FallahG.E. FordCIPIC
Center for Image Processing and Integrated Computing University of California Davis CA USA
Proposes a geometrical surface representation for an image, and introduces a nonlinear adaptive filter that diffuses the surface in time at a speed proportional to the mean curvature. Linear variations in intensity (e...
详细信息
Proposes a geometrical surface representation for an image, and introduces a nonlinear adaptive filter that diffuses the surface in time at a speed proportional to the mean curvature. Linear variations in intensity (edges) are inclined planes of vanishing mean curvature, and are thus invariant. Noise is characterized by high mean curvature and will be diffused. The authors show that this diffusion resolves the conflict of removing noise while preserving edges. A novel nonlinear scale space filtering relating surface area to the diffusion speed is introduced resulting in very efficient algorithms. Experiments demonstrating excellent performance and efficiency are presented.< >
image interpolation is an important image operation. It is commonly used in image enlargement to obtain a close-up view of the detail of an image. From sampling theory, an ideal low-pass filter can be used for image i...
详细信息
image interpolation is an important image operation. It is commonly used in image enlargement to obtain a close-up view of the detail of an image. From sampling theory, an ideal low-pass filter can be used for image interpolation. However, ripples appear around image edges which are annoying to a human viewer. The authors introduce a new FIR image interpolation filter known as a perceptually weighted least square (PWLS) filter which is designed using both sampling theory and properties of human vision. The goal of this design approach is to minimize the ripple response around edges of the interpolated images and to best satisfy frequency response constraints. The interpolation results using the proposed approach are substantially better than those resulting from replication or bilinear interpolation, and are at least as good as and possibly better than that of cubic convolution interpolation.< >
This paper presents a method to preprocess an image so that when segmented it yields a partitioning in which textured regions are approximated with a substantially reduced number of uniform regions (which is desirable...
详细信息
This paper presents a method to preprocess an image so that when segmented it yields a partitioning in which textured regions are approximated with a substantially reduced number of uniform regions (which is desirable for the coding). The segmentation method used to form this representation combines a Gaussian texture model and Gibbs-Markov contour model in order to find regions with boundaries which correspond closely to the objects in the image. Given the image segmentation, an approximation to the original image is generated by filling each region with its mean value. If higher quality reconstruction is desired, the quantized approximation error is also encoded. In order to exploit the reduced sensitivity of the human visual system to the error around edges (visual masking), the error is quantized using three nonlinear quantizers corresponding to the smoothly varying, textured, and remaining areas of the image, respectively.< >
A maximum likelihood estimation (MLE) method is used to estimate the fractal dimension of a number of natural texture images with and without the presence of noise. An additional texture measure which can be linked to...
详细信息
暂无评论