Results 1 - 10 of 2,316

Nonlinear total variation based noise removal algorithms

by Leonid I. Rudin, Stanley Osher, Emad Fatemi , 1992
"... A constrained optimization type of numerical algorithm for removing noise from images is presented. The total variation of the image is minimized subject to constraints involving the statistics of the noise. The constraints are imposed using Lagrange multipliers. The solution is obtained using the g ..."
Abstract - Cited by 2271 (51 self) - Add to MetaCart
to be state-of-the-art for very noisy images. The method is noninvasive, yielding sharp edges in the image. The technique could be interpreted as a first step of moving each level set of the image normal to itself with velocity equal to the curvature of the level set divided by the magnitude of the gradient

Scale-space and edge detection using anisotropic diffusion

by Pietro Perona, Jitendra Malik - IEEE Transactions on Pattern Analysis and Machine Intelligence , 1990
"... Abstract-The scale-space technique introduced by Witkin involves generating coarser resolution images by convolving the original image with a Gaussian kernel. This approach has a major drawback: it is difficult to obtain accurately the locations of the “semantically mean-ingful ” edges at coarse sca ..."
Abstract - Cited by 1887 (1 self) - Add to MetaCart
that the “no new maxima should be generated at coarse scales ” property of conventional scale space is pre-served. As the region boundaries in our approach remain sharp, we obtain a high quality edge detector which successfully exploits global information. Experimental results are shown on a number of images

Example-based super-resolution

by William T. Freeman, Thouis R. Jones, Egon C. Pasztor - IEEE COMPUT. GRAPH. APPL , 2001
"... The Problem: Pixel representations for images do not have resolution independence. When we zoom into a bitmapped image, we get a blurred image. Figure 1 shows the problem for a teapot image, rich with real-world detail. We know the teapot’s features should remain sharp as we zoom in on them, yet sta ..."
Abstract - Cited by 349 (5 self) - Add to MetaCart
The Problem: Pixel representations for images do not have resolution independence. When we zoom into a bitmapped image, we get a blurred image. Figure 1 shows the problem for a teapot image, rich with real-world detail. We know the teapot’s features should remain sharp as we zoom in on them, yet

Image and depth from a conventional camera with a coded aperture

by Anat Levin, Rob Fergus, Frédo Durand, William T. Freeman - ACM TRANS. GRAPH , 2007
"... A conventional camera captures blurred versions of scene information away from the plane of focus. Camera systems have been proposed that allow for recording all-focus images, or for extracting depth, but to record both simultaneously has required more extensive hardware and reduced spatial resolut ..."
Abstract - Cited by 278 (24 self) - Add to MetaCart
photographs taken with the modified camera. A layered depth map is then extracted, requiring user-drawn strokes to clarify layer assignments in some cases. The resulting sharp image and layered depth map can be combined for various photographic applications, including automatic scene segmentation, post

Edge Detection and Ridge Detection with Automatic Scale Selection

by Tony Lindeberg - CVPR'96 , 1996
"... When extracting features from image data, the type of information that can be extracted may be strongly dependent on the scales at which the feature detectors are applied. This article presents a systematic methodology for addressing this problem. A mechanism is presented for automatic selection of ..."
Abstract - Cited by 347 (24 self) - Add to MetaCart
When extracting features from image data, the type of information that can be extracted may be strongly dependent on the scales at which the feature detectors are applied. This article presents a systematic methodology for addressing this problem. A mechanism is presented for automatic selection

Chicken Cam: Sharp Images from a Moving Camera Anonymous MIT Student

by unknown authors
"... If there is any relative movement between subject and camera during the imaging formation process, the resulting image will be motion blurred. There are many different ways to reduce or eliminate motion blur, each with its own set of complexities and tradeoffs. The simplest way to avoid blur is to p ..."
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If there is any relative movement between subject and camera during the imaging formation process, the resulting image will be motion blurred. There are many different ways to reduce or eliminate motion blur, each with its own set of complexities and tradeoffs. The simplest way to avoid blur

Negative refraction makes a perfect lens

by Jb Pendry - Phys. Rev. Lett , 2000
"... With a conventional lens sharpness of the image is always limited by the wavelength of light. An unconventional alternative to a lens, a slab of negative refractive index material, has the power to focus all Fourier components of a 2D image, even those that do not propagate in a radiative manner. Su ..."
Abstract - Cited by 292 (3 self) - Add to MetaCart
With a conventional lens sharpness of the image is always limited by the wavelength of light. An unconventional alternative to a lens, a slab of negative refractive index material, has the power to focus all Fourier components of a 2D image, even those that do not propagate in a radiative manner

Fast and Robust Multi-Frame Super-Resolution

by Sina Farsiu, Dirk Robinson, Michael Elad, Peyman Milanfar - IEEE Transactions on Image ProcessinG , 2003
"... In the last two decades, many papers have been published, proposing a variety of methods for multi- frame resolution enhancement. These methods are usually very sensitive to their assumed model of data and noise, which limits their utility. This paper reviews some of these methods and addresses th ..."
Abstract - Cited by 272 (37 self) - Add to MetaCart
their shortcomings. We propose an alternate approach using L norm minimization and robust regularization based on a bilateral prior to deal with different data and noise models. This computationally inexpensive method is robust to errors in motion and blur estimation, and results in images with sharp edges.

PSF estimation using sharp edge prediction

by Neel Joshi, Richard Szeliski, David J. Kriegman - In IEEE Conference on Computer Vision and Pattern Recognition , 2008
"... Image blur is caused by a number of factors such as motion, defocus, capturing light over the non-zero area of the aperture and pixel, the presence of anti-aliasing filters on a camera sensor, and limited sensor resolution. We present an algorithm that estimates non-parametric, spatially-varying blu ..."
Abstract - Cited by 107 (4 self) - Add to MetaCart
-pixel, super-resolved PSF even for in-focus images. It operates by predicting a “sharp ” version of a blurry input image and uses the two images to solve for a PSF. We handle the cases where the scene content is unknown and also where a known printed calibration target is placed in the scene. Our method

Sharpness rules

by Garrett M. Johnson, Mark D. Fairchild - Proc of IS&T/SID 8 th Color Imaging Conference , 2000
"... A large-scale psychophysical experiment was performed examining the effects of various simultaneous variations of image parameters on perceived image sharpness. The goal of this experiment was to unlock some of the rules of image sharpness perception. A paired comparison paradigm was used to compare ..."
Abstract - Cited by 8 (2 self) - Add to MetaCart
A large-scale psychophysical experiment was performed examining the effects of various simultaneous variations of image parameters on perceived image sharpness. The goal of this experiment was to unlock some of the rules of image sharpness perception. A paired comparison paradigm was used
Results 1 - 10 of 2,316