Neuronal Synchrony: A Versatile Code for the Definition of Relations?

Taking satisfactory photos under dim lighting conditions using a hand-held camera is challenging. If the camera is set to a long exposure time, the image is blurred due to camera shake. On the other hand, the image is dark and noisy if it is taken with a short exposure time but with a high camera gain. By combining information extracted from both blurred and noisy images, however, we show in this paper how to produce a high quality image that cannot be obtained by simply denoising the noisy image, or deblurring the blurred image alone. Our approach is image deblurring with the help of the noisy image. First, both images are used to estimate an accurate blur kernel, which otherwise is difficult to obtain from a single blurred image. Second, and again using both images, a residual deconvolution is proposed to significantly reduce ringing artifacts inherent to image deconvolution. Third, the remaining ringing artifacts in smooth image regions are further suppressed by a gain-controlled deconvolution process. We demonstrate the effectiveness of our approach using a number of indoor and outdoor images taken by off-the-shelf hand-held cameras in poor lighting environments.

Image deblurring with blurred/noisy image pairs

The notion of perceptual coding, which is based on the concept of distortion masking by the signal being compressed, is developed. Progress in this field as a result of advances in classical coding theory, modeling of human perception, and digital signal processing, is described. It is proposed that fundamental limits in the science can be expressed by the semiquantitative concepts of perceptual entropy and the perceptual distortion-rate function, and current compression technology is examined in that framework. Problems and future research directions are summarized. >

Signal compression based on models of human perception

Various embodiments provide systems and methods capable of facilitating interaction with handheld electronics devices based on sensing rotational rate around at least three axes and linear acceleration along at least three axes. In one aspect, a handheld electronic device includes a subsystem providing display capability, a set of motion sensors sensing rotational rate around at least three axes and linear acceleration along at least three axes, and a subsystem which, based on motion data derived from at least one of the motion sensors, is capable of facilitating interaction with the device.

Controlling and accessing content using motion processing on mobile devices

Photographs taken in low-light conditions are often blurry as a result of camera shake, i.e. a motion of the camera while its shutter is open. Most existing deblurring methods model the observed blurry image as the convolution of a sharp image with a uniform blur kernel. However, we show that blur from camera shake is in general mostly due to the 3D rotation of the camera, resulting in a blur that can be significantly non-uniform across the image. We propose a new parametrized geometric model of the blurring process in terms of the rotational motion of the camera during exposure. This model is able to capture non-uniform blur in an image due to camera shake using a single global descriptor, and can be substituted into existing deblurring algorithms with only small modifications. To demonstrate its effectiveness, we apply this model to two deblurring problems; first, the case where a single blurry image is available, for which we examine both an approximate marginalization approach and a maximum a posteriori approach, and second, the case where a sharp but noisy image of the scene is available in addition to the blurry image. We show that our approach makes it possible to model and remove a wider class of blurs than previous approaches, including uniform blur as a special case, and demonstrate its effectiveness with experiments on synthetic and real images.

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Non-uniform Deblurring for Shaken Images

A method for deblurring an image. A first image is captured. A second image is captured, wherein the second image is more blurred and more exposed than the first image. The second image is deblurred based on the first image.

Method for deblurring an image

Systems and methods for local tone mapping are provided. In one example, an electronic device includes an electronic display, an imaging device, and an image signal processor. The electronic display may display images of a first bit depth, and the imaging device may include an image sensor that obtains image data of a higher bit depth than the first bit depth. The image signal processor may process the image data, and may include local tone mapping logic that may apply a spatially varying local tone curve to a pixel of the image data to preserve local contrast when displayed on the display. The local tone mapping logic may smooth the local tone curve applied to the intensity difference between the pixel and another nearby pixel exceeds a threshold.

Systems and methods for local tone mapping

An imaging device and methods of stabilizing video captured using a rolling shutter operation. Motion estimation is used to determine a row motion vector for individual rows of a current frame of a pixel array. The row motion vectors are used to map the location of pixels in the current frame to a mapped frame representing a single acquisition time for the current frame.

Methods and system for digitally stabilizing video captured from rolling shutter cameras

This paper describes a more efficient paired comparison method that reduces the number of trials necessary for converting a table of paired comparisons into scaler data. Instead of comparing every pair of samples (the complete method), a partial method is used that makes more comparisons between closer samples than between more distant samples. A sorting algorithm is used to effi- ciently order the samples with paired comparisons, and each com- parison is recorded. When the sorting is completed, more trials will have been conducted between closer samples than between distant samples. Regression is used to scale the resulting comparison ma- trix into a one dimensional perceptual quality estimate. © 2001 SPIE

Efficient method for paired comparison

A system and method of transmitting an image adapted to a first display area size, such as a standard computer screan having a particular pixel-by-pixel resolution, to an apparatus having a smaller second display area size by scaling the image through coeffiecient cropping its frequency domiain representation. When the cropped frequency coefficients are used to display an image within the second smaller display area, a scaled version of the image is displayed. In a specific embodiment, frequency domain coefficients are cropped such that a region of interest of the image is scaled down less than the remainder of the image when displaged in the second smaller display area. Scaling in this manner provides the user with a readable region of interest with the remainder of the image scaled down so as to facilitate easy image navigation by the user.

D. Amnon Silverstein

Papers

Method for deblurring an image

Systems and methods for local tone mapping

Methods and system for digitally stabilizing video captured from rolling shutter cameras

Efficient method for paired comparison

Image transmission for low bandwidth with region of interest