In this paper is evaluated the effect of image enhancement filters on the watermark detection rate. State-of-the-art watermarking methods are still very sensitive to complex degradation attack such as print-scan process, so the detection rate of a watermark method decreases considerably after such an attack on a watermarked image. Therefore, to improve the detection rate, the degradation of the...

In this paper, a novel remote sensing image enhancement technique based on a non-local means filter in a nonsubsampled contourlet transform (NSCT) domain is proposed. The overall flow of the approach can be divided into the following steps: Firstly, the image is decomposed into one low-frequency sub-band and several high-frequency sub-bands with NSCT. Secondly, contrast stretching is adopted to...

Image enhancement for the better quality of image is required in various image based application. One of the technique to enhance the image is image fusion. It is an effective way for optimum utilization of large volumes of images from multiple sources. It extracts complete information from source images into the result, without introducing any artifacts or inconsistencies. In this process, it ...

The vertical profiles of disc galaxies are built by the material trapped around stable periodic orbits, which form their “skeletons”. According to this, the knowledge of the stability of the main families of periodic orbits in appropriate 3D models, can predict possible morphologies for edge-on disc galaxies. In a pilot survey we compare the orbital structures which lead to the appearance of “p...

In this paper we use multiscale characteristics of wavelet decompositions and their relationship to smoothness spaces such as Besov spaces to derive a framework for smoothing and sharpening of signals and images. As a result, we derive a multiscale generalization of traditional techniques, such as unsharp masking, while using the smoothness parameter α in the Besov space Bα q (L p) to provide a...

We present a fast and simple method to compute bundled layouts of general graphs. For this, we first transform a given graph drawing into a density map using kernel density estimation. Next, we apply an image sharpening technique which progressively merges local height maxima by moving the convolved graph edges into the height gradient flow. Our technique can be easily and efficiently implement...

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 images of different resolution, contrast, noise, and sharpening. In total, 50 people performed o...

Sharpness maximisation is a method that can be used to correct phase errors in images. In this paper we present a new recursive method to estimate the phase correction required for maximum image sharpness using the square of image pixel intensity metric S2. This method avoids the optimisation step required by other image sharpening approaches. We also present a similar algorithm based on the so...

We address the problem of communicating contrasts in images degraded with respect to their original due to processing with computer graphics algorithms. Such degradation can happen during the tone mapping of high dynamic range images, or while rendering scenes with low contrast shaders or with poor lighting. Inspired by a family of known perceptual illusions: Craik-O’Brien-Cornsweet, we enhance...

With general purpose denoisers approaching performance limits, we turn our attention to methods targeted to specific tasks or image classes. Using the recent plug-and-play (PnP) framework, we plug a denoiser based on Gaussian mixture models (GMM) into the iterations of an alternating direction method of multipliers (ADMM), to tackle a data fusion problem known as image sharpening. Results show ...