Janusz Pawel Kowalski

Detection of noise in digital images by using the averaging filter name COV

One of the significant problems in digital signal processing is the filtering and reduction of undesired interference. Due to the abundance of methods and algorithms for processing signals characterized by complexity and effectiveness of removing noise from a signal, depending on the character and level of noise, it is difficult to choose the most effective method. So long as there is specific knowledge or grounds for certain assumptions as to the nature and form of the noise, it is possible to select the appropriate filtering method so as to ensure optimum quality. This chapter describes several methods for estimating the level of noise and presents a new method based on the properties of the smoothing filter.

Using the Q measure to create panoramic photographs

The authors presented a new method of creating panoramic photographs. A panoramic photograph is composed of a few images taken with a camera. The authors developed and tested an algorithm to create panoramic photographs which is based on a popular index applied in evaluation of quality of digital images using a reference image - the Universal Quality Image Index. The result of applying the suggested algorithm is an effective match of the sequence of partial digital photographs which make the panoramic photograph.

Estimation of the Level of Disturbance in Time Series Using a Median Filter

Information about the level of signal interference, allows you to select the appropriate method pre-processing information. Assuming that the disturbance is a process additive, a normal distribution can do this using the smoothing filters, and in particular the median filter. This chapter presents a method of estimating the level of disturbance, based on median filtration and the assumption that the smoothing process applies to noise, exclusively. The knowledge of a noise reduction coefficient enables the determining of an estimated quantity.

Estimation of the Amount of Noise in Digital Images Using Finite Differences

The paper presents a novel method for estimating the variance of noise in a digital image. This method is based on filtering corrupted image using finite differences. As a result an original signal is removed while noise remains so its variance can be calculated. In the paper several differential filter’s masks of various sizes were derived. The proposed method was verified on test images corrupted by the additive Gaussian distributed noise. The method was compared with several previously published estimation methods. It was shown that the novel method performs well for a large range of noise variance values.

Recognising the user's face based on algorithms using the analysis of Q measure indication for their operation

In the article, the authors presented their own method of recognising the users face. The proposed method is based on the analysis of the objective quality measure — Universal Image Quality Measure indication. The applied quality measure, except for recognising users based on the photographs of their faces, was also used in the synchronisation process preceding face recognition — it was used to find the shift as well as the rotation axis and angle between digital images.

The Use of Tuned Shape Window for the Improvement of Scars Imaging in Static Renal Scintigraphy in Children

Physiological renal processes are evaluated based on planar images registered by a gamma camera, SPECT or PET. However, detection of small disorders in standard planar scintigraphic imaging is difficult and sometimes impossible. The aim of the research conducted at Pomeranian Medical University is to increase the sensitivity of the method for detecting the areas of renal functional disorders called scarring. The image recorded as a result of the test was subject to digital processing. In that purpose, a novel window function was used for filter designing. Standard and processed images were presented to three independent experts. The diagnosis results were subject to statistical analysis. As a result, a large share of changes in diagnosis was reported in the total number of conducted tests, a strong correlation between positive evaluation of the role of processed images and a change in diagnosis as well as an increased possibility of kidney condition evaluation.

The Use of the Universal Quality Index for User Recognition Based on Fingerprint Analysis

In the article, the authors presented the possibilities of using the Universal Image Quality Index (Q)—a popular measure for evaluation of digital image quality in order to identify users based on analysing their fingerprints with the use of a reference image. The applied quality measure is used both for analysing of fingerprints as well as in the process of synchronisation preceding the analysis.

The Use of the Objective Digital Image Quality Assessment Criterion Indication to Create Panoramic Photographs

In the article, the authors presented a method of creating panoramic photographs developed by themselves. For its operation, the method uses a matching algorithm developed by the authors, which is based on the analysis of the indication of a popular digital image assessment quality measure - Universal Quality Index. The result of applying the suggested algorithm is an effective match of the sequence of partial digital photographs which make the panoramic photograph.