Introduction to computer image processing

Theoretical backgrounds and digital techniques for a class of image processing problems are presented. Image formation in the context of linear system theory, image evaluation, noise characteristics, mathematical operations on image and their implementation are discussed. Various techniques for image restoration and image enhancement are presented. Methods for object extraction and the problem of pictorial pattern recognition and classification are discussed

An Optimal Region Of Interest Localization Using Edge Refinement Filter And Entropy-Based Measurement For Point Spread Function Stimation

The use of edges to determine an optimal region of interest (ROI) location is increasingly becoming popular for image deblurring. Recent studies have shown that regions with strong edges tend to produce better deblurring results. In this study, a direct method for ROI localization based on edge refinement filter and entropy-based measurement is proposed. Using this method, the randomness of grey level distribution is quantitatively measured, from which the ROI is determined. This method has low computation cost since it contains no matrix operations. The proposed method has been tested using three sets of test images - Dataset I, II and III. Empirical results suggest that the improved edge refinement filter is competitive when compared to the established edge detection schemes and achieves better performance in the Pratt's figure-of-merit (PFoM) and the twofold consensus ground truth (TCGT); averaging at 15.7 % and 28.7 %, respectively. The novelty of the proposed approach lies in the use of this improved filtering strategy for accurate estimation of point spread function (PSF), and hence, a more precise image restoration. As a result, the proposed solutions compare favourably against existing techniques with the peak signal-to-noise ratio (PSNR), kernel similarity (KS) index, and error ratio (ER) averaging at 24.8 dB, 0.6 and 1.4, respectively. Additional experiments involving real blurred images demonstrated the competitiveness of the proposed approach in performing restoration in the absent of PSF

Colour morphological sieves for scale-space image processing

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Mathematische morfologie in de beeldverwerking Mathematical Morphology in Image Processing

Het verwerken van een afbeelding met de computer laat ons toe de kwaliteit van dit beeld te verbeteren, specifieke objecten uit het beeld te segmenteren, of extra informatie tevoorschijn te halen. Mathematische morfologie is een set van wiskundige technieken uit de beeldverwerking die ons toelaat (de vormen in) beelden te analyseren. Dit proefschrift levert oplossingen voor een aantal problemen uit de beeldverwerking, met behulp van mathematische morfologie. Morfologie toepassen op zwart-wit- of grijswaardenbeelden is relatief eenvoudig, maar de theorie uitbreiden voor kleurbeelden stelt een aantal problemen. Aangezien een kleurbeeld veel meer nuttige informatie kan bevatten dan een grijswaardenbeeld, is zo'n uitbreiding wenselijk. We stellen het meerderheidsordeningsschema (MSS) voor, wat ons toelaat kleuren onderling te ordenen op een logische manier. Morfologische beeldverwerking met kleuren wordt dan mogelijk. Een ander onderzoek betreft polymeren en composieten. Deze materialen worden als glijlagers gebruikt in allerhande voorwerpen, zoals huishoudtoestellen, sluizen, poorten, etc. Vandaar dat de studie van de slijtage hiervan belangrijk is. We gaan na of het morfologische patroonspectrum, alsook vergelijkbare technieken, een bijdrage kan leveren aan het wrijvingsonderzoek van dergelijke materialen. Dit zou de snelheid en efficiëntie van de analyses kunnen verbeteren. We merken op dat de spectrale parameters interessante verbanden vertonen met de parameters van de proefopstelling. Het derde luik van de thesis betreft het ontwikkelen van een interpolatietechniek voor zwart-wit-beelden, gebaseerd op mathematische morfologie, genaamd mmINT. Interpolatie is nodig wanneer we wensen in te zoomen op een beeld of de resolutie van het beeld willen vergroten. Dit kan van pas komen wanneer we ingescande of gedownloade tekeningen van slechte kwaliteit (te lage resolutie) willen verbeteren. mmINT werkt aanzienlijk beter dan bestaande methodes. We ontwikkelden ook een snelle variant, mmINTone, en een uitbreiding voor grijswaardenbeelden, mmINTg

Automatic Screening and Classification of Diabetic Retinopathy Eye Fundus Image

Diabetic Retinopathy (DR) is a disorder of the retinal vasculature. It develops to some degree in nearly all patients with long-standing diabetes mellitus and can result in blindness. Screening of DR is essential for both early detection and early treatment. This thesis aims to investigate automatic methods for diabetic retinopathy detection and subsequently develop an effective system for the detection and screening of diabetic retinopathy. The presented diabetic retinopathy research involves three development stages. Firstly, the thesis presents the development of a preliminary classification and screening system for diabetic retinopathy using eye fundus images. The research will then focus on the detection of the earliest signs of diabetic retinopathy, which are the microaneurysms. The detection of microaneurysms at an early stage is vital and is the first step in preventing diabetic retinopathy. Finally, the thesis will present decision support systems for the detection of diabetic retinopathy and maculopathy in eye fundus images. The detection of maculopathy, which are yellow lesions near the macula, is essential as it will eventually cause the loss of vision if the affected macula is not treated in time. An accurate retinal screening, therefore, is required to assist the retinal screeners to classify the retinal images effectively. Highly efficient and accurate image processing techniques must thus be used in order to produce an effective screening of diabetic retinopathy. In addition to the proposed diabetic retinopathy detection systems, this thesis will present a new dataset, and will highlight the dataset collection, the expert diagnosis process and the advantages of the new dataset, compared to other public eye fundus images datasets available. The new dataset will be useful to researchers and practitioners working in the retinal imaging area and would widely encourage comparative studies in the field of diabetic retinopathy research. It is envisaged that the proposed decision support system for clinical screening would greatly contribute to and assist the management and the detection of diabetic retinopathy. It is also hoped that the developed automatic detection techniques will assist clinicians to diagnose diabetic retinopathy at an early stage

Biometric Systems

Biometric authentication has been widely used for access control and security systems over the past few years. The purpose of this book is to provide the readers with life cycle of different biometric authentication systems from their design and development to qualification and final application. The major systems discussed in this book include fingerprint identification, face recognition, iris segmentation and classification, signature verification and other miscellaneous systems which describe management policies of biometrics, reliability measures, pressure based typing and signature verification, bio-chemical systems and behavioral characteristics. In summary, this book provides the students and the researchers with different approaches to develop biometric authentication systems and at the same time includes state-of-the-art approaches in their design and development. The approaches have been thoroughly tested on standard databases and in real world applications

Efficient implementation of video processing algorithms on FPGA

The work contained in this portfolio thesis was carried out as part of an Engineering Doctorate (Eng.D) programme from the Institute for System Level Integration. The work was sponsored by Thales Optronics, and focuses on issues surrounding the implementation of video processing algorithms on field programmable gate arrays (FPGA). A description is given of FPGA technology and the currently dominant methods of designing and verifying firmware. The problems of translating a description of behaviour into one of structure are discussed, and some of the latest methodologies for tackling this problem are introduced. A number of algorithms are then looked at, including methods of contrast enhancement, deconvolution, and image fusion. Algorithms are characterised according to the nature of their execution flow, and this is used as justification for some of the design choices that are made. An efficient method of performing large two-dimensional convolutions is also described. The portfolio also contains a discussion of an FPGA implementation of a PID control algorithm, an overview of FPGA dynamic reconfigurability, and the development of a demonstration platform for rapid deployment of video processing algorithms in FPGA hardware