Assessment of paint appearance quality in the automotive industry

This thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University.In the modem automotive industry, more and more manufacturers recognise that vehicle paint appearance makes an important contribution to customer satisfaction. Attractive appearance has become one of the important factors for customers in making a decision to purchase a car. Objective measurement of the quality of autobody paint appearance, as perceived by the customer, in a repeatable, reproducible, continuous scale manner is an important requirement for improving the paint appearance. It can provide car manufacturers a standard reference to evaluate the quality of the paint appearance. This thesis mainly deals with the measurement of paint appearance quality in the automotive industry by investigating, identifying and developing measurement methods in this area. First of all, the 'state of the art' in the area of paint appearance measurement was presented, which summarised the concept of appearance, models, attributes and definitions. To further identify the parameters and instruments used in the automotive industry, a round robin test was launched to perform visual assessment and instrument measurements on a set of panels in some European car manufacturers. A summary of the correlation found between measurable parameters and visual assessment provided the basis of the further work. Based on the literature survey and round robin test results, the next work is mainly concentrated on the two most important parameters, 'orange peel' and 'metal texture effect', how to separate and evaluate them. Digital signal processing technique, FFT and Filtering, have been employed to separate them and a set of measures have been provided for evaluation. At the same time, the technique for texture pattern recognition was introduced to evaluate the texture effect when a fine texture comparison was needed. A set of computable textural parameters based on grey-tone spatial-dependence matrices gives good correlation directly corresponding to visual perception. To resolve the overall appearance modelling problem, two novel and more powerful modelling tools, artificial neural networks and fuzzy logic, are introduced to model the overall appearance. The test results showed that both of them are able to reflect the correlation between overall appearance and the major parameters measured from a painted surface. Finally, an integrated measurement system, 'Smart Appearance', was developed using the image processing techniques and the artificial neural network model. The implement results show that this system can measure the major attributes of paint appearance and provide an overall appearance index corresponding to human visual perception. This system is helpful to product quality control on car body paint. It also could be used on the paint production line for dynamic measurement.European Union BRITE EURAM Projec

Classification of ordered texture images using regression modelling and granulometric features

Structural information available from the granulometry of an image has been used widely in image texture analysis and classification. In this paper we present a method for classifying texture images which follow an intrinsic ordering of textures, using polynomial regression to express granulometric moments as a function of class label. Separate models are built for each individual moment and combined for back-prediction of the class label of a new image. The methodology was developed on synthetic images of evolving textures and tested using real images of 8 different grades of cut-tear-curl black tea leaves. For comparison, grey level co-occurrence (GLCM) based features were also computed, and both feature types were used in a range of classifiers including the regression approach. Experimental results demonstrate the superiority of the granulometric moments over GLCM-based features for classifying these tea images

Design of VR app applied to cognitive training

L’objectiu principal d’aquest projecte és el disseny d’una aplicació de realitat virtual per millorar el tractament dels pacients amb deteriorament cognitiu lleu, així com estudiar els possibles avantatges que aquesta tecnologia pot proporcionar en aquest camp. Es va escollir la realitat virtual perquè permet augmentar la sensació d’immersió pel que fa a les tecnologies actuals. Actualment la realitat virtual s’està utilitzant amb aquest tipus de tractament i està aconseguint gran resultats amb els pacients. A més, mitjançant l’ús d’aquesta tècnica d’immersió visual, s’espera que ajudi a millorar la capacitat dels pacients davant nous problemes, com pot ser la iniciació a la realitat virtual, una qüestió fonamental que ajuda a la millora dels pacients que es troben en les primeres etapes de la malaltia. L’aplicació consisteix en un entorn de supermercat virtual on el pacient pot realitzar diverses proves. En aquesta hi haurà diferents nivells amb diverses complexitats, sempre després d’haver realitzat un tutorial previ. L’aplicació s’ha realitzat en dues fases diferents: primer es va crear el guió, amb col·laboració amb la unitat d’Alzheimer de l’Hospital Clínic. Els nivells de l’aplicació es van definir aquí. El següent va ser la realització de l’aplicació amb col·laboració amb la companyia Vysion 360. Per a la seva utilització per la unitat d’Alzheimer de l’Hospital Clínic, l’aplicació tenia que complir diferents criteris. En primer lloc, els nivells de dificultat tenen que ser suficients per realitzar un tractament a llarg termini. En segon lloc, per crear una bona experiència de immersió, l’entorn creat té que ser el més realista possible. Finalment, s’ha creat una base de dades local per guardar la informació de totes les sessions, utilitzat posteriorment en l’anàlisi de evolució dels pacients. Amb aquesta aplicació, s’espera que els resultats en els pacients amb deteriorament cognitiu lleu milloren respecte a les tècniques anteriors. Especialment gràcies a la gran experiència d’immersió aconseguida amb la realitat virtual, la qual ajuda a la concentració dels pacients durant el tractament

PRISMS: remote high resolution in situ multispectral imaging of wall paintings

The non-invasive monitoring and examination of wall paintings in grotto sites, tombs and buildings is particularly important since these paintings are often extremely vulnerable. Traditionally, inspection of wall paintings at high resolution (i.e. sub-millimetre resolution) requires either scaffolding or some heavy and cumbersome mechanical structure to lift a person or camera to the upper parts of a wall or ceiling. We have developed a proto-type portable remote imaging multi-spectral camera that operates at ground level for in situ high-resolution colour and spectral imaging of wall paintings. We present here the latest developments for the instrument and examples of how the instrument can be used for diagnosis of wall paintings

Remote spectral imaging with simultaneous extraction of 3D topography for historical wall paintings

PRISMS (Portable Remote Imaging System for Multispectral Scanning) is designed for in situ, simultaneous high resolution spectral and 3D topographic imaging of wall paintings and other large surfaces. In particular, it can image at transverse resolutions of tens of microns remotely from distances of tens of metres, making high resolution imaging possible from a fixed position on the ground for areas at heights that is difficult to access. The spectral imaging system is fully automated giving 3D topographic mapping at millimetre accuracy as a by-product of the image focusing process. PRISMS is the first imaging device capable of both 3D mapping and spectral imaging simultaneously without additional distance measuring devices. Examples from applications of PRISMS to wall paintings at a UNESCO site in the Gobi desert are presented to demonstrate the potential of the instrument for large scale 3D spectral imaging, revealing faded writing and material identification

A curriculum guide for art in the elementary grades

Thesis (Ed.M.)--Boston Universit

Volumetric cloud generation using a Chinese brush calligraphy style

Includes bibliographical references.Clouds are an important feature of any real or simulated environment in which the sky is visible. Their amorphous, ever-changing and illuminated features make the sky vivid and beautiful. However, these features increase both the complexity of real time rendering and modelling. It is difficult to design and build volumetric clouds in an easy and intuitive way, particularly if the interface is intended for artists rather than programmers. We propose a novel modelling system motivated by an ancient painting style, Chinese Landscape Painting, to address this problem. With the use of only one brush and one colour, an artist can paint a vivid and detailed landscape efficiently. In this research, we develop three emulations of a Chinese brush: a skeleton-based brush, a 2D texture footprint and a dynamic 3D footprint, all driven by the motion and pressure of a stylus pen. We propose a hybrid mapping to generate both the body and surface of volumetric clouds from the brush footprints. Our interface integrates these components along with 3D canvas control and GPU-based volumetric rendering into an interactive cloud modelling system. Our cloud modelling system is able to create various types of clouds occurring in nature. User tests indicate that our brush calligraphy approach is preferred to conventional volumetric cloud modelling and that it produces convincing 3D cloud formations in an intuitive and interactive fashion. While traditional modelling systems focus on surface generation of 3D objects, our brush calligraphy technique constructs the interior structure. This forms the basis of a new modelling style for objects with amorphous shape

Designing identity of a new material: a new product design approach

The present research is a design practice-based research based on the industrial development of a new concrete. The research focuses on the development of the specific identity of a new material. The research is aimed at demonstrating that product design can be used as a new strategy to create the material identity and thus to differentiate from existing materials. In order to design material specific identity in new products, we need to understand the perception process of shaped materials. Therefore we conducted exploratory study of materials recognition in products. We identified two types of products: the “messenger” products are specific shapes characteristic from the material; the “wrong messenger” products are imitations of other well known materials. The results of questionnaire about material recognition show that it’s more or less easy to identify material according to each product (whether it’s familiar or new shapes; whether it’s imitation or specific shapes and whether it’s well known or new material). We conclude on two types of shapes: on the one hand some familiar and typical shapes make easier and more certain the material recognition; on the other hand some new shapes make people more uncertain of what it is made of but more amazed. Designing amazing new shapes can be used as a new differentiation strategy to create the specific sensory identity of each new material. It means that the product can be a really useful support to fully communicate about a new material, beyond the traditional material samples. Keywords: New Material; Sensory Identity; Product Design</p

Fast Simulation of Skin Sliding

Skin sliding is the phenomenon of the skin moving over underlying layers of fat, muscle and bone. Due to the complex interconnections between these separate layers and their differing elasticity properties, it is difficult to model and expensive to compute. We present a novel method to simulate this phenomenon at real--time by remeshing the surface based on a parameter space resampling. In order to evaluate the surface parametrization, we borrow a technique from structural engineering known as the force density method which solves for an energy minimizing form with a sparse linear system. Our method creates a realistic approximation of skin sliding in real--time, reducing texture distortions in the region of the deformation. In addition it is flexible, simple to use, and can be incorporated into any animation pipeline