Ophthalmic and neurological complications are frequent findings in patients with AIDS. Little is known about neuroretinal dysfunction in patients with HIV infection. The purpose of this study was to measure and evaluate colour vision in patients with HIV infection or AIDS. Colour contrast sensitivity tests were performed on 75 patients (150 eyes) in different stages of HIV infection. A highly s...

To faithfully represent a scene through non-photorealistic rendering (NPR), it is vital that all available scene data be taken into account. We present an automatic hybrid framework for creating abstractions of 3D scenes in real-time. Our approach uses a combination of object-space and image-space information to produce stylistic and reliable results. Calculations using scene vertex data are co...

The developments within the MEDIAMAPS project were motivated by the idea to provide small and medium companies with a solution to benefit from Web Business Geographic Applications (WBGA) advantages at an affordable price : a Webmapping application service with which the user only pays for used data and analysis processes. As one of the goals of this research was to give users the possibility to...

Digital image representation is perceptually uniform if a small perturbation of a component value – such as the digital code value used to represent red, green, blue, or luminance – produces a change in light output at a display that is approximately equally perceptible across the range of that value. Most digital image coding systems – including sRGB (used in desktop graphics), BT.709 (used in...

Colour realism plays an important role in computer graphics and visualization. In this paper, we present a new approach to direct volume rendering based on the Kubelka-Munk theory of diffuse reflectance. We show that not only the Kubelka-Munk theory facilitates a correct spectral volume rendering integral suitable for both solid objects and amorphous matters in volume datasets, but also provide...

In the Land Mondrian retinex experiment (Land, 1974) a multicoloured abstract scene consisting of rectangular patches is illuminated using three projectors. Each projector is fitted with a coloured filter which passes either predominantly longwave, medium-wave or short-wave light. The intensity of light from each projector may be independently varied. Constructing a computerised version of this...

This work presents the development of a graphics ontology for natural language interfaces. In a first phase, the ontology was developed in a standard way, based on documentations and textbooks for graphics systems as well as existing ontologies. In the second phase, we collected sets of natural language instructions to create and modify graphic images from human subjects. In these sentences, pe...

The processing and analysis of colour images has become an important area of study and application. The representation of the RGB colour space in 3D-polar coordinates (hue, saturation and brightness) can sometimes simplify this task by revealing characteristics not visible in the rectangular coordinate representation. The literature describes many such spaces (HLS, HSV, etc.), but many of them,...

The purpose of this article was to assess the suitability of softproofs as a surrogate for the final print in judging colourreproduction quality. A complex viewing apparatus was specially designed for this study to ensure that no cognitive cues were visible to observers and that the surround conditions for viewing softcopies and hardcopies were in very close agreement. Two experiments targeting...