Choosing a “good” set of colours for a graphical display is an important problem, but one which many data analysis practitioners are ill-equipped to solve. Most current graphics systems provide very little assistance in making good colour choices. Indeed, most systems require that a user specify their colours in ways which are closely related to the hardware representation of the colours rather...

4 Exploratory graphics 15 4.1 Univariate exploratory graphics . . . . . . . . . . . . . . . . . . 15 4.1.1 Enhancing the histogram* . . . . . . . . . . . . . . . . . 17 4.1.2 Kernel density* . . . . . . . . . . . . . . . . . . . . . . . 18 4.1.3 Another histogram enhancement: colour-coding relative frequency* . . . . . . . . . . . . . . . . . . . . . . . 20 4.2 Bivariate exploratory graphics . ...

In this paper~ the problem of 'hiddensurface' eli mination is considered. It is shown that a new linear surfacefilling algorithm leads to some simple techniques for hidden-surface removal . Necessary conditions are establ ished for three such me thods to vwrk and hard ware to implement these solutions is shown to be practicable . Each of the three proposed methods is seen to have actvantages in...

This paper describes sensors and algorithms developed and used for the creation of coloured 3-D triangular meshes from a set of range images with registered colour measurements. The objective is the creation of a digital model of a real object that is compatible with established computer graphics techniques. Triangular meshes are the fundamental rendering primitive supported by most high perfor...

Gradient meshes are a 2D vector graphics primitive where colour is interpolated between mesh vertices. The current implementations of gradient meshes are restricted to rectangular mesh topology. Our new interpolation method relaxes this restriction by supporting arbitrary manifold topology of the input gradient mesh. Our method is based on the Catmull-Clark subdivision scheme, which is well-kno...

Tiling projectors provides an effective and easy option to increase screen space. Differences in projectors' components however contribute to non-uniformities in illumination and colour and detract from image quality and useability. In collaboration with JVC we developed a compact, high-resolution, uniform, tiled projection computer display based on a single common light source. A single set of...

We present a Self-Organizing Kohonen Neural Network for quantizing colour graphics images. The network is compared with existing algorithmic methods for colour quantization. It is shown experimentally that, by adjusting a quality factor, the network can produce images of much greater quality with longer running times, or slightly better quality with shorter running times than the existing metho...

An object-oriented computational framework for the transformation of colour data and colour metric tensors is presented. The main idea of the design is to represent the transforms between spaces as compositions of objects from a class hierarchy providing the methods for both the transforms themselves and the corresponding Jacobian matrices. In this way, new colour spaces can be implemented on t...