Frédéric Labrosse and Philip Willis.
Towards Continuous Image Representations.
In Proceedings of the International Conference in Central
Europe on Computer Graphics, Visualization and Computer
Vision (WSCG), pages 206-213, Plzen, Czech Republic, 2001.
We propose in this paper a first step towards the creation of
continuous, i.e. vectorial, representations that are
useful for image manipulation. Such pixel-free representations
have many advantages and are amenable to operations which are
difficult or imprecise with pixels. For example, they can
readily be rendered at different resolutions and they are a
better choice for ultra-high resolution applications. We explore
an approach in which images are decomposed into structural
regions that correspond to specified image characteristics. This
is done using relaxation labelling. Information taken at
different stages during the relaxation is used to extract
sub-pixel accurate continuous structural contours. This
accuracy is obtained by using snakes as well as the blur present
in images (because of the acquisition process). We propose
solutions, adapted to our context, to often mentioned problems of
snakes, namely initialisation, parameter determination, and
instability. The interior of structural regions is represented
to allow the rendering of images as close as possible to the
original ones. We propose here two schemes, one using a single
colour for each region, the second sampling the original image to
allow smoothly varying colour in each region.