Automatic Colour Transfer Function Generation and 3D Reconstruction of DICOM Images

-This paper describes initial results of a 3D field topology analysis for automating colour transfer function design aiming at comprehensible volume rendering. Computed tomography (CT) scanners measure the linear xray radio density attenuation values of body tissues in Hounsfield units (HU). Many alternative colour maps have little additional diagnostic or intuitive value relative to grayscale. Colour realism is essential to surgeons’ perceptions as they predominantly examine tissue either with the naked eye or through a camera .When looking at a grayscale CT image, one has to look at the shade of the object relative to other known structures in order to identify it rather than its inherent hue. Structures with no inherent shape, location, or texture are particularly challenging. For example, free fluid in the peritoneal cavity may be bloody, purulent, or serous, each of which have different densities but all appear as a medium gray in a typical abdominal window. Radiologists often explicitly measure the density of peritoneal fluid in Hounsfield units via an image query tool since the shape, location and texture are not sufficiently informative and there is no colour information in grayscale. The Automatic Colour Transfer Function has been applied to an interactive, 3D, volume rendered of colourmapped data. The algorithm can be incorporated into other twoand three-dimensional visualization software or environments where colour tables are used to represent information, as well as environments that render 2D and 3D representations of higher dimensional datasets, including in other domains.