Figure 5

Example of anti-aliasing. A demonstration of the effect of anti-aliasing in Caryoscope. (a) Anti-aliased text displayed by Adobe Acrobat 6.0 on an Apple computer running Macintosh OS 10.3.3. Note that the text appears as if drawn by smooth black ink but, upon magnification, it becomes clear that this smoothness is a visual illusion created by careful manipulation of the color of each pixel. (b) The analogous situation in Caryoscope, where the scaled sizes of the feature loci are smaller than one pixel on the display device. In this example, we applied a form of anti-aliasing by prefiltering, where we computed the color of each pixel based on the area of red rectangles it contains. See [20]. (c) Actual displays from Caryoscope showing how the Minimum feature width setting highlights different aspects of the data. The three deletions d on chromosome 1 are clearly distinct at a setting of zero, but are lost in the midst of other artificially expanded features when the setting is increased. On the other hand, the two amplification "spikes" a on chromosomes 3 and 5 are invisible at a setting of zero, but become visible when the setting is increased.