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Next: 4.3.2 Constant Interval Arithmetic Up: 4 Graphs Previous: 4.3 Optimization: Function Rendering

4.3.1 Optimization: Super-Pixel Rendering

The algorithm presented so far is woefully inefficient for pedestrian graphs. Consider rendering

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at a resolution of tex2html_wrap_inline38249 . Rendering tex2html_wrap_inline38251 with pixel-based testing would require more than one million interval evaluations of S. Efficiency may be improved considerably by using super-pixel testing: testing a group of pixels with a single interval evaluation of S.

Automated symbolic reasoning may deduce that

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so that column-based testing may be used. Rendering tex2html_wrap_inline38251 with column-based testing would require more than one thousand interval evaluations of S. Efficiency may be improved considerably by using super-column testing: testing a group of pixels with a single interval evaluation of S.

With either method, partial information presented during rendering may be of limited utility. Super-pixel, and super-column, testing may present informative intermediate renderings.


next up previous notation contents
Next: 4.3.2 Constant Interval Arithmetic Up: 4 Graphs Previous: 4.3 Optimization: Function Rendering
Jeff TupperMarch 1996