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Issue No.06 - June (1986 vol.6)
pp: 36-42
David Salesin , California Insitute of Technology
Ronen Barzel , California Insitute of Technology
Ordinary bitmaps allow pixels to be black or white. We introduce a second bitmap, the "alpha" bitmap, which allows pixels to be transparent as well. The alpha bitmap makes it possible to have black-and-white images that are nonrectangular or that have holes in them. It also provides a richer set of operations for working with bitmaps. We present the mathematics for a two-bit compositing algebra, and suggest extensions for two-bit compositing, painting, and region filling. Each of these operations can be implemented with ordinary bitblts and presented on ordinary bitmap displays. We analyze the cost of each two-bit operation in terms of the number of bitblts it requires.
David Salesin, Ronen Barzel, "Two-Bit Graphics", IEEE Computer Graphics and Applications, vol.6, no. 6, pp. 36-42, June 1986, doi:10.1109/MCG.1986.276740
1. RobPike, LeoGuibas, and DanIngalls, "Bitmap Graphics," Computer Graphics (Proc. SIGGRAPH 84) July 1984 Vol. 18, No. 3, pp. 135-160
2. W.M.Newman and R.F.Sproull, Principles of Interactive Computer Graphics , McGraw-Hill 1979pp. 263-277
3. C.P.Thacker, "Alto—A personal computer," , Xerox PARC Aug. 1979
4. "Lisp Machine Manual," 1981 D. Weinreb and D. Moon MIT
5. ThomasPorter and TomDuff, "Compositing Digital Images," Computer Graphics (Proc. SIGGRAPH 84) July 1984 Vol. 18, No. 3, pp. 253-259
6. RobPike, ACM Transactions on Graphics , 1984pp. 135-160
7. Leo J.Guibas and JorgeStolfi, ACM Transactions on Graphics , 1982pp. 191-214
8. JohnWarnock and Douglas K.Wyatt, "A Device Independent Graphics Imaging Model for Use With Raster Devices," Computer Graphics (Proc. SIGGRAPH 82) July 1982 Vol. 16, No. 3, pp. 313-319
9. LarryTesler, Byte , Aug. 1981pp. 90-147
10. David CanfieldSmith, CharlesIrby, RalphKimball, BillVerplank, and ErikHarslem, Byte , Apr. 1982pp. 242-282
11. GreggWilliams, Byte , Feb. 1983pp. 33-50
12. LeoGuibas, Personal communication , 1986
13. James D.Foley and Andriesvan Dam, Fundamentals of Interactive Computer Graphics , Addison-Wesley 1982pp. 684
14. AdamLevinthal and ThomasPorter, "Chap—A SIMD Graphics Processor," Computer Graphics (Proc. SIGGRAPH 84) July 1984 Vol. 16, No. 3, pp. 77-82
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