### Errata list for Manual of Computer Graphics

Last Updated 11 May 2018

Errors found by the author

Plate E.1. "Subviding" should be "Subdividing".

Plate G.3. "Dye" should be "Die".

Page 110. See error correction for page 1226.

Page 1226. The Bayer filter is named after its developer, Bryce E. Bayer (1929--2012). Bayer, a scientist at Eastman Kodak, received U.S. Patent No. 3,971,065 in 1976 for the filter.

It is interesting to note that he suggested in his patent application that either RGB or CMY colors could be employed in the filter.

Bayer was also the developer of the recursively-defined matrices used in ordered dithering (matrices D_22 and D_44 on page 110).

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Error found by Mahmoud El-Sakka

Pages 639-640. The CALIC encoder algorithm listed on these pages is wrong. This error has been in the book since the 2nd edition.
Anyone interested in CALIC is invited to submit a listing of the correct algorithm to the authors.

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Error found by Fred and Kay Skripka

Page 1495, line -25. "Scott H. L." should be "Scott, Herschal Lee (artist, 1945--2012)"

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Errors found by Zack Lindbloom-Brown

1) On page 336 of Volume 1, shouldn't the expressions read P_L = P \dot T_L and P_R = P \dot T_R? This would be consistent with P_{left} and P_{right} on page 333.

2) The example at the top of page 334 with P = (5, 0, 1), leads to P_{left} = (7/4, 0) and P_{right} = (3/4, 0). Intuitively, wouldn't one expect the x-component of P_{left} to be less than P_{right}'s,
since P resides to the right of the midline of the two eyes? As written, it seems that the left eye's image crosses over the right.

The following comment refers to the 1992 article:

L.F. Hodges, Tutorial: time-multiplexed stereoscopic computer graphics,
IEEE Computer Graphics and Applications (Volume: 12, Issue: 2, March 1992).

3) On page 24 of this article, the equations (2) and (3) are the same as your x_L and x_R in the middle of page 334, except for a sign flip in the numerator.
Both sources appear to use a left-handed coordinate system, and both state that the left and right eyes, respectively, are situated at (-e, 0, -k) and
(e, 0, -k) (minor details: they consider e to be the distance between eyes whereas you picked 2e, and d = k). Why the sign difference? (See next point.)

4) Middle of page 334: "The two eyes are located at (e, 0, -k) and (-e, 0, -k)," which according to Figure 6.58a,c, and d implies that the left eye is now at (+e, 0, -k),
whereas the last sentence of page 332 and Figure 6.55b clearly show the left eye at (-e, 0, -k). This flip from left-handed coordinates to right-handed likely explains
the sign difference seen in Point 3) above. To prevent confusion (I know I certainly was), you may consider using the same coordinate convention for both projections.

5) When deriving the sophisticated approach for generating a stereo image, in the middle of page 334, the mysterious w variable should really be e.

6) In the Code for Figure 6.56 on page 335, the matrix Trg is not used. The comment should read "(* use Trg for the other image *)"

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Once or twice he [Joyce] dictated a bit of Finnegans Wake to Beckett, though dictation did not work very well for him; in the middle of one such session there was a knock at the door which Beckett didn't hear. Joyce said,
"Come in," and Beckett wrote it down. Afterwards he read back what he had written and Joyce said, "What's that Come in'?" "Yes, you said that," said Beckett. Joyce thought for a moment, then said, "Let it stand."
He was quite willing to accept coincidence as his collaborator.

Richard Ellmann, James Joyce (1959).

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