TeX (compressed file tex.eps.gz, 12K bytes)[from Volumes B and D of Computers & Typesetting]
Meta (compressed file meta.eps.gz, 9K bytes)
Mathematical Analysis of Algorithms (compressed file maa.eps.gz, 11K bytes)[from the title slide to my IFIP 71 talk, paper P46 on my list of publications]
Digital typography (compressed file typo.eps.gz, 16K bytes)[provenance unknown, probably Mike Spivak; somebody gave a me a xerox copy of this image, circa 1980]
John 3:16 (compressed file john316.eps.gz, 75K bytes) (Also in Acrobat form)[see 3:16 Bible Texts Illuminated for further information about this image]
Mathematics (calligraphy received as a birthday present, 10 January 2002, jpeg version, 511K bytes)
Mathematics (calligraphy received as a birthday present, 10 January 2002, Postscript approximation, 73K bytes)
Matthew 3:16 (JPEG file matt316.jpeg, 555K bytes) received as a present, 12 June 2006
Al1 (JPEG file al.jpeg, 157K bytes)
Al2 (GIF file by Andreas Schlechte---avoids the postmark, 125K bytes)
Al3 (like Al2 but with shading not engraving, 128K bytes)[A postage stamp issued by the USSR in 1983 to commemorate the 1200th anniversary of Muhammad al-Khowarizmi, after whom algorithms are named. Scanned at 300dpi.]
Err-and-err-and-err-again (compressed file h-k.eps.gz, 218K bytes)[a Grook by Piet Hein, rendered on a piece of Welsh slate in the shape of a superellipse; used as frontispiece in the book Mathematical Writing]
typecases-filled-with-souvenirs (JPEG file, 422K bytes)
triangles with 36-45-90 angles (PDF file, 285K bytes)
source file to make the font (METAFONT file, 27K bytes)
example of how to use it for tiling patterns (plain TeX file, 2K bytes)
Merry Christmas wrapping paper from Jablan tiles (PDF file, 18K bytes)
photos of The Art of Computer Programming (taken by Héctor García-Molina, 15 March 2015, 7MB)
photos of all the books (taken by Héctor García-Molina, 15 March 2015, 27MB)
photos of all the translations (taken by Héctor García-Molina, 15 March 2015, 44MB)
Don Knuth circa 1995 (TIFF file closeup.tif, 27K bytes)
same at higher resolution (TIFF file don-hires.tif.gz, 1.3M bytes)
same with different compression (JPEG file don-hires.jpg, 453K bytes)
[commissioned by the Stanford Engineering School]. Also a picture with Christos Papadimitriou taken at the University of Macedonia (2 July 2003), and a picture with Peter Naur taken by Jill Knuth at our home (18 January 1975).
Here's a pencil sketch made by The Lutheran High School Association of Greater Milwaukee (my alma mater); also a bitmap image based on that sketch.
And a stipple-style headshot prepared by the Wall Street Journal magazine in April 2015.
I've also received a nice portrait sketched by Alexandra Drofina of Computerra in Moscow; here is a lo-resolution GIF file as well as a hi-resolution TIFF file. Note: These images are provided for any use, via the CC-BY license.
And here are two photos that Dasha Slobozhanina took while I was lecturing at Case Western Reserve University on 14 May 2010:
Moving to 2012, Rajan P. Parrikar snapped these closeups in June:
And here's one by Peter Badge: