The Libnetpbm Netpbm Image -Processing Manual describes the the libnetpbm functions for +Processing Manual describes the libnetpbm functions for processing image data.
The Libnetpbm Utility Manual diff -u -r --new-file old/userguide/pamfunc.html new/userguide/pamfunc.html --- old/userguide/pamfunc.html 2020-07-22 13:59:14.000000000 -0500 +++ new/userguide/pamfunc.html 2020-07-22 14:25:33.630737946 -0500 @@ -55,7 +55,7 @@ and bit string (such as and with 01001000). For the arithmetic functions, the function arguments and results are the fraction that a sample is of the maxval, i.e. normal interpretation of PAM tuples. But for the bit string -functions, the value is the the bit string whose value as a binary cipher is +functions, the value is the bit string whose value as a binary cipher is the sample value, and the maxval indicates the width of the bit string.
Before Netpbm 10.79 (June 2017), there was a different program by the same -name in Netpbm, which was written by by Paul Haeberli +name in Netpbm, which was written by Paul Haeberli <paul@manray.sgi.com> in 1989 and then modified extensively by others.