From 3e3becba38aae40963fa71988a5b998351619752 Mon Sep 17 00:00:00 2001 From: giraffedata Date: Sat, 14 Nov 2020 19:53:03 +0000 Subject: miscellaneous update git-svn-id: http://svn.code.sf.net/p/netpbm/code/userguide@3987 9d0c8265-081b-0410-96cb-a4ca84ce46f8 --- pamarith.html | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/pamarith.html b/pamarith.html index 0f300048..7127bc89 100644 --- a/pamarith.html +++ b/pamarith.html @@ -39,11 +39,15 @@ output.

For functions that are commutative and associative, pamarith applies the binary function repetitively on as many input images as you supply. For - example, for -add , the output is the sum of all the inputs; for - -equal, it tells you whether all the inputs are equal. For other - functions (e.g. -subtract), the program fails if you supply more - than two input images. (Before Netpbm 10.51 (June 2010), the program always - failed with more than two input images). + example, for -add , the output is the sum of all the inputs. For + other functions (e.g. -subtract), the program fails if you supply + more than two input images. (Before Netpbm 10.93 (December 2020), the + program always failed with more than two input images). + +

For some other functions, pamarith could theoretically compute a + meaningful result for multiple arguments, but it fails nonetheless if you + give more than two input images. -mean and -equal are in that + category.

Most of what pamarith does is not meaningful for visual images. It works toward Netpbm's secondary purpose of just manipulating arbitrary @@ -322,7 +326,7 @@ that made it backward compatible with pnmarith.

The -divide option was added in Netpbm 10.30 (October 2005).

The ability to have more than one input (operand) was added in Netpbm -10.51 (June 2010), but not documented until October 2020. +10.93 (December 2020).

The -equal option was added in Netpbm 10.93 (December 2020). -- cgit 1.4.1