--- ray/doc/man/man1/pcomb.1	2004/01/01 19:31:45	1.5
+++ ray/doc/man/man1/pcomb.1	2023/12/06 17:56:57	1.14
@@ -1,10 +1,12 @@
-.\" RCSid "$Id: pcomb.1,v 1.5 2004/01/01 19:31:45 greg Exp $"
+.\" RCSid "$Id: pcomb.1,v 1.14 2023/12/06 17:56:57 greg Exp $"
 .TH PCOMB 1 8/31/96 RADIANCE
 .SH NAME
 pcomb - combine RADIANCE pictures
 .SH SYNOPSIS
 .B pcomb
 [
+.B -h
+][
 .B -w
 ][
 .B "\-x xres"
@@ -39,7 +41,12 @@ but an arbitrary mapping can be assigned with the
 .I \-e
 and
 .I \-f
-options.
+options, similar to
+.I rcalc(1).
+(The variable and function definitions in each
+.I \-f source
+file are read and compiled from the RADIANCE library
+where it is found.)\0
 Negative coefficients and functions are allowed, and
 .I pcomb
 will produce color values of zero where they would be negative.
@@ -68,7 +75,7 @@ For example,
 would return the red component of the pixel from picture 3
 that is left 2 and up 1 from the current position.
 Although x offsets may be as large as width of the picture,
-y offsets are limited to a small window (+/- 8 pixels) due to efficiency
+y offsets are limited to a small window (+/- 32 pixels) due to efficiency
 considerations.
 However, it is not usually necessary to worry about this problem --
 if the requested offset is not available, the next best pixel is
@@ -113,6 +120,9 @@ give the exposure values for picture
 and
 .I pa(n)
 gives the corresponding pixel aspect ratio.
+Exposure values will be set to 1.0 for inputs with the
+.I \-o
+option set.
 Finally, for pictures with stored view parameters,
 the functions
 .I "Ox(n), Oy(n)"
@@ -138,8 +148,17 @@ If the current pixel is outside the view region,
 will return a negative value, and
 .I S(n)
 will return zero.
+The first input picture with a view is assumed to correspond to the
+view of the output picture, which is written into the header.
 .PP
 The
+.I \-h
+option may be used to reduce the information header size, which
+can grow disproportionately after multiple runs of
+.I pcomb
+and/or
+.I pcompos(1).
+The
 .I \-w
 option can be used to suppress warning messages about invalid
 calculations.
@@ -189,24 +208,27 @@ by preceeding it with an exclamation point ('!').
 .SH EXAMPLES
 To produce a picture showing the difference between pic1 and pic2:
 .IP "" .2i
-pcomb -e 'ro=ri(1)-ri(2);go=gi(1)-gi(2);bo=bi(1)-bi(2)' pic1 pic2 > diff
+pcomb \-e 'ro=ri(1)\-ri(2);go=gi(1)\-gi(2);bo=bi(1)\-bi(2)' pic1 pic2 > diff
 .PP
 Or, more efficiently:
 .IP "" .2i
-pcomb pic1 -s -1 pic2 > diff
+pcomb pic1 \-s \-1 pic2 > diff
 .PP
 To precompute the gamma correction for a picture:
 .IP "" .2i
-pcomb -e 'ro=ri(1)^.4;go=gi(1)^.4;bo=bi(1)^.4' pic > pic.gam
+pcomb \-e 'ro=ri(1)^.4;go=gi(1)^.4;bo=bi(1)^.4' inp.hdr > gam.hdr
 .PP
 To perform some special filtering:
 .IP "" .2i
-pcomb -f myfilt.cal -x xmax/2 -y ymax/2 input.pic > filtered.pic
+pcomb \-f myfilt.cal \-x xmax/2 \-y ymax/2 input.hdr > filtered.hdr
 .PP
 To make a picture of a dot:
 .IP "" .2i
-pcomb -x 100 -y 100 -e 'ro=b;go=b;bo=b;b=if((x-50)^2+(y-50)^2-25^2,0,1)' > dot
+pcomb \-x 100 \-y 100 \-e 'ro=b;go=b;bo=b;b=if((x-50)^2+(y-50)^2\-25^2,0,1)' > dot
+.SH ENVIRONMENT
+RAYPATH		the directories to check for auxiliary files.
 .SH AUTHOR
 Greg Ward
 .SH "SEE ALSO"
-getinfo(1), icalc(1), pcompos(1), pfilt(1), rpict(1)
+getinfo(1), icalc(1), pcompos(1), pfilt(1), rcalc(1),
+rmtxcomb(1), rmtxop(1), rpict(1)