NAME
pcompos - composite RADIANCE pictures.
SYNOPSIS
pcompos [ -h ][ -x xres ][ -y yres ][ -b r g b ][ -lh h ][ -la ] [ -t
min1 ][ +t max1 ][ -l lab ][ =SS ] pic1 x1 y1 ..
or
pcompos [ -a ncols ][ -s spacing ][ -o x0 y0 ][ options ] pic1 pic2 ..
DESCRIPTION
Pcompos arranges and composites RADIANCE pictures and sends the result
to the standard output. Each input picture must be accompanied by an
anchor point (unless the -a option is used, see below). This anchor
point is the usually position of the picture’s left lower corner in the
final output, but can be changed for individual pictures with an =SS
option, where S is one of ’-’, ’+’ or ’0’, indicating the minimum,
maximum or center of the image, respectively. (For example, =+- would
indicate the anchor is relative to the right lower corner, and =-0
would indicate the anchor is relative to the center of the left edge.)
Negative anchor coordinates result in the input being cropped at the
origin. By default, the size of the output picture will be just large
enough to encompass all the input files. By specifying a smaller
dimension using the -x and -y options, input files can be cropped at
the upper boundary. Specifying a larger dimension produces a border.
The -b option specifies a background color to appear wherever input
files do not cover. The default value is black (0 0 0). The -h option
may be used to reduce the information header size, which can grow
disproportionately after multiple runs of pcompos and/or pcomb(1).
If input files overlap, later pictures will overwrite earlier ones. By
default, input files are copied unconditionally within the output
boundaries. The -t option specifies a lower threshold intensity under
which input pixels will not be copied to the output. The +t option
specifies an upper threshold. These options are useful for cutting
around irregular boundaries in the input.
The -l option can be used to specify a label for a specific picture,
which will be given a height determined by the -lh option (default 24
pixels) and placed in the upper left corner of the picture. This label
is generated by the program psign(1). The -la option instructs pcompos
to label each picture automatically by its name. This is particularly
useful in conjunction with the -a option for producing a catalog of
images (see example below). The -l option may still be used to
override the default label for a picture.
The -a option can be used to automatically compute anchor points that
place successive pictures next to each other in ncols columns. The
ordering will place the first picture in the lower left corner, the
next just to the right of it, and so on for ncols pictures. Then, the
next row up repeats the pattern until all the input pictures have been
added to the output. If the pictures are of different size, pcompos
will end up leaving some background areas in the output picture. There
will also be an unfinished row at the top if the number of pictures is
not evenly divided by ncols. The -s N option will cause each image to
be separated by at least N pixels. The -o x0 y0 option specifies a
nonzero anchor point for the bottom left image.
The standard input can be specified with a hyphen (’-’). A command
that produces a RADIANCE picture can be given in place of a file by
preceeding it with an exclamation point (’!’).
EXAMPLE
To put a copyright label at the bottom of a picture:
psign Copyright 1987 | pcompos inp.hdr 0 0 +t .5 - 384 64 > out.hdr
To make a catalog of images separated by white 10-pixel borders:
pcompos -la -a 4 -s 10 -b 1 1 1 dog*.hdr > alldogs.hdr
NOTES
Since there is a limit to the number of open files and processes, large
collections of images must be created in stages. Even if the system
limit on open files is large, pcompos places an artificial limit of
1024 on the number of open files and/or processes.
AUTHOR
Greg Ward
SEE ALSO
getinfo(1), pcomb(1), pfilt(1), psign(1), rpict(1)