Ubuntu Manpage: pcompos - composite RADIANCE pictures.

Provided by: radiance_4R1+20120125-1.1_amd64

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