pnmmontage

Updated: 22 November 2012
Table Of Contents

NAME

pnmmontage - create a montage of PNM images

SYNOPSIS

pnmmontage [-header=headerfile] [-quality=n] [-prefix=prefix] [-0|-1|-2|...|-9] [-data=filename] pnmfile...

DESCRIPTION

This program is part of Netpbm.

pnmmontage packs images of differing sizes into a minimum-area composite image.

Areas of the output that cannot be occupied by an image are black.

OPTIONS

-data=filename

This option causes pnmmontage to write a file that describes in machine-readable form the positions of the original images within the packed image. Here is an example:


            :0:0:227:298
            ../image1.ppm:0:0:227:149
            ../image2.ppm:0:149:227:149

There is a line for each component image and one for the composite.

The 5 fields on each line are:

source image name (or null string indicating the line for the composite image)
Column number of upper left corner of the image
Row number of upper left corner of the image
width of the image (columns)
height of the image (rows)

This option was new in Netpbm 10.6 (July 2002).

-header=filename

Tells pnmmontage to write a C header file of the locations of the original images within the packed image. Each original image generates four #defines within the packed file: xxxX, xxxY, xxxSZX, and xxxSZY, where xxx is the name of the file, converted to all uppercase. The output also includes #defines OVERALLX and OVERALLY, which specifies the total size of the montage image.

Here is an example:


            #define OVERALLX 227
            #define OVERALLY 298
            
            #define X 0
            #define Y 0
            #define SZX 227
            #define SZY 149
            
            #define X 0
            #define Y 149
            #define SZX 227
            #define SZY 149

-prefix

Tells pnmmontage to use the specified prefix on all of the #defines it generates.

-quality

Before attempting to place the subimages, pnmmontage will calculate a minimum possible area for the montage; this is either the total of the areas of all the subimages, or the width of the widest subimage times the height of the tallest subimage, whichever is greater. pnmmontage then initiates a problem-space search to find the best packing; if it finds a solution that is (at least) as good as the minimum area times the quality as a percent, it will break out of the search. Thus, -quality=100 will find the best possible solution; however, it may take a very long time to do so. The default is -quality=200.

-0, -1, ... -9

These options control the quality at a higher level than -quality; -0 is the worst quality (pick the first solution found), while -9 is the best quality (perform an exhaustive search of problem space for the absolute best packing). The higher the number, the slower the computation. The default is -5.

NOTES

Using -9 is very slow on all but the smallest image sets.

The minimum area arrangement is often not a convenient shape. For example, it might be a tall, thin column of images, when you'd rather have something more square. To force a minimum width or height, you can include a strut image - a black image that wide and one pixel high. Similarly, you can use a vertical strut to force a minimum height.

HISTORY

pnmmontage was new in Netpbm 9.10 (January 2001).