Creating a Tiling of Images
The Imagemagick package provides many utilities to display and manipulate
images. The montage program creates tilings of several images.
Montage can use several image formats. If your
images were produced on an SGI workstation and have the extension rgb, be sure
to read about SGI image formats. If
In the following examples, I used 6 images, m1.xwd, m2.xwd, m3.xwd, m4.xwd,
m5.xwd, and m6.xwd.
Here are several commands and the results.
- montage -tile 2x3 m1.xwd m2.xwd m3.xwd m4.xwd m5.xwd m6.xwd one.gif
The last file name is where the tiled image is stored.
Don't forget to name the output image. I have lost many files by
forgetting to to this.
montage -tile 2x3 m*.xwd one.gif would also work, assuming these
are the only files in the current directory that start with 'm' and end with
".xwd",
The option -tile 2x3 produces 3 rows, 2 images per row. Without
this option, you will get 5 tiles in each row and up to 4 rows.
- montage -tile 2x3 +label m1.xwd m2.xwd m3.xwd m4.xwd m5.xwd m6.xwd no-label.gif
A + in front of front of an option turns that option off.
- montage -tile 2x3 +label +frame m1.xwd m2.xwd m3.xwd m4.xwd m5.xwd m6.xwd no-frame.gif
Note: Both the label and the frame are off.
- montage -tile 2x3 -geometry 208x151! +label +frame m*.xwd larger.gif
The original images were 833 by 604 pixels. Each image was scaled to 208
by 151 pixels and then combined. An 8.5 x 11 postscripts page is 612x792
pixels (72 pixels per inch). When I scaled this image I divided each
dimension by 4 to preserve the aspect ratio. To determine the size of the
image m1.xwd, I typed identify m1.xwd The dimensions appear just
after the file name.
The ! after the size forces the dimensions of each image to be
exactly 208x151.
Without stating the geometry option, each image is scaled to 120x120
- montage -tile 2x3 +label -geometry 208x151! -borderwidth 1 -backgroundcolor black m*.xwd small-border.gif
Note: The program may crash if the background color is not specified and the
border width is small.
Image Formats
The Imagemagick routines handle an amazing number of image formats. The file
name extension names the image format. You may combine, using montage, many
files of different image formats into one file.
In the above examples, all 6 input files had the extension xwd, which
is the X window dump format. The output file had the extension gif,
which is Compuserve's graphics image format. Again, the formats of the input
files may all be different.
The following is from the man page for the convert program that is part
of Imagemagick and shows the image formats that montage can handle.
AVS AVS X image file.
BMP Microsoft Windows bitmap image file.
CMYK Raw cyan, magenta, yellow, and black bytes.
EPS Adobe Encapsulated PostScript file.
EPSF Adobe Encapsulated PostScript file.
EPSI Adobe Encapsulated PostScript Interchange format.
FAX Group 3.
FITS Flexible Image Transport System.
GIF Compuserve Graphics image file.
GIF87 Compuserve Graphics image file (version 87a).
GRAY Raw gray bytes.
HDF Hierarchical Data Format.
HISTOGRAM
JBIG Joint Bi-level Image experts Group file interchange format.
JPEG Joint Photographic Experts Group file interchange format.
MAP Red, green, and blue colormap bytes followed by the
MATTE Raw matte bytes.
MIFF Magick image file format.
MTV MTV Raytracing image format.
NULL NULL image.
PCD Photo CD.
PCX ZSoft IBM PC Paintbrush file.
PDF Portable Document Format.
PICT Apple Macintosh QuickDraw/PICT file.
PNG Portable Network Graphics.
PNM Portable bitmap.
PS Adobe PostScript file.
PS2 Adobe Level II PostScript file.
RAD Radiance image format.
RGB Raw red, green, and blue bytes.
RGBA Raw red, green, blue and matte bytes.
RLE Utah Run length encoded image file; read only.
SGI Irix RGB image file.
SUN SUN Rasterfile.
TEXT raw text file; read only.
TGA Truevision Targa image file.
TIFF Tagged Image File Format.
TILE tile image with a texture.
VICAR read only.
VID Visual Image Directory.
X select image from X server screen.
XC constant image of X server color. Specify the desired
color as the filename.
XBM X11 bitmap file.
XPM X11 pixmap file.
XWD X Window System window dump image file.
YUV CCIR 601 4:1:1 file.
YUV3 CCIR-601 4:1:1 files.
SGI Image Formats
Unfortunately, SGI and Imagemagick use the extension rgb to indicate different
formats. Whenever you use an rgb file produced by an SGI workstation in an
Imagemagick routine, you must proceed it by sgi:
For example, the command
montage -tile 2x3 sgi:m1.rgb sgi:m2.rgb sgi:m3 sgi:m4.rgb sgi:m6.rgb
sgi:m6.rgb image.jpg
Creates a tiling of 6 rgb images produced by an SGI workstation and outputs one
image in jpeg format.
To make it easier, you may want to rename your SGI produced files to have
the extension sgi. In this case, the above command could be
montage -tile 2x3 m*.sgi image.jpg
Further Assistance
For further assistance, contact Barry Schaudt (schaudt@msi.umn.edu).