This directory contains Release 1.2 of the Fuzzy Pixmap Manipulation
(FBM) library of programs. This collection provides a complete package
for manipulating and converting color and black and whites images,
including 24bit RGB, 8bit mapped color, 8bit grayscale, and 1bit
bitmapped images.
Compilation
Unpack all files in one directory. Edit Makefile and put in
appropriate values for defaults.
If you wish to have the tiff2fbm and fbm2tiff programs, first
obtain, unpack, and compile libtiff.a, and then modify FBM 's
Makefile to include this library. Then type "make tiff". Note
that some versions of libtiff are not careful to put file
tiffcompat.h into the intstall directory. The tifflib is
available from UCBVAX.BERKELEY.EDU, file pub/tiff/v3.0.tar.Z.
If you have the Utah Raster Toolkit, the 'fbcat' program can be
compiled with the -DRLE flag to include support for RLE files.
Credit for RLE support to Paul Milazzo <milazzo@pearl.bbn.com>.
Get the Toolkit from CS.UTAH.EDU, file pub/toolkit-2.0.tar.Z.
Get Jef Poskanzer's PBMPLUS source from EXPO.LCS.MIT.EDU, file
contrib/pbmplus.tar.Z.
File Formats
FBM (-F) FBM file with 256 byte header (with title & credits)
Sun (-S) Sun rasterfile with 32 byte header
Tiff (-T) Aldus TIFF
PBM (-P) Poskanzer format for 1bit files
GIF (-G) CompuServe GIF format
JPG (-J) JPEG JFIF format (cf The Independent JPEG Group)
RLE (-R) Utah RLE format
IFF (-I) Amiga IFF files (except HAM mode files)
PCX (-Z) PC PaintBrush format for IBM
Face (-B) Bennet Yee's 1bit files, used at CMU
All programs (except fbinfo) can read any of the formats, and use
the magic number to decide the file type. If the input is not a
pipe and is compressed using the net standard 'compress' program,
the file will be uncompressed as it is read. Note however that
the operation to be performed must make sense; that is you cannot
halftone a color image, quantize a grayscale image, or resize a
1bit file.
Files and Programs:
README This file
README.lib Lists the subroutines in libfbm.a
Makefile Make utility configuration file
fbm.1 General manual entry
*.1 Individual manual entries
fbm.h Defines FBM data structures
clr2gray Convert color to grayscale
fbcat Copy image (used for format conversion)
fbclean Flip isolated pixels (clean image)
fbconv Arbitrary convolutions
fbedge Compute derivative image (edge detection)
fbext Extract region, resize, change aspect ratio
fbgamma Gamma correct grayscale or color image for display
fbhalf Halftone grayscale image (Blue noise, Floyd-Steinberg, etc)
fbham Convert FBM 24bit RGB to Amiga HAM mode
fbhist Compute histogram
fbinfo Dump image header
fbm2pod Convert grayscale image to Diablo graphics (!)
fbm2tga Convert image to Targa format
fbm2tiff Convert FBM files to 1, 2, 4, 8, or 24 bit TIFF
fbmask Set region to gray value
fbmedian Median filter 3x3 regios
fbnorm Normalize image intensity / increase contrast
fbpalet Replace an imager's colormap with another, remove duplicates
fbps Convert to PostScript
fbquant Color quantization (24 bit to 8..256 colors) Mod. Heckbert
fbrot Rotate 90, 180, or 270 degrees
fbthin Thin 1bit images
fbsample Sample a 1bit file to produce an 8bit file
fbsharp Sharpen (edge enhancement) by digital Laplacian
gray2clr Add a "gray" colormap to a grayscale image
idiff (and udiff) convert raw byte stream into byte difference
pbm2ps Convert PBM file to PostScript
pbmtitle Add a title to a PBM file
raw2fbm Convert raw file to FBM format (eg: Amiga Digiview files)
tga2fbm Convert Targa file to FBM format
tiff2fbm Convert tiff file to FBM format
uunet2fbm Convert UseNet Facesaver file to FBM format
Extensions
Several file extension conventions are used, but none are enforced
.Z Compressed file, appended to other extensions
.fbm Standard extension for FBM format files
.cbm Sometimes used to mean a 24bit color FBM file
.ip 8bit grayscale Amiga file (with 1.2 aspect ratio)
.cp 24bit color Amiga file (with 1.2 aspect ratio)
.1bit Sun 1bit rastefile
.clr Sometimes used to mean a 8bit mapped color Sun file
.bm Bennet Yee's "Face" format (1bit)
.pbm Poskanzer 1bit format
.gif Compuserve GIF format
.jpg or .jpeg JPEG JFIF format
.pcx ZSoft's PCPaintbrush format
.tif or .tiff Aldus's TIFF format (used on NeXT)
Example Unix pipelines to view files:
Starting with an 8 bit raw Amiga grayscale file, foo.ip, first
create an FBM format file with a title and credit, then process
that file for viewing on a Sun screen by normalizing, rotating,
resizing, sharpening, and halftoning.
% raw2fbm -d1 -a1.2 -w640 -h400 \
-t'Random Title' -c'Random Credit' < foo.ip > foo.fbm
% fbinfo foo.fbm
foo.fbm "Random Title"
[ Random Credit ]
[640x400x8] 8 physbits 1.2 aspect ratio
row length 640, plane length 256000, colormap length 0
% fbnorm < foo.fbm | \ (normalize)
fbrot | \ (rotate 90 deg clockwise)
fbext -a1 -W900 -H768 | \ (resize & make aspect ratio 1)
fbhalf -s10 -S > foo.1bit (sharpen, halftone, write Sun)
Starting with a 24 bit color Amiga file, bar.cp, first create an
FBM format file with title and credit, then render that file for
viewing on a Sun by normalizing, rotating, sharpening, and
quantizing.
% raw2fbm -d3 -a1.2 -w640 -h400 \
-t'Random Color Title' -c'Random Color Credit' < bar.cp > bar.cbm
% fbinfo bar.cbm
bar.cbm "Random Color Title"
[ Random Color Credit ]
[3x640x400x8] 8 physbits 1.2 aspect ratio
row length 640, plane length 256000, colormap length 0
% fbnorm < bar.cbm | \ (normalize)
fbrot | \ (rotate 90 deg clockwise)
fbext -a1 -W900 -H768 | \ (resize & make aspect ratio 1)
fbsharp 3.0 | \ (sharpen it)
fbquant -S > bar.clr (quantize and write Sun)
(Note that sharpening is an integral option to the halftoning
program using the -s option, but that color images must currently
be sharpened using a separate program. Note also that more
sharpening is used on black and white images than on color images).
Starting with a 256 color Sun raster image, baz.clr, generate a NeXT
readable 2bit grayscale image (note fbm2tiff is not a filter, but
writes to a named file. Tiff2fbm reads a named file):
-- Without Dithering --
% clr2gray < baz.clr | \ (convert to gray)
fbm2tiff -N baz.tiff (chop 8bit grays to 2bit)
-- With Dithering (note 1) --
% clr2gray < baz.clr | \ (convert to gray)
fbnorm | \ (normalize, optional)
unmap | \ (convert to RGB)
fbquant -c4 | \ (fbquant also dithers RGB)
clr2gray | \ (back to gray: 0, 85, 190, 255)
fbm2tiff -N baz.tiff (convert 4 grays to NeXT 2bit)
Note 1: Yes, this is gross...and inefficient. But the
images look fine. Dithering should be an option of fbm2tiff,
and really the halftoning algorithms should be generalized
to produce more than just bitmaps.
Notes on the 'fbext' program
Usage: fbext [ -w<width> -h<height> -W<maxwdith> -H<maxheight>
-s<size> -a<aspect> -t'title' -c'credits' ]
[ x y [ width height ] ]
< foo.fbm > bar.fbm
fbext (bitmap extract) is a very useful anmd multipurpose program.
Its basic operation is to copy a rectangular portion of one image
(color or black and white) to a second image, possibly changing
either the width or height or both. It can also change the title
or credits fields of the image. Because it is so versatile, there
are a host of options:
-w<num> or -h<num> Force width and/or height to a certain size
-W<num> or -H<num> Limit width and height to a certain size
-a<num> Force the output to have a given aspect ratio
-s<num> Scale image to have no more than a given
number of pixels.
<x0> <y0> <width> <height> select a rectangular region of the image
to extract. The default is the entire image.
Note that the output size limits are cumulative. Thus if you set a
maximum width, height, and number of pixels, the image will be the
smallest of the three limits.
Notes on JPEG support
All routines support JPEG output, but not all routines actually
produce the 8 bit grayscale or 24 bit RGB color suitable for
writing to JPEG format. In those cases, the JPEG routines will
complain.
Only the fbcat(1) program supports the -q<quality> switch
which allows you to specify a JPEG quality other than the
default of 75.
