FBM (Fuzzy Bitmap Manipulation) This directory contains Release 1.0 of the Fuzzy Pixmap Manipulation (FBM) library of programs. This collection (in combination with Jef Poskanzer's PBM 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/v2.2.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 . 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 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) 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 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 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 .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 generalizes to produce more than just bitmaps. Notes on the 'fbext' program Usage: fbext [ -w -h -W -H -s -a -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 or -h Force width and/or height to a certain size -W or -H Limit width and height to a certain size -a Force the output to have a given aspect ratio -s Scale image to have no more than a given number of pixels. 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.