This application is a filter service built upon the Portable BitMap toolkit by Jeff Poskanzer. Basically is uses the PBM+ tools to convert a large number of image formats into PBM formats and then uses pnmtotiff to convert the PBM format into a TIFF. The NXImage class will automatically invoke these filters to convert files and this gives you the ability to transparently open a large number of image files.
The PBMImageFilter determines the format of image file by the extension on the file name. The supported formats are:
Sun icon file .icon
X10 and X11 bitmap file .xbm
MacPaint .macp
CMU window manager format .cmuwm
MGR format .mgr
Group 3 FAX .g3
GEM .img format .gem
Bennet Yee's "face" format .ybm
Atari Degas .pi3 format .pi3
Andrew Toolkit raster object .atk
Xerox doodle brushes .brush
Usenix FaceSaver(tm) file .fs
FITS .fits
Lisp Machine bit-array-file .lispm
HIPS .hips
GIF .gif
IFF ILBM .iff
PICT .pict
Atari Degas .pi1 format .pi1
XPM (X Window System ASCII pixmaps) .xpm
PC Paintbrush .pcx format .pcx
TrueVision Targa file .tga
HP PaintJet format .pj
Abekas YUV format .yuv
MTV/PRT ray-tracer output .mtv
QRT ray-tracer output .qrt
Img-whatnot file .img
Xim file .xim
Atari uncompressed Spectrum .spct
Atari compressed Spectrum .sput
AutoCAD slide format .sld
Sun raster file .rast
X10/X11 window dump file .xwd
Portable Bitmap Files .pbm
Portable Greymap Files .pgm
Portable Pixmap Files .ppm
JPEG File Interchange Format .jpg
The PBM package has many other conversion utilities. If you want to convert from TIFF into a different format you can run tifftopnm and then one of the converters into the format you want.
Quick Installation:
Install the package pbmtools.pkg into /usr/local/bin. Install the package PBMImageFilter into /LocalLibrary/Services. Type make_services at a shell. At this point the program should run. Try to use Preview to open an image file that is in a format listed above.
Configuration:
There is a configuration file that PBMImageFilter uses. It is called config and is stored in the directory with the Filter. The first line of the file is used to set the general configuration information. First it has the number of image types the config file contains, then it has the directory containing the PBM tools, finally it has the name of the TIFF converter. Each of these is separated by whitespace. The following lines of the file list the extension for a particular type of image and the name of the converter for that type of image. The application starts by knowing about 37 different image types, where the PBM tools live in /usr/local/bin, and uses pnmtotiff as the converter to get to tiff format. There is one "hack" to be aware of. My filter expects to be two stages, one to get into PBM format and one to convert PBM format to TIFF. If you start with a PBM format you don't need the first stage. So, I just use the application "cat" as the first stage. Since cat isn't in the PBM bin directory it is hard coded to mean /bin/cat. This shouldn't cause any harm, but don't try to make a PBM converter that's called 'cat'.
The Filter will look for the PBM tool called pnmtotiff in the workspaces path first, then the default directory that you specified. The individual user may add a dwrite
PBMImageFilter PathToPBM <path>
to override this search path. Once it finds this program it assumes that all PBM converters are located in this directory.
Building and Installing:
The Makefile understands two targets all and install. Make all will build the PBMImageFilter and Make install will install it in ~/Library/Services. If you would like to install the service more globally, the change the line:
and the filters will be available to anyone on the machine.
Adding PBM Tools:
Adding tools is very easy.
1) Place an application in your PBM directory that converts the new image type into one of the PBM types.
2) Add one to the integer at the top of the config file.
3) Add your image extension and converter to the end of the config file.
4) Add a line to the services file that says:
Send Type: NXFilenamePboardType:<your extension>
Notice that you can not have more than 16 Send Types in a single service entry.
You will need to create a new service entry (to add more)
5) If PBMImageFilter is already running you will need to kill it.
Distribution:
There are three distributions to this package.
1) PBMImageFilter.binaries.tar.Z. This includes one installer package to install the PBMImageFilter and one to install the PBM binaries. This is about 4 megs.
2) PBMImageFilter.sources.tar.Z. This includes just the source to the PBMImageFilter and not the PBM package. This is about 22k.
3) PBM.sources.tar.Z. This includes the sources to the PBM package. This is about 4 megs.
Usage and Licensing:
Source code I have wrriten is
Copyright (C) 1993 by Daryll Strauss
other software, such as the PBM package is copyright by its author, but has
licensing similar to the following which is used in my source code.
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation. This software is provided "as is" without express or
implied warranty.
Donations/TradeWare?
If you think this program is useful and you or your company has a piece of shareware or comercial software available, I'd appreciate it if you'd send me a copy. You are welcome to use this software as licensed above regaurdless of whether or not you donate any software.
Contacting Me?
If you have any questions or comments about this software, I'll do my best to answer them. Send me mail at daryll@harlot.rb.ca.us.
