XLOADIMAGE - X11 Image Loading Utility WHAT IS IT? This utility will view several types of images under X11, load images onto the root window, or dump processed images into one of several image file formats. The current version can read many different image file types; for a complete list type "xloadimage -supported". A variety of options are available to modify images prior to viewing. These options include clipping, dithering, depth reduction, zoom (either X or Y axis independently or both at once), brightening or darkening, and image merging. When applicable, these options are done automatically (eg a color image to be displayed on a monochrome screen will be dithered automatically). TIFF AND JPEG SUPPORT This version of xloadimage supports both JPEG and TIFF files through the IJG V4 JPEG library and the Sam Leffler's V3 TIFF library. The libraries are included almost in their entirety. The libconfig.c program is used to create appropriate Makefile configurations so that no special intervention is required to compile these libraries on most systems. If there are problems compiling these libraries on your system you can leave out support for them during the configuration process. In my tests on various machines there were never any problems building the supplied libraries. Unfortunately I cannot answer most questions regarding these libraries. You can direct such questions to: firstname.lastname@example.org email@example.com BUILDING THE RELEASE To build xloadimage simply type "make". If you prefer to use xmkmf or imake, please read the note below before doing so. Xloadimage will build a configuration program first and run it -- the configuration program will look at your system to try to determine what variety of system it is, where the X libraries and include files are, and whether or not some nonstandard libraries are likely to be needed. The configuration program is specifically designed to make the configuration process very painless on most systems available today, but it cannot predict all possible variations. If the configuration program cannot find something that it's looking for it will ask you where it is and it will attempt to verify the correctness of your response. You will also be prompted for the name of the C compiler you want to use, and where the TIFF and JPEG libraries and header files are located. The questions should be simple and straightforward; if you don't know the answer to a question you can usually hit "return" and the default will work. If you make a mistake during configuration you can interrupt the configuration program (using ^C or whatever the interrupt character is on your system); type "make" to restart. If you are building xloadimage on multiple systems you should type "make clean" to clean up the build on the previous system; the configuration will be re-run when you type "make". Once configured the xloadimage distribution will continue to use the same configuration parameters until a "make clean" or "make configure" is done. All configuration options are written into Make.conf; if you need to make changes and don't like the configuration utility you can always edit the file yourself. Keep another copy of any such changes because xloadimage will overwrite Make.conf whenever you do a "make clean" or if it needs to rebuild the configuration program. NOTE: The Makefile assumes that "cc" exists and can be used to build the configuration program. If your C compiler isn't called "cc" or is not found along your path you will need to edit the CC= line in Make.conf to provide the appropriate compiler name. NOTE: Many sites use the xmkmf to generate an appropriate Makefile from an Imakefile when building X applications. While xloadimage includes an Imakefile for this purpose IT IS STRONGLY RECOMMENDED THAT YOU DO NOT USE XMKMF OR IMAKE. There is not enough information included in the MIT releases to determine the appropriate configuration for xloadimage. For this reason some capabilities cannot be configured using xmkmf/imake. If you decide to use xmkmf and/or imake anyway and you have problems building the distribution you should copy Makefile.std into Makefile and follow the normal installation instructions. NOTE: If you are on a VMS system the automatic configuration code won't work at all. There is a VMS_BUILD.COM script included which should be close to what you need to build xloadimage. Unfortunately I cannot test this script so it may not be perfect -- you're on your own if you're using VMS (which is probably not surprising if you've done this kind of thing before). INSTALLATION After compiling and installing xloadimage, I recommend linking or symlinking to the executable with the names "xview" and "xsetbg". The default behavior is slightly different when invoked with these commands (they're also easier to type). If you have a public image area you should consider setting the SYSPATHFILE option in the makefile and setting up a system-wide configuration file. See the man page for information on the format of this file. IMPLEMENTATION Most functions are not particularly fast, and some functions use simple-minded algorithms deliberately over more advanced ones. I stressed portability over all and simplicity over performance, although many algorithms have become fairly complex over time. I believe the result is a usable, portable tool which should serve the needs of most users. The source code is basically in two parts: image manipulation routines and everything else. The image manipulation routines should be completely independent of X, thus allowing people to use them under other graphical systems. No guarantees here, but I tried. Performance-oriented people will notice that some operations are redundant. Xloadimage is designed to work fairly quickly for most operations but in some cases I opted for a cleaner internal design rather than pure performance. OWNERSHIP AND COMMERCIAL USE I used a modified version of the MIT X Consortium copyright with all of these functions, thereby allowing full freedom with the code so long as the copyright notices remain intact. All contributions have similar notices. Commercial sites are welcome to use the code even without special permission, licensing or royalty fees. I'm very happy to hear of this stuff going toward real products (it's in several that I am aware of) so I appreciate hearing of any use of some or all of the code in other applications. If you tell me you're using it I'm much more likely to keep you informed about new versions as well, so it works out well all around. Xloadimage does not require any form of licensing or royalty payment to use in a commercial product, but the MIT copyright does require mention of the copyright notice in accompanying documentation; xloadimage has several copyrights that may need inclusion. It's unlikely that I would ever prosecute someone for neglecting to follow the terms of the copyright. If you're using xloadimage in a commercial product beware that it adds handlers for common exceptions that print out my email address. While I'm happy to support any xloadimage user it is difficult to support them if I don't know about changes you have made. At the very least modifications should include changes to the patchlevel information to indicate your company and/or product name even if you do not change the email address. PRAISE, SUGGESTIONS AND BUG REPORTS Praise, suggestions, and bug reports should go to: Jim Frost CenterLine Software 10 Fawcett Street Cambridge, MA 02138 (617) 498-3000 firstname.lastname@example.org Please include the version number and sample image data if you are reporting a bug. Functions implementing new image types are welcomed; mail them to the same address and I'll do my best to distribute them. Please include a small sample image. Try to send them as public domain so I can keep the number of differing copyright messages to a minimum -- I'll use my standard message and leave the implementor's name and information in the file for credit. I wouldn't copyright this stuff at all except that it's a requirement for X11 distribution. If you particularly like xloadimage, feel free to drop me a line. It makes me feel good and I get a feel for who does what with it, which sometimes influences what parts are worked on. THANKS Special thanks to the crew at the Boston University Graphics Lab for their assistance and sample images, and to email@example.com for his simple dithering algorithm (or what's left of it). Real special thanks to Kirk L. Johnson (firstname.lastname@example.org) for a very nice GIF loader and dithering routine, to Mark Snitily (email@example.com) for 386/ix compatibility work, to Andreas Stolcke (firstname.lastname@example.org) for miscellaneous bug fixes, to Anthony A. Datri (email@example.com) for a number of things, to Mark Moraes (firstname.lastname@example.org) for the slideshow colormap fix, to Gregg Townsend (email@example.com) for a suggested dithering routine and other fixes, to Brian Frost (B1F5814@RIGEL.TAMU.EDU) for changes for VMS, to Chip Horstman for G3 FAX support, to Deron Dann Johnson (firstname.lastname@example.org) for fixing the RetainTemporary bug, to Tom Tatlow (email@example.com) for image rotation code, to Mark A. Horstman (firstname.lastname@example.org) for tilde expansion in .xloadimagerc files and virtual-root support in root.c, to Tim Roper (email@example.com), Graeme Gill (firstname.lastname@example.org) for gamma correction and Utah RLE image support, Mark Majhor (uunet!sequent!markm) for FBM and MacPaint support, Ian MacPhedran (email@example.com) for PGM and PPM support, Per Fogelstrom (firstname.lastname@example.org) for a fix to send.c, Hans J. Albertsson (hans@Sweden.Sun.COM) for cleaning up GIF aborting, Graham Hudspith (email@example.com) for a geometry patch, Glenn P. Davis (firstname.lastname@example.org) for McIDAS areafile support, Keith S. Pickens (maxwell.nde.swri.edu!ksp) for fixing the RLE loader to work with the updated zio package, Mike Douglas (email@example.com) for normalization, Rod Johnson (firstname.lastname@example.org) for speedup suggestions, Hal Peterson (email@example.com) for his Imakefile fix, Matt Caprile (Matthew.Caprile@ec.bull.fr) for slideshow delay code, Bob Deroy (firstname.lastname@example.org) for mondo 24-bit Sun Rasterfile images that broke everything, Christos S. Zoulas (email@example.com) for a first-cut 24-bit implementation, Gerald James Barnes (firstname.lastname@example.org) for a first-cut forced-visual implementation, Michael Campanella (email@example.com) for more VMS changes, Kee Hinckley (firstname.lastname@example.org) for robustness changes to the g3 and MacPaint loaders and the ZIO package, Tim Northrup (email@example.com) for PC Paintbrush and GEM image formats, Richard Weidner (firstname.lastname@example.org) for lots of 24-bit testing, Eckhard Rueggeberg (email@example.com) for a better PCX loader, and any others whose names I've missed. HISTORY Patch 01 contained a new Makefile.std, Makefile.gcc, and Imakefile. It contained a bug-fix to sendImageToX() which allowed bitmaps to be sent from little-endian machines (eg VAX, 80386) correctly, and a fix to xbitmapLoad() to allow correct loading of X10 bitmap images. An enhancement to imageInWindow() which allowed exiting from image windows by typing 'q' was submitted by Chris Tengi (firstname.lastname@example.org) and was included. The previously missing file 'patchlevel' was included. Patch 02 contained modifications to the Makefiles, support for the X Pixmap image type, a different dithering algorithm that didn't blow the image up (with the old one moved to halftone.c), and a bug fix to zoom.c to correct problems when zooming bitmaps. Patch 03 contained a new loader for GIF files. The dither bits array in dither.c was changed so it worked properly, and both dither.c and halftone.c had minor bugs fixed. Merge.c was modified to correct bugs when merging RGB images. Pbm.c was modified to handle raw format images. Root.c was modified to deny image loads which would change the root window's colormap. Send.c was modified to use shared colors whenever possible and to handle color displays which have depths which are not a multiple of 8. Window.c was modified to avoid deleting the default colormap, allowing proper operation on some servers prior to X11R3 patchlevel 08. There were many miscellaneous bug fixes. Patchlevel 04 contained an enhancement to root.c to use RetainTemporary and KillClient(disp, AllTemporary) so that it could clean up after itself when reloading. The -quiet and -zoom options no longer cause garbage to be displayed for the image title. A small bug in new.c that caused incorrect allocation of bitmap images was fixed. Several calls to XCreateColormap were missing the "visual" parameter in send.c; this was fixed. A bug relating to -border and monochrome displays was fixed. There were several changes to the Imakefile and Makefiles. Patchlevel 05 contained enhancements to allow slideshows and fullscreen viewing, some bug fixes related to scrolling around within images, Saber-C makefile enhancements, a bug fix to the halftoning title, and the addition of greyscale Sun Rasterfile support. Patchlevel 06 contained support for G3 FAX images, bug fixes to merge.c to fix some signed/unsigned errors and clipping problems, changes to root.c to make previously allocated resources be freed properly, and a completely new dithering routine. Version 2, patchlevel 00 contained support for MacPaint, FBM, PGM, PPM, CMU, Utah RLE and XWD image formats, gamma equalization, image smoothing, and image rotation. G3 FAX support was modified to cut down on false positive identifications. The zio subsystem was modified to cache reads for performance improvements and to allow stdin to be used as an input source. Several loader functions which did not properly close their files were fixed. Color slideshows now work. Icon titles use an abbreviated titlebar title to enhance readability. The resource class name was changed from XLoadImage to xloadimage to be more predictable. Several options now propagate to all images following them if the -slideshow option is specified. Version 2.01 contained several fixes to window.c to work around a bug in twm/tvtwm which could crash servers. The resource class name was changed (again) to Xloadimage to conform with standard class naming practices. Several problems with System-V compilation were corrected. The gcc-1-37 make target was fixed to prevent a double-define. The GIF loader was patched to respond better to short GIF files. The Utah RLE image loader was patched to work with the updated ZIO package. Version 2.02 added the options -default, -gray, -normalize, and -private. The memToVal routines were macro-ized for substantial speed increases. The atom used for deleting previously allocated colors for the -onroot option was changed to correspond to that used by xsetroot. Dithering and halftoning were changed to use a lookup table for intensities to speed them up somewhat. Rle.h was changed to use memToValLSB() instead of its own byte-swapping algorithm for portability. Window.c was modified to eliminate the initial paint, moving it instead to within ConfigureNotify. A fix was made to xwd.c to fix its colormap loader for out-of-order colormaps. The G3 FAX identification function was fixed and the G3 loader moved to prior to the MacPaint loader so that both can be used. A bug in send.c where color images using the default colormap would not appear correctly if the display depth was not a multiple of 8 was corrected. The default gamma value used in rle.c was changed from 2 to 1. There were miscellaneous portability changes. Version 2.03 added -delay. Many minor programming errors were cleaned up. Hash.c was changed to use image.h instead of local typedefs (fixing a problem with PPM image loading). Window.c was changed to fix a problem with override redirect windows in fullscreen mode, and refresh problems with some servers in slideshow mode were fixed. Path.c was modified to ignore directories when searching for files. Send.c was modified to allow TrueColor and DirectColor visuals. Version 2.03-JPL contained interim code to handle 24-bit TrueColor and DirectColor displays pending the release of Version 3.0. Version 3.0 added full support for all server types. Internal support for 24-bit images was implemented (including the improvement of Sun Rasterfile and PPM support to use the 24-bit format internally). Many modifications to image processing routines to support or make use of 24-bit images. A much-improved colormap reduction algorithm replaced the primitive one in previous versions. The window display code was modified to work with the best possible visual. The window display code was modified to use backing store when available (and -pixmap was added to force the old technique). The -fit option was added to force an image to be fit into the default colormap if it didn't fit as supplied. The -fork option was added to allow automatic backgrounding. The -onroot -fullscreen options were modified to preserve aspect ratio. The -windowid option was added to allow the setting of the background pixmap of any window. The -onroot code was modified to work with DECWINDOWS servers. The -normalize option was improved for color images. The -slideshow option was removed (and made the default behavior) and -merge was added to allow more flexible image merging. The WM_DELETE protocol is now recognized. PC Paintbrush (PCX) and GEM bitmap image formats are now supported. The GIF 89a signature is now recognized (although no support for its additional capabilities has been implemented). Version 3.01 corrected color problems when merging RGB files and fixed a few small problems. Version 3.02 fixed a -zoom bug for 24-bit images, a bug in the imageOnRoot() function for DEC and NCD servers, and a couple of bugs in merging and smoothing. Version 3.03 added JPEG and color PCX image support and small fixes to smooth() and normalize(). Version 4.0 added color PCX support, VICAR image support, NIFF image support, -dump, -unhalftone, JPEG V4 and TIFF V3 integration, generic filtering, and fixed a lot of bugs and minor build problems on some systems. Options are now handled in the order they are given rather than a fixed order. G3 FAX loader was removed because it was totally unreliable. Version 4.1 fixed a number of ANSI-C compilation problems, enhanced the automated configuration to target HP and SGI machines automatically, corrected a few minor bugs, and included the IJG JPEG V4A code.