INTRODUCTION

The Silicon Graphics Image Format Library (IFL) 1.3.1 provides support for opening, reading, writing and creating image files in a format independent manner. IFL 1.3.1 includes support for the TIFF, GIF, PNG, JFIF(JPEG), SGI, BMP, PBM, PGM, PPM, XPM, XBM, FIT and Raw formats on all platforms. On IRIX, support for Photo CD, NITF, USGS DOQ, SGI movie file, QuickTime, Alias|WaveFront, SOFTIMAGE and YUV file formats is also included.
IFL runtime software consists of a primary library that provides the format independent interface. Additionally, a set of libraries used for supporting several file formats are included in the runtime subsystem.
Important note: for backwards compatibility on Irix, the IFL 1.0 libraries are included in the ImageVision Library 1.3.1 release. This allows applications linked with IFL release 1.0 to continue to run. However, to take advantage of new formats and bugs fixed since the IFL 1.0 release, you must recompile and relink against the IFL 1.3.1 libraries. IFL 1.3.1 is binary compatible with all of the IFL 1.1, 1.1.1, 1.1.2, 1.2, 1.2.1 and 1.3 releases.

CHANGES AND ADDITIONS

This section lists the changes and additions to the Image Format Library since the 1.1 release.

TIFF format updated

The TIFF file format has been updated to the latest version of Sam Leffler's software. Additionally, support for the GeoTIFF library has been added.

New formats

Support for BMP, NITF, XBM, XPM, SGI movie, QuickTime movie and old style DOQ files has been added. As of version 1.3.1, PBM, PGM and PPM are now supported on all platforms.

Names of .DLLs and .LIBs changed to protect the innocent

This change only applies to IFL for Windows. Unknown to the IFL engineering team, another product (CosmoWorlds) has been shipping it's own version of the IFL DLL's which are not compatible with this official version. To avoid this problem we have renamed all of the IFL DLLs and LIBS to have a '0' suffix. These DLLs are in fact binary compatible with the previous official version without the suffix. In the future, if a binary incompatible change is made, the suffix will be incremented. If you don't care about CosmoWorlds and want the bug fixes in this version for a product that is linked against the older DLL name, just copy the new DLLs over the version without the suffix. New and re-released programs that use IFL should be changed to use the new names.

Default install directory changed for IFL for windows

The default install directory used to be "C:/Program Files/Silicon Graphics/Image Format Library/". This has been changed to "C:/Program Files/Silicon Graphics/IFL 1.3.1/" so that multiple versions can be concurrently installed.

BUG FIXES

This section lists the bugs in version 1.0 through 1.2 that have been fixed in version 1.3.1 of the Image Format Library.

Appending iflRGBPalette images to TIFF files

When appending iflRGBPalette format image to TIFF file the color map was sometimes garbled (also when switching between sub-images). This has been corrected

Colormap generated in correct format for TIFF files

In previous versions the colormap could be written to a TIFF file in an incorrect format (not scaled to the full 16-bit range expected). This is now fixed and a warning will be issued when reading files with colormaps in the wrong format.

Cannot read FIT files > 4.2GB

Prior to version 1.2 the FIT file reader could not read files > 4.2GB (32 bit limitation). This limitation is no longer present in this release.

GIF support expanded

Support for animated and transparent GIFs was missing prior to release 1.2. These features are included in this release.

JPEG matching rule relaxed

The JPEG matching rule was relaxed to allow digital camera produced JPEG files to be read (these files are not fully compliant with the JFIF specification).

PBM and PGM support enhanced

Creation of PBM and PGM files is now properly supported; before version 1.3.1, files were created in PPM format instead. PBM files are now read in as bit data type.

KNOWN PROBLEMS AND WORKAROUNDS

This section lists the known problems in version 1.3.1 of the Image Format Library and, where known, ways to work around them.

Output to an image file in SGI format

Output to an image file in Silicon Graphics' classic .rgb format does not support arbitrary min and max values set. Use TIFF format if you wish to set arbitrary min and max pixel values.

iflXPMFile does not support symbolic color names

The XPM file reader does not properly handle symbolic color names. There is no work around for this limitation.