Select “Write GIF as” from the File menu, or press Command-G to write a copy of the GIF picture being currently displayed. You can use this to make copies onto your hard disk (or a floppy disk) of favourite pictures that you see whilst scanning a CDROM. In effect, this is the same as making a note of the file name, and using the Finder to copy the file from the CDROM to your disk. Please note that you should not infringe any copyright that might pertain to the image being copied.
File formats—GIF or TIFF
When writing a copy of a GIF picture you are given three choices of file format:
• GIF (Graphics Interchange Format) — this is the fastest and probably the smallest option, fastest because it is just a copy of the original GIF picture, which is already compressed. Smallest because GIF pictures are always stored internally with LZW compression.
• TIFF — use the TIFF (Tagged Image File Format) if you want to import a copy of the picture into a word processor, desktop publishing program, or graphics program that does not support GIF pictures. TIFF pictures are more widely supported than GIF pictures, particularly by Macintosh programs. Once you have decided to use the TIFF format, you have a choice of compressed or uncompressed files.
• TIFF compressed files are saved using LZW compression (similar to GIF pictures). A TIFF compressed picture will be a similar size to a GIF picture. The compression (and decompression later on when loading the picture into another program) makes this format slightly slower to use than uncompressed TIFF images).
• TIFF uncompressed files tend to take two to three times as much disk as TIFF compressed. However they are faster to save, and load later on. Also, some other programs may not support TIFF compressed pictures. If you cannot load a TIFF compressed picture into another program, try the TIFF uncompressed option.
Only GIF pictures can be saved
At present, you can only save copies of GIF pictures as described above. Although this version of GIF Slideshow can read TIFF, MacPaint and PICT files as well, it is not designed to save copies of those formats. The reasons for this are:
• Most word processors on the Mac already support the other file formats, as they are mostly “native” formats (especially MacPaint and PICT), so it is already possible to load such files into word processors and desktop publishing programs.
• There are already other excellent “conversion” programs around, including ShareWare ones, so to add general file conversion into GIF Slideshow is somewhat of a duplication of effort.
• To successfully cross-convert from every format to every other one (e.g. TIFF to MacPaint) would require considerable additional code in GIF Slideshow, thus making it larger and more prone to bugs.
• Converting from colour formats (e.g. GIF) to monochrome formats (e.g. MacPaint) also requires some method of “dithering” or otherwise converting the colour information to black-and-white. This also adds complexity.
• GIF Slideshow is intended to be a fast, easy-to-use viewing program. The author’s future efforts will be directed to improving it in that direction.
