Graphic File Confusion!

When many of us first started using computer graphics we knew all about the two types of graphics that a computer could produce: black & white and color! Now that I have progressed a little further in computer graphics, I realize that there are probably more graphic file types than any other kind. TIFF, GIF, APF, 3200, DHR, LoRes, EPS, paint, PICT, $C0, $C1, JPEG, etc. What a mess! This short article is not going to try to explain all the formats you might encounter, but I did want to talk about convers ion programs that you might find useful, and about the types of "foreign" graphics that you can use on a IIGS or 8-bit Apple II.

Three of the most commonly encountered graphic file types you will find in the libraries of online services like America Online or GEnie are GIF (Graphic Interchange Format), TIFF (Tagged Image File Format) and EPS (Encapsulated P ostScript--sometimes written as EPSF--Encapsulated PostScript File). GIF graphics can contain up to 256 colors, and can be a range of sizes, although 640 pixels by 480 pixels is a common size. This format was created by Compuserve so that members could e xchange graphics despite the wide variety of computers that were represented. There are two main "flavors" of GIF, 87a and 89a, the main difference being that in the 89a type, notes can be included with the file. You can view and convert GIFs on Apple II e's or IIc's with the freeware program IIGIF, by Jason Harper. This program does have problems with the 89a type of GIF, but works well with the 87a. Using the program allows you to view GIFs and to convert them to DHR graphics. On a IIGS, you can use tw o other programs, SuperConvert (a commercial version of Harper's shareware SHRConvert) by Seven Hills software, and Prism, by New Concepts, Inc. Both of these programs allow you to view and convert GIFs. With SuperConvert you can save a file as a GIF, or convert a GIF into a TIFF or a 16 color Super HiRes graphic. Using Prism, you can save the graphic as a 16 color, 256 color, or 3200 color Apple Preferred File graphic.

TIFF files are bit-mapped images that can contain up to 16.7 million colors! Many scanner programs for the Macintosh and Windows save in this format, as do many commercial programs. As mentioned above, SuperConvert on the IIGS can save a file as a TIF F, and Prism can convert TIFF files into IIGS files. In addition, Quick Click Morph, reviewed in this issue, can import TIFF files for use in creating morphs. The practical side of this, even if you don't have QC Morph, is that with Prism you can use TIF Fs that you download or that you get on CD-ROM on your IIGS. Or, if there is a scanner in your school connected to a PC or Macintosh, you can convert scans for use in your IIGS programs such as HyperCard IIGS or HyperStudio.

EPS files are created in one of two ways: with a drawing program on a PC or Mac such as Adobe Illustrator or Macromedia FreeHand, or by typing in the PostScript commands in a text editor. You have probably heard of PostScript in connection with laser printers. PostScript transcends printing, however--in fact, it is a programming language that is used to describe images. Printing is a natural application for this, but there is also a Display PostScript that can be used to create images on screen--whic h was a feature of the NeXT computers created by Apple founder Steve Jobs. PostScript files are actually just text files with the instructions that the printer needs to create an image on page. EPS files can be used in two ways on the Apple II--in the de sktop publishing program Publish It! and with a program that can download postscript files to a laser printer, such as LaserBeam or a telecommunications program such as ProTerm.

To be used on an Apple II, the postscript file needs to be a text file. Macintosh--generated EPS files often have additional information that allows the file to display a low resolution pict on screen; these picture resources need to be stripped off t o be useful in Publish It! or a telecom program. On the IIGS, the easiest way to do this is using the text editor NDA ShadowWrite, which has a powerful "Open Any" command that can be used to open only the resource or the data fork of a file. By opening o nly the data fork of an EPS file, and saving it as a separate text file, the graphic becomes usable by Publish It! Of course, you could simply learn some of the PostScript language, and type in your graphics. In fact, if you have a text editor and a Post Script printer, you have all you need for a good programming courseŠonce you get the references to PostScript so that you know what to type in!

So there you have it--three "foreign" graphic file types that you can use on your Apple II computers. Don't feel left out then, because as Apple II users have been showing for years, there is little that is impossible for our computers given a little ingenuity--something that Apple II users have in abundance!

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