Digital Photography August, 1988 ------------------- By Jim Maxey Digital photography is another method of making computer graphics, but the difference between these types of graphics and "digital photography" is quite dramatic and very exciting! Digital Photography is not new to computers even though it may seem so. Over the past year many advances in technique and technology have greatly improved what can be displayed on a monitor and printed on a dot matrix or laser printer. And now that Compuserve has created the GIF format, most micro computers may now view and exchange pictures created on different kinds of systems. That's one of the differences. The images are still the same images but once converted into the GIF format they can then be displayed with machine specific programs. The resultant image is simply in the GIF format. The GIF concept has been placed in the public domain. However, the images and display programs may or may not be copyrighted. That depends on the author if the display program and the author (creator) of the image. Essentially, digital photography means taking a print, slide or video source and capturing and converting it into a binary file to be displayed on a computer monitor by your system's video card. This "digitized" image is treated as an array of tiny dots (called PIXELS (PIXture ELementS)) and is displayed on a screen by building up a framework of these dots. The assorted graphics modes vary in how many dots there are on a screen, which is called the "resolution." A typical medium resolution mode for the IBM PC has 640 columns of dots across the screen and 200 to 350 lines of dots down the screen. Any kind of picture can be made of these dots, color or black & white (monocolor). But what really makes the difference is the amount of colors available in any one digitized picture. That's why 256 color images are becoming so popular. They can appear to be nearly broadcast quality. The 256 colors fool the eye. The resolution may be low at 320 X 200 but you'd swear you're looking at a much higher resolution screen. And with the higher resolution of 640 X 480 X 256 (and even higher) the future looks very bright. It's all very exciting, especially now that VGA cards are available to be used in the standard XT, 286, or 386 computer. 16 color images have been greatly improved too. What you would have seen just a year ago with the standard IBM EGA resolution with images on a computer can now be seen as very life-like pictures on your 640 X 350 X 16 system. I know first hand. I've been digitizing pictures for the last three years and have seen what can be done. Macintosh used to rule the consumer digital arena but now with HiRes color standard on computers like the Amiga and Atari St (and now IBM) those b&w images don't have the same lure as before (at least not with most of us). We can't completely explain it but there is something so exciting about being able to display real images on your computer, bring them into graphics PAINT or Desktop Publishing programs and shrink, enlarge, twist, or manipulate the photo in many ways. You can blend one picture into another, shrink images to small size and fill your screen with a host of individual images. Some "paint" programs are sophisticated enough to allow inexperienced amateurs to create "works of art". Perhaps you'd like to display your images within a slick slide program, unattended, where images fade from one to another. Or maybe you'd like to print pictures in b&w or color, make postcards, Christmas cards, digitize the face of an employee for a company news letter, or, perhaps you just want to view your picture as it sits there, ready, waiting, and willing to be manipulated. But why the interest in "Digitized Photography"? What's so special about being able to display realistic photographs on your computer? Why not simply turn on your television set or look at a magazine or turn to your family album? Of course, the answers vary as much as individuals. Here are some "answers" you might consider: (a) The television screen is "interlaced". When you closely view a video image on your television screen you'll notice it jumps around and that it's filled with little sparkles technical people call video noise. One of the reasons this "noise" exists is that the image is usually being broadcast or cablecast along analog lines which are quite susceptible to noise. Also, NTSC television is a mixture of the Red, GREEN, and BLUE elements of the original picture. It's brought together in an ingenious method to save bandwidth in the electromagnetic spectrum. This is fine but the results as seen on your home (of even in the broadcast studio) tv can be much less than desirable. Another problem you may be aware of is "Strobing and Bleeding". Have you ever heard the term? It's inherent in composite video. You see it every day and have become use to it. Have you ever seen a person wearing a plaid shirt or dress or a video scene where diagonal colors seem to be floating through the picture. Broadcast engineers hate it and plead with producers and directors to avoid it if at all possible. The problem can be licked by using RGB analog cameras and video processors but eventually down the line the signal is converted to composite where the Red, Green, and Blue elements are combined. This is where the problem originates. So why is it a problem when one considers digitizing? The answer is easy. When one "grabs" the video screen in real time you are actually grabbing one frame (in most instances). And you end up with what is actually on the screen; all the information present, including those diagonal colors that are seen as red, green, and blue fringing in outlines of the subject. Graphics artists have a great problem and there are only two ways to eliminate the it. One is to edit out the color garbage in your CAD program. This is time consuming and painstaking. The other option is to use an RGB camera and a digitizing and software that allows you to treat each of the three colors separately. In this way the Red, Green, and Blue signals don't have a chance to "beat" against one another and the resultant image is virtually free of the color bleeding and diagonal color garbage. Also, the signal to noise ratio is generally much higher with RGB cameras and equipment so the resultant image digitized is cleaner and sharper. With composite digitizers the more detail you have the more color fringing problems you will see. With RGB cameras, this is just not a problem. So, because of this, viewing the best digitized (or scanned) images means that your image is going to "stand still" for you. It's almost like viewing a print or even a slide. (b) Digitizing images is another way to save your prints or slides for future viewing. Of course, making a copy of a binary picture means that there is no loss. Make as many copies as you wish and the 100th generation will be as faithful to the original as the first copy. There is no fading of colors over the years, no possibility of scratches, wrinkles, or fingerprints (providing of course that you take care of your binary images and be sure to back up your "copies"). (c) For me though, the main reason I enjoy digitizing pictures is the ability to manipulate them. They are YOUR images. You have digitized them. Even if they were originally photographed by another person, the conversion to binary form can be very personal and quite enjoyable. We all love our computers. They have become part of us (much to the disfavor of our spouses). Let's face it. Who do you turn on mostly these days? Your friend the computer (whatever pet name you may have for it (her/him) or your spouse? What is the first thing you do in the morning? The last? Okay, now that that's settled, we agree that we have become personally involved with our computers. Now, let me suggest that it's really not your computer! It's you. (no letters please, I don't have time to answer). Yes, my friend, your computer is really not alive, sorry to report. Your computer is you. Nothing less or more. It represents (or can) what you are or want to be. It's very personal. You control it. That's the way it should be. That's the way it was designed. Yes, I know, sometimes we think they are controlling us, especially when you swear you're going to wring the neck of some programmer who can't write instructions. So, you are in control of what you see and do. You tell the computer how you want to digitize your pictures and how they will be displayed, how large they will be, what color, shape, and when. Then of course you can print the lovely picture for those less fortunate than you who either don't have a computer, can't view your works of "art" or who may be for some silly reason "afraid of computers". Heavens forbid. So what can you do with your digitized image? Depending on the software/hardware you have, just about anything you can imagine... and then some. Remove the head from one person and nicely fit it onto another? Sure. Easy. And if you take a few minutes you may never tell the difference. Unless you put Ronald Reagan's head on Madonna. Well, there's an idea. May have some redeeming possibilities. Of course, there are endless other reasons why we use computers and digitize photos. You can fill in your own ideas. The cost of digitizers has been dropping in the last year. One can now buy an excellent digitizer for the IBM PC (EGA/VGA) at around around $600 (not including software or camera). The only thing left is for you to decide what you want to digitize then zoom your lens into your subject, compose it, adjust the contrast and brightness and hit the key to "Digitize.....".