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Al Fasoldt's reviews and commentaries, continuously available online since 1983

Dealing with digital images, Part 4: Tips for good image editing


Feb. 2, 2000

By Al Fasoldt
Copyright ©2000, Al Fasoldt
Copyright ©2000, The Syracuse Newspapers

   Pictures you took with your digital camera don't have to look like pictures you took with your digital camera. They can look stunning.
   What the secret? I'll tell you five of them.
   Before we start. make sure your computer monitor is adjusted right. I told how to do that in detail in two previous articles (http://twcny.rr.com/technofile/texts/tec030297.html and http://twcny.rr.com/technofile/texts/tec030997.html) but I'll give you a quick summary here: Choose High Color or True Color (16-bit color or 24-bit color, respectively) for the display and make sure the brightness and contrast are adjusted right. (The articles on adjusting your monitor explain why most monitors are totally wacky and tell how to get brightness and contrast adjusted properly. Don't assume that you know, how to do this; the right adjustment is not intuitive, and might surprise you.)
   Then make sure you have a good image editor. I wrote about image editors last week.
   Ready? Now follow these five tips for improving digital images:
   1. Work on an uncompressed copy of the image, never on the original.
   2. Crop the heck out of the picture.
   3. Fix the colors so they look real.
   4. Get a grip on the gamma. (Don't worry. You're not going crazy. I'll explain this.)
   5. Don't be afraid to do weird things with the picture. (Yes, I'll explain this, too.)
   Let's consider these one by one.
   Work on an uncompressed copy, never on the original.
   Working on the original digital image is a bad idea always. Keep the original where it's safe -- in a separate folder on your hard drive, maybe, or, better yet, on a separate disk. (Don't use floppy disks even if your digital images will fit on floppies. Floppies are unreliable. Buy a CD-ROM recorder and save your images on CD disks if you have a lot of them. Blank CDs cost only a dollar.)
   By "original," I mean the picture that your camera originally took or the image your scanner saved. Obviously, since digital images are files and files can be copied perfectly, your "original"image can also be an exact copy of that first image.
   It's just as important that you always work on an uncompressed version of that image. Never, ever work on a JPEG (also called JPG) file. Use a BMP (bitmap) file. Repeat after me: Never, ever edit the JPEG version.
   Nothing makes a bigger difference than this. If you edit a compressed file, each time you change the image -- and you'll probably do that many times while editing it, right? -- you make it progressively worse. JPEG images are compressed by a "lossy" method -- a technique that gets rid of parts of the image to make the file smaller -- and that means each new version of the image looks worse than the previous one.
   You might not see these differences right away, so zoom into the image (enlarge part of it) and look at the details. Compare it with a completely uncompressed version to see the differences.
   This warning applies to more than JPEGs. Every image format that uses lossy compression is subject to the same problem. There are a lot of formats that use compression. Unless you already know about a format that works well and is not compressed, play it safe and use only the BMP format when editing your images. BMPs (Windows bitmaps) are not compressed and display very quickly. They can be gigantic, so don't be surprised if your hard drive fills up once you start working with a lot of BMP files. (A CD recorder makes sense, as I mentioned earlier, if you have a lot of large BMPs.)
   Crop the heck out of the picture.
   Cropping means trimming the picture to remove things that are distracting or elements that don't seem to belong. All image editors give you easy ways to crop.
   You take a photo of your mom in the back yard and you notice later that right above her head is a large branch that seems to be about to poke her in the noggin. Just crop it out.
   You shoot a picture of your cat arching his back in the doorway. The most important part of the picture is the cat. The doorway means nothing. Crop it out.
   You shoot a photo of your friend Betty. She has a wonderful smile on her face and her eyes are gleaming. Who cares what her hair looks like or what her ears are doing? Crop them out.
   Cropping makes the difference between a good photo and a good interesting photo. Practice it on copies of your pictures. Ignore the advice Elvis gave; be cruel. Crop out as much as you can bear, then take out some more. You'll be amazed at how your pictures will gain a new primary appeal.
   Fix the colors so they look real.
   Digital cameras are notorious for making colors look TV-ish and not very realistic. (Scanners do a lot better.) Make sure your monitor is adjusted right, then look carefully at some of your best photos from a few feet away. Are the faces the right color? Usually, they're not. Most of us forgive every color mismatch we come across except the color of faces.
   Use the color manipulation menus in your image editor to get the colors in faces right and the colors of everything else will follow. Remember: We judge the color of any scene that shows people in it by looking at their faces. Get the faces right.
   Want to know an inside trick? Professionals do this all the time. If the colors in your image don't seem right and nothing you do tames them, mute the colors. In some editors you do this by reducing the saturation. Others have a different term. Practice and you'll see what I mean. Muted colors always look more natural.
   Get a grip on the gamma.
   "Gamma" is a term that is widely misunderstood, and I'm not going to get into the fight here. Basically, my definition of "gamma" centers on how accurately less prominent areas of the image are portrayed. Areas that are bright might look fine and areas that are dark might be OK, but how well defined are the portions of the image that are partly in shadow? A proper gamma adjustment will help keep those "middle" areas from becoming too dark or too light. If your editing software has a gamma function, learn how to use it. If it doesn't, take care to keep the middle tones visible in some other way.
   Don't be afraid to do weird things with the picture.
   Let's say you have an image that is just not very sharp. It's well composed and the subject matter is interesting, but it's just not sharp. Is it a lost cause? Not a chance. Just add some fine noise, which in digital photography is nothing more than a lot of tiny random or evenly spaced dots. Many image editors have this function.
   Do this a half dozen times using different amounts of noise (and different types of noise, if you have a choice) to see the effect. When it's done right, the added noise looks like very fine film grain, and the tiny dots help our vision fill in the gaps in the picture. It looks like it's in better focus. It looks sharper.
   Do other weird things, too. Reverse the colors of a landscape photo or a nighttime picture. (Don't do it with shots of people unless you are really brave; the results nearly always look silly.)
   Lview Pro, one of the image editors I recommend, has a big collection of weird effects, so if you like that kind of thing be sure to try it. (There's a free trial period.)