Often scanners and digital cameras come with computer programs that help you "touch up" digital images. Some help reduce your image file if it's too big, some automatically remove the red shine from people's eyes in snapshots, some have special features like "automatic contrast," etc. In my opinion, these programs are completely inadequate for those of us wanting really good images. Moreover, I'm sorry to say it but a good graphics programs can cost more than a scanner or a camera.
If you want to download a freeware graphics program that can reduce your file size a little and do a few other things, but still isn't all that great (it's free, after all), do a search on the keywords "freeware graphics program." One I've used is XNView.
Adobe Photoshop is great, but expensive. One feature I really like about Photoshop is its "Save for web" button. This special "save file" option is configured so that it automatically removes information not absolutely needed for a picture of the size and sharpness appropriate for computer screens. If you take an image that has been saved with this option and try to make a glossy print from it, it'll be fuzzy and not pretty at all but, on the computer screen, it can look great.
After you have an image in a file of a decent size, all the rest is easy. You just need to know how to use your graphic program. However, good programs are so powerful and flexible that it can take a while to learn them. Certainly you should take your program's "tour" or use its "tutorial."
Let's say we're starting with the above picture of ants on a window, which was taken with a good digital camera. The image file it produced was originally 1,928,000 bytes large -- 1.9 MB. Once the file had been downloaded from the camera into my computer and I first viewed it on my computer screen it was so large that I could see only a tiny part of the picture.
Fact is, the average digital camera or scanner produces images entirely too large if all you want to do is to view the images on your computer screen or post them on the Web. Think about this: The image at the top of this page has been reduced from the camera's original 1,928,000 bytes to 4,720 bytes -- which is 4.7 KB or about 0.005 MB. In other words, the camera produced an image over 400 times larger than I needed!
However, that's not all bad. For, the image was so large that I was able to crop out all but the image you see at the right. That is the bottom ant in the group of three ants seen in the picture above.
So, that's one thing any graphics program should do -- crop out small sections of a picture and enlarge them. Another is to take that too-dark picture at the right and lighten it, which I've done at the left. Also, I didn't need such a large picture, so while I was at it I reduced the size a little more. Now we've cropped the picture, lightened it, and reduced it. But there's still much more a good graphics program can do.
At the right I've done two more things. First, in the lightened image above, see the other ant's blurry leg entering from the top? I used Adobe Photoshop 5.5's "Rubber Stamp Tool" to paste a part of the background there that didn't have a blurry leg in it.
Second, using the "Linear Gradient Tool" I put the ant on a rainbow. Well, with a good graphics program like Adobe Photoshop 5.5 you can keep fiddling with an image like that all day. What you see at the right is pretty different from the original picture at the top, no?
Another tool I like a lot is the "add text" function, an example of which is shown at the left. In Photoshop you just place your cursor where you want the text to begin, then you click on "T" in the "toolbox," then you choose the size, kind of font, and color of text you want, and type your words. When you click on "OK," then there's your text already there, and you can easily alter it if it's not exactly right.
Finally, if you think you'll ever want to put your images onto the Web, save your images in JPG format. However, if you are producing charts, maps, graphs or something of that nature with few colors, then use GIF. All the pictures on this page are JPGs, but the colorful word "GRAPHICS" in title at the top of this page is actually a GIF file.