Building a Web Site For Dummies®, 3rd Edition

Editing Images

There are plenty of times when you’ll need to tweak an image in order to get it “just so” for your site. All graphics programs give you some options for doing this sort of thing, and they all work pretty much the same way. In this section, I show you how to use a handy little graphics editor called IrfanView (www.irfanview.com) to spiff up your Web graphics quickly and easily.

A fully functional copy of IrfanView is included on the CD-ROM that accompanies this book.

Resizing

Although you can make an image appear smaller on a Web page than it really is (see the “Sizing images in HTML” section, later in this chapter), it’s usually best to deliberately set the size before it ends up on your site.

This is a simple process, although there are a couple of caveats. When you resize an image, your graphics program has to change the pixels — the color dots that make up the image. Obviously, a larger image will take more pixels and a smaller one will take fewer. This means either adding pixels (interpolation) or subtracting pixels (resampling).

Although graphics interpolation has come a long way, any image resizing process still has to make some compromises. Shrinking an image usually doesn’t result in any damage to the ability to view the picture, but it always has to mean some loss of detail. Enlarging an image can add areas of blockiness due to the additional pixels needed ...