Photoshop Elements 8 for Windows: The Missing Manual

Resizing Images for Email and the Web

It's important to learn how to size your photos so that they show up easily and clearly onscreen. Have you ever gotten an emailed photo that was so huge you could see only a tiny bit of it on your monitor at once? That happens when someone sends an image that isn't optimized to view onscreen. It's easy to avoid that problem—once you know how to correctly size your photos for onscreen viewing.

The Image Size dialog box has two main sections: Pixel Dimensions and Document Size. You'll use the Pixel Dimensions settings when you know your image is only going to be viewed onscreen. (Document Size is for printing, which is covered in the next section.)

Figure 3-19. The Image Size dialog box gives you two different ways to change the size of your photo. Use the Pixel Dimensions section (shown here) when preparing a photo for onscreen viewing. (The number next to Pixel Dimensions—here, 34.3M—tells you the current size of your file in megabytes [as in this example] or in kilobytes.) Before you can make any changes here, you have to turn on the Resample Image checkbox at the bottom part of the dialog box (not visible here), since changing pixel dimensions always involves resampling (see Adding Canvas).

A monitor is concerned only with the size of a photo as measured in pixels, known as the pixel dimensions. On a monitor, a pixel is always the same size (unlike ...