7. Sizing up the Problem
One thing Preview can’t do is resize images... or can it? Actually, after a fashion, yes, it can resize images; it isn’t pretty and it isn’t sophisticated, but in a pinch, it’ll do.
The key is a clever use of the Scale field in the toolbar. Suppose that you want you to make an image one-quarter of its original size. Type 25 into the Scale field, and then press the Return key. The image is now scaled down to 25 percent of its original size. The problem here is that you can’t export the image at this reduced size. The workaround is to take a screenshot of the resized image, and use that instead. Press Shift+Command+Control+3 to copy a screenshot to the clipboard, and then create a new document (Command+N) into which the clipboard will be automatically pasted.
Use the crop tools to trim the image down to size. Magnify the image (using the zoom commands under the View menu) so that you can set the boundaries more accurately before cropping the image. The result: a new image that is 25 percent of the size of the original, ready to be saved into whatever format you require.
Figure 7 Zoom in to adjust the boundaries of the selection before cropping the screenshot down to size.