Before resizing your image, try to anticipate how it will be viewed. If you plan to e-mail the image, it should fit into a standard browser window. In this case, make the image no wider than 600 pixels (the height does not matter here), and set the image resolution at 72 ppi, since this is the most resolution a computer monitor will display. But if your client will need to print the art to, say, a desktop color printer, set the resolution to roughly 150 ppi.
Crop your image to keep the best parts, rotate creatively, straighten crooked lines, or simply set the final size. The Crop tool in Photoshop will do all of these tasks very effectively.
Alternatively, you can crop the image and then use the Image Size dialog (Image>Image Size) to specify the final dimensions and resolution. Use the Bicubic Sharper option (available in Adobe Photoshop CS and higher) to keep the image looking sharp despite the (sometimes drastically) reduced size. Tip: Save yourself some time by creating an Action to replay these settings on every image that will be saved for this medium.
Size and slice
If you are prepping a high-resolution file for uploading online, learn how to slice an image. Slicing is a way to make a large image load as many smaller ones, making it appear to load faster. You can also use the slicing feature in these programs to optimize some parts of the artwork differently from the rest. For example, a part of an image that contains photographic imagery might compress better as JPEG slices, while a text-heavy part of the image can be optimized as GIF slices. A slice can also contain hotspots and links.
Select a color standard
Images that are to be viewed on screen still need to be edited for contrast and color flaws. The first order of business is to set up some basic parameters for the display of colors in the image. This is because there isn’t any “standard viewing environment” on the web, nor will e-mail applications and browsers color-manage your artwork to your satisfaction. A common approach is to convert the colors in the artwork into a smaller color space that will display colors in a somewhat muted, albeit consistent fashion to all viewers.
Choose Convert to Profile from the Edit menu in Photoshop CS2 (in previous versions, choose it from the Image>Mode menu), and choose the sRGB IEC61966-2.1 profile as the destination color space. This color model represents all the colors available on any standard monitor, which makes it a suitable “one-size-fits-all” choice for this purpose.
Correct tone and color
This is where you can let your artistic talents shine. Unlike in correcting print images, you need not set up highlight/shadow endpoints, as these images will not interact with ink and paper. You can use your favorite tools to create pleasing exposure and color balance in your images.
One of my favorite techniques for creating professional-looking art under a deadline is to use the automatic color correction options available in the Levels/Curves dialog in Photoshop. Click the Options button in either of these dialogs and experiment with each of the three settings in the dialog. I’ve found that most images are enhanced by using one of the last two items (Enhance per Channel Contrast or Find Dark & Light Colors), especially when combined with the Snap Neutral Midtones setting.
Photoshop CS2 gives us a nifty feature called Exposure, which lets you make minute changes to the exposure and mid-tone scale of an image. Choose Exposure from the Image>Adjustments menu.
Whenever you reduce the size of an image, you’ll need to add some sharpening to enhance the details in the image. In Photoshop CS2, you can use the new Smart Sharpen Filter to add prodigious amounts of sharpening to your images, while minimizing sharpening artifacts and halos. As in earlier versions of Photoshop, you can use the Unsharp Mask filter to enhance contrast along the color transitions in the image. Tip: Apply sharpening to a duplicate layer for greater flexibility, and view the main subject at a 100 percent zoom to verify that it is not over-sharpened.