Preparing images for the screen

This tutorial talks general about how to prepare your images so they look good on the screen. It isn't designed for you to follow along. Once you read it, you should then read either "Preparing your images for the screen using Photoshop Elements" or "Preparing your images for the screen using iPhoto" If you don't have either of these two programs and you aren't sure which one your picture editor is most like, read "A short introduction to iPhoto" and "A short introduction to Photoshop Elements" to decide.

The simple version

The images on your cd are high resolution (hi-res) images. That means they are several megabytes in size and have lots detail. They are ideal for printing. If you plan to send them to someone via email, use them as wallpaper or post them to a file sharing site, they have too much detail! So you need to “down-res” (or down-size) them. Before you down-size your images, you should first perform any necessary corrections on them. Most of these corrections are very easy to do and you don't have to understand the principals behind them to get good results.

This is what you need to do to your photos to prepare them for the web.

1. Rotate the image 90° counter-clockwise
2. Crop the image as desired
3. Perform an auto-enhance command (all picture editors have them)
4. Apply a slight sharpening, if your picture editor has that function
5. Change the image size to something smaller
6. Save your changes

If you want more information about why you should do these things, read on:

Rotating

Most -- if not all -- of the pictures on your CD will be taken in “portrait” mode which means the very first thing you have to do is rotate them 90° counter-clockwise so that the subject is upright. All pictures editors have a Rotate command.

Cropping

If you want the subject to be bigger and centered in the frame with less of the distracting background, you should crop your image. All picture editors have a crop command.

Enhancing the color and exposure

Indoor lighting can be tricky and it's possible that your image may have a color cast. It also may be darker than you'd like. if it's a skating photo, the ice will not be white (because making the ice white makes the skater's skin and costume too dark). There are lots of technical reasons why this happens. You don't need to understand why though; you just need to know how to correct it.

Automatic correction

Every picture editor has a way to make sweeping changes to the image in order to “improve” it. The advantage of these commands is that they work at least 90% of the time and you don't have to know anything about how the algorithm works to use them. The disadvantage is that some of the time they make the image worse and then what do you do? Also, they are “destructive” commands in that they actually change the pixels in the image and you can't go back a few days later and undo them.

However, they are a good starting place until you are ready to learn about more sophisticated methods.

Sharpening

You may notice that your image is a bit “soft”. This is on purpose. If sharpening is applied in the camera, you can't get rid of it later if it's too much. The ideal amount varies from image to image so most professionals use as little as possible in the camera and apply the exact amount they want when they prep the image for printing.

Because of how sharpening works, you should always perform this command last, right before down-sizing. If you do it earlier, you will increase the “noise” and the “artifacts” in your image.

Not all picture editors have a sharpening command. Some perform sharpening as part of their auto-enhance features.

Down-resing or Down-sizing

Once your image looks as good as it can, you may need to downsize it. Downsizing just means making it smaller. If you've cropped it, you've already made it have less pixels by throwing the ones on the edges away. For most screen uses, you probably still have too many though.

If you are sending your image via email, using it as a wallpaper or uploading it to your web site, you need to down-size it. For email and web sites, your image shouldn't be bigger than 600 on any side. For wallpaper, use a size that fills your computer monitor.

If you are uploading it to a photo sharing site, you don't need to down-size but the bigger it is, the longer it will take to upload it. If you are using it for a screen saver, you'll get better results the bigger your image is.

Saving a copy

Once you are done playing with your image, be sure to save it. It is better to save a copy so that if you decide later you don't like how you've cropped or enhanced or down-sized the image, you can go back to the original and change it.

Now let's try these commands on an actual image using either Photoshop Elements or iPhoto.