PART III Image Editing Basic Editing with Photoshop Elements and iPhoto .113 Editing with Selection Tools .133 Advanced Selection Tools .151 The Importance of Selections .173 The Importance of Filters .191 The Importance of Brightness/Contrast .205 The Importance of Levels and Curves .219 The Importance of Layers and Masks .235 The Importance of Channels .255 In this chapter • Finding an Image on Your Computer • Editing with Photoshop Elements 9 • Resizing an Image in Photoshop Elements • Editing with iPhoto • Working with the Print Dialog Box in iPhoto • Resizing an Image in iPhoto Basic Editing with Photoshop Elements and iPhoto This chapter introduces two common, easy-to-learn image editing appli- cations for today’s new digital photographers: Adobe’s Photoshop Elements 2 and Apple’s iPhoto. Elements is much more powerful than iPhoto, but the latter is much better at organizing images on your com- puter. Both are excellent programs for importing, storyboarding, organ- izing, and printing your images. You don’t need Photoshop to manage your images unless you plan to make a career as a photographer, writer, Web developer, or graphic artist.
As the industry standard, Photoshop includes numerous features that you will never need, such as offset printing and registration tools, Web development and animated GIF tools, and color profiles and modes such as CMYK. 114 ABSOLUTE BEGINNER’S GUIDE TO DIGITAL PHOTOGRAPHY Finding an Image on Your Computer Elements and iPhoto include file browsers, which provide a directory tree of your computer’s innards. These browsers provide a fast, easy way to find images on your computer. Not sure where a picture is located? Open the file browser and start poking around.
In Photoshop Elements, choose Window, File Browser (see Figure 9. The browser provides thumbnails of your images and includes file information.1 The file browser in Elements enables you to find an image quickly. The file browser in Elements isn’t really meant for top-to-bottom image manage- ment. Rather, it provides a quick thumbnail image before opening and enables you to rotate images.
For more thorough file management, you need something like Adobe Album, which is a chronological view of all the images on your computer (see Figure 9. Album provides a much more manageable interface. For Macintosh users, one applica- tion—iPhoto—provides features of Elements and Album. Unlike Photoshop Elements’ browser, iPhoto’s image browser dominates the desktop.
This browser is more of an in-your-face file location tool (see Figure 9. iPhoto’s browser is so powerful that professional photographers use it to organize their clients’ photo shoots. CHAPTER 9 BASIC EDITING WITH PHOTOSHOP ELEMENTS AND iPHOTO 115 FIGURE 9.2 Adobe Album, an optional image man- ager, might come in handy if you have problems find- ing files on your computer.3 iPhoto’s browser can be used to organize your entire photo collection. First let’s explore Photoshop Elements, which is available for the Mac and Windows.
116 ABSOLUTE BEGINNER’S GUIDE TO DIGITAL PHOTOGRAPHY Editing with Photoshop Elements Photoshop Elements is available for Mac and PC computers and includes features designed specifically for amateur photographers.1 highlights several fea- tures found only in Photoshop Elements by comparing it with the industry-standard Photoshop, the most powerful image editor available for non-Unix systems.1 Features Present in Photoshop CS Versus Photoshop Elements 2 In Photoshop CS, But Not In Photoshop Elements 2, in Photoshop Elements 2 But Not in Photoshop CS Paths Auto import of digital camera images Actions Palette and Recordable Actions Auto conversion of photos for the Web and email distribution CYMK Support Quick Fix window, Adjust Lighting, and Auto Color Correction Channels, Curves, and Guides Better menu bar and simplified toolbar Masking Palette Well & PhotoMerge, a panoramic stitch- ing program Editable Vector Shapes Visual representation of filters and effects Photoshop CS retail price: $649 Photoshop Elements retail Price: $99 Many of these features might sound like marketing-speak at the moment, but stick with this chapter and you’ll learn the purpose of each. The bottom line is that for the price, Photoshop Elements is pretty powerful! Printing Resolution One of the most confusing parts of digital photography to a beginner is printing res- olution. The act of scanning in a picture or taking a picture with a digital camera at one resolution and printing at another causes endless headaches for most amateurs. Fortunately, today’s entry-level digital imaging software—Elements and iPhoto— makes this process easier than ever.
Resizing an Image Step by Step If you use an image more than once, you’ll probably need to change its size. In digi- tal imaging, changing the dimensions of an image is called resizing. In Adobe Photoshop Elements 2.0, resizing is performed via the Image, Resize, Image Size command. CHAPTER 9 BASIC EDITING WITH PHOTOSHOP ELEMENTS AND iPHOTO 117 The Image Size dialog box offers two very different ways to resize the image, depend- ing on whether the Resample Image check box is checked.
This check box causes the image to change dramatically through a process called interpolation. Interpolation is a mathematical method that increases image resolution artificially. If the Resample Image check box is not checked, changing the Width, Height, or Resolution fields does not really change the file onscreen. Changes will influence how the image prints, but the file will not actually change.
Any modification to these Image Size fields merely tells the printer to print the image larger or smaller. If you only want to change the print size, uncheck the Resample Image check box. If Resample Image is checked and then you change the Width, Height, or Resolution, the file will change in size, resolution, and quality. When Resample Image is checked (see Figure 9.4), Elements changes the number of pixels in the image.
Resample Image fundamentally and permanently changes the image; the computer increases or decreases the number of pixels in the image, data is usually lost, and the file size is changed.4 Resample Image perma- nently alters the image informa- tion. Only use this when you are forced to resize an image. The following steps explain how to use the Image Size dialog box to convert digital photos and scans to a resolution that will produce the best photos. If you need to resample an image, make sure you modify a copy of the original to keep any mis- takes from ruining your original image: 1.
Open an image in Elements through the file browser (Window, File Browser) or through the File menu (File, Open). Before you do anything, choose File, Save As and save the file with a new name. With the image onscreen, choose Image, Resize, Image Size. When the Image Size dialog box appears, uncheck the Resample Image check box (see Figure 9.
118 ABSOLUTE BEGINNER’S GUIDE TO DIGITAL PHOTOGRAPHY FIGURE 9.5 Uncheck Resample Image to pro- tect the file. Change the printing size of the image by typing a number in the Width, Height, or Resolution (pixels per inch) field. A change to any one of these fields will update the values in the other fields. For example, if the current print width is 15 inches and you want a 10-inch-wide print, type 10 in the Width field.
The Resolution value is helpful, as it tells you how many pixels per inch will appear in the print, so you can estimate how sharp it will look. Most color inkjet printers are very happy printing images at 150–300 pixels per inch (ppi). If you enter a number in this range in the Resolution box, the image will print well on the printer. The following section continues with this exercise after explaining the purpose of resampling.
Resampling an Image Sometimes you must change the number of pixels in an image by resampling. This often happens when you need to reduce (downsample) a large image for a Web site, or enlarge (upsample) a low-res image for a large-format printer. For these situations, you must resample the image. An image that begins its life as a print 2,400×1,600 pixels in resolution must be made much smaller to be viewed on the Web, anywhere from 90×60 to 800×600.
Resampling down is usually not a problem if there is more information than you need (see Figure 9. Let Elements use fancy math to remove this data properly. CHAPTER 9 BASIC EDITING WITH PHOTOSHOP ELEMENTS AND iPHOTO 119 FIGURE 9.6 Downsampling is usually fine. Use Resample Image to down- sample when necessary.
Rescan or Resample a Photo For photos that weren’t scanned in at the correct resolution, should you resample or scan again? If you need the image to be larger that what you currently have, con- sider scanning the image again at a higher resolution instead of resizing it (see Figure 9. A rescanned image will have better quality than one you make larger by resampling.7 Rescan rather than resample if you need a larger size. 120 ABSOLUTE BEGINNER’S GUIDE TO DIGITAL PHOTOGRAPHY It’s usually best to scan photos and negatives at the highest resolution possible, then downsample later. There is a limit to this, however: Scans of photos at resolutions above 2400 samples per inch usually bring out the photo grain, which begins to degrade the scan.
Resampling 101 Resampling an image permanently alters it. Some of its data is discarded when you downsample, resulting in an image that is usually not as good as the original. That being said, if you really have to resample, follow these steps: 1. Open the problem image and save it with a new name.
With the image open in Photoshop Elements, choose Image, Resize, Image Size. Check the Resample Image box if it is not already selected. With this box checked, you can change the number of pixels in the image. Check the Constrain Proportions box.
When this box has a check, it keeps the shape of the image constant. Whenever you make a change to the width or height, Elements automatically adjusts the other dimension. Choose Bicubic from the Resample Image pop-up menu if it is not already selected (see Figure 9. The Bicubic algorithm resizes the image with the greatest amount of image quality possible.
Use the faster but lower-quality methods—Nearest Neighbor and Bilinear—only if Bicubic resampling takes too long with your computer.8 Bicubic is the highest-quality algorithm for resizing an image. Change the number of pixels. There are three ways to do this: ■ Type the number of pixels you want in the Pixel Dimensions Width or Height fields. The print size will also change.
CHAPTER 9 BASIC EDITING WITH PHOTOSHOP ELEMENTS AND iPHOTO 121 ■ Type values for the Document Size Width or Height. The number of pix- els will automatically change to match the new document (print) size. This is recommended if your goal is to print the image on a specific size piece of paper, such as 8 1/2×11 or 11×17. ■ Type a value in the Resolution (pixels per inch) field.
The number of pixels will automatically change to match the new resolution. The print size will not change. When you finish, click OK and print the image. Modifying an Image in Elements Many images need to be rotated.
Film and prints can easily be misaligned in a scan- ner, and often cameras are not held level. As a result, architectural elements or the horizon might appear tilted. To correct this, you can rotate the entire image. Perspective Correction in Elements You can change the shape of images to correct errors in perspective or for creative purposes.
Ordinary 35mm camera lenses cannot correct for perspective. When a camera is pointed up at a tall building, the picture it takes will show the building’s sides converging toward the top of the image. Perspective controls in software can correct this; the sides of the building will appear parallel after editing.9 was taken with an ordinary wide-angle lens pointed upward. The vertical lines of the building should appear parallel, but they converge because of distortion.9 Correcting per- spective on a building photo- graphed from ground level.
Doesn’t look right, does it?