Photoshop can open and save images in many file formats, which are different ways of organizing the information in a file so that it can be used by other applications, printed, or placed on a web page. Each file format is like a different language. Every program that uses image files can speak one or more languages, but not all programs speak the same set of languages. So the format in which you save each image file depends on what programs will need to open or display that image. For example, web browsers can usually open JPEG, GIF, and PNG files, so a web image should be saved in one of those formats. Page-layout programs, on the other hand, are more likely to understand TIFF and EPS files, so those formats are the ones you should use when you’re saving a picture to be used in a newsletter or other document.

File formats are usually indicated by three-letter filename extensions, such as .doc for a word processing document and .bmp for a bitmapped graphic. Because you can hide the filename extensions in both Windows and Mac OS X, you might not see extensions. But rest assured, they’re there.

Most file formats can accommodate some, but not all, of Photoshop’s special features. For example, if your image uses layers (we talk more about layers in Hour 11, “Creating Layered Images”), saving it in JPEG or EPS format flattens the layers so that you can no longer edit them separately. To preserve layers, you need to save in a format that can accommodate them. Your best choice is Photoshop’s native format, which can accommodate all of the program’s special features. The filename extension for Photoshop format is .psd, which stands for “Photoshop document.” Because other programs in which you want to use your pictures might not be capable of reading Photoshop native format, you need to save a copy of a completed image in a compatible format when you’re ready to use the picture outside Photoshop.

A second native file format, called Large Document Format (.psb), was introduced in Photoshop CS. It’s meant to handle very large files—more than 2GB in size; think of it as Photoshop Big. This format was developed to let you work with and save multiple layers in a very large document. Anything you save as a .psb file can be opened only in Photoshop CS or later. You can make the format available by choosing Preferences, File Handling and turning on PSB support in the dialog box. If you share files with users of versions of Photoshop prior to Photoshop CS, leave it off.

Photoshop can read and write dozens of graphics formats; here’s a rundown on the most commonly used formats in that group.

These file formats, and some less common ones, such as Targa and Scitex CT, are available in the Save dialog box—choose File, Save, or File, Save As. Just look for the Format pop-up menu. Figure 2.1 shows the Save As dialog box with the formats available.

Figure 2.1. Photoshop CS4 can save your work in any of these formats.

If you work on a Mac and need to share files with non-Mac users—or if you just like to stay on the safe side—choose Preferences, File Handling. In the dialog box, click the check boxes to make sure that Photoshop automatically adds a filename extension to each file you save and to keep it in lower case (as required by some older software).

Opening Files

Opening a file in Photoshop is as easy as it is in any other application. You can open as many images as your computer’s memory (RAM) can hold, which is just one reason you can never have too much RAM. If a file is of the proper type (a file format that Photoshop recognizes), all you have to do is double-click it to open it and launch Photoshop as well, if it’s not already running. (If Photoshop is already open, you can either double-click an image file’s icon or choose File, Open in Photoshop.) You can also drag and drop a compatible file onto the Photoshop CS4 icon to open that file.

When you open files using the Open command, Photoshop’s Open dialog (see Figure 2.2) displays all the files that have formats it can open. As you can see, Photoshop also displays a thumbnail of the selected image. To make sure that previews are included in the image files you create, choose Preferences, File Handling, and then choose Always Save from the Image Previews pop-up menu in the dialog.

Figure 2.2. Photoshop’s Open dialog includes a preview of the selected image.

A thumbnail or thumbnail sketch is an artist’s term for a small version of a picture, so called because it’s often no bigger than a thumbnail. A thumbnail version of an image can be stored in a file along with the full-size image so that some programs, including the Mac OS and Windows, can see the image file’s contents without having to open it.

Open a File

As you’ve seen, Photoshop supports most graphics formats. You must have some image files somewhere on your hard drive, so let’s find one and open it.

1. Choose File, Open or press Command-O (Mac) or Ctrl+O (Windows) to display the Open dialog box.

2. Use the dialog box to locate the file you want to work on. Try looking in the Pictures or My Pictures folder within your Documents folder.

3. Double-click the file’s name, or click it once and then click the Open button.

Browsing for Images

If you have only a few graphics files, and if you’re really good at keeping things organized, finding the document you’re looking for isn’t difficult. However, if you’re like me, your files are all over the place, and they’re often named with the apparently random numbers the camera assigns. That’s why Photoshop’s Bridge (see Figure 2.3) remains one of the program’s most useful features. It helps you preview all your images, sort them, search them, and even read their metadata—information about the files themselves. You can scroll through the information in Bridge’s Metadata tab to determine what lens and shutter settings the camera used, whether the exposure required a flash, and the precise minute and second the picture was taken—virtually everything you need to know except where it was shot. Actually, some special-purpose digital cameras with GPS connections can tell you where each picture was taken, and, of course, many camera phones include built-in GPS capabilities.

Figure 2.3. You can drag the dividers to change the size of any of the frames that make up the Bridge window.

Navigate Within Bridge

To open Bridge, choose File, Browse in Bridge, and then follow these steps to take it for a spin:

1. Click a tab at the upper-left (Favorites or Folders) and navigate through the folder hierarchy to locate the folder you want. Whenever you select a folder containing image files, you’ll see all its images displayed in the Content tab, as if on a slide viewer. If this is the first time that you’ve viewed this folder’s contents in Bridge, it might take few minutes to display all the thumbnails, but don’t let that put you off; the display will be lightning-fast the next time you look at this folder in Bridge.

2. If folders are nested inside the one you originally opened, you’ll see them as folder icons in the Content tab. Double-click a nested folder to see the images it contains.

3. Scroll through the folders and the images within them until you find the one you want. Double-click the thumbnail image in the Content tab or the preview in the Preview tab to open the image file in Photoshop. The Folders tab, in the upper-left corner of the Bridge window, shows the location of the file you’re opening.

4. If the folder you’re looking at contains a lot of files, you can hide the ones that don’t match using the Filter tab. Click next to the criteria you want to use—such as JPEG File and a creation date—to hide all files that don’t meet those criteria. Then you can choose the file you’re looking for from a much smaller number of images.

5. To keep track of groups of related photos, you can create collections in the Collections tab. Click New Collection to add a collection, and assign it a name. Drag pictures over the new collection to include them; then click the collection to view only the photos it contains. You can also create smart collections that add new images automatically based on metadata and keywords; we look at using these in the next section.

You can configure Bridge’s setup to suit your needs. Bridge comes with several predesigned arrangements, including Metadata, for viewing very small thumbnails alongside lots of file info, and Output, for previewing how images will look when output in various ways. Click an option at the top of the Bridge window to choose a different view (see Figure 2.4).

Figure 2.4. Bridge is highly customizable; you can set it to display just the information that interests you.

Creating and Using Metadata

As I mentioned earlier in this hour, metadata is information about an image that’s included in the file along with the actual picture. To get an idea of what sort of data can show up in a file’s metadata, open Bridge and take a look at the Metadata tab (see Figure 2.5). Bridge divides metadata into several categories:

• File Properties—. These bits of info qualify as an image’s vital statistics, and they’re not editable in Bridge. They include the file’s color mode, size, resolution, name, creation date, and modification date, for starters.

• IPTC Core—. Established by the International Press Telecommunications Council (IPTC), this data set includes all kinds of things that press organizations might need to know about an image, such as who created it, its subject, where it was taken, and what usage rights apply. You can edit any of these fields.

• Camera Data (EXIF)—. The Exchangeable Image File Format is a standard for storing information within image files, especially JPEG files. Most digital cameras use EXIF to store metadata about the images they generate. This includes the camera’s focal length and aperture value, as well as whether a flash was used. This data, if it’s available, can’t be edited in Bridge.

• Audio—. You can add any of several types of data in the Audio category, mostly applicable to music, such as artist, genre, and instrument. Of course, you’re unlikely to apply any of this information to a Photoshop file, but Bridge functions as a media organizer for all the programs in Adobe’s Creative Suite, including Flash and Premiere.

• Video—. Fields in this category include Scene and DateShot, which are the sort of information you’d want to keep track of for snippets of video footage.

• DICOM—. The Digital Imaging and Communications in Medicine standard enables medical professionals to track metadata in medical images. It includes fields such as Patient Name, Patient Sex, Referring Physician, and Study Description.

• Mobile SWF—. This kind of information is stored in Flash (SWF) files; again, Photoshop users are unlikely to use this metadata, but it’s great for Flash designers. Fields include Content Type and Forward Lock (which specifies whether the file can be transferred to another device).

Figure 2.5. Metadata is automatically stored with each image, and you can add more data to it, if you want.

To add your own metadata to an image, just click in a text field and enter the text you want to include. Pencil icons indicate the fields you can modify.

Smart collections can be based on any combination of metadata values, both data you’ve inserted yourself and data that was already part of the file (such as its name). For example, you could make a collection that includes all JPEG files created in Italy during 2008 using a flash, to keep track of your vacation photos. You can also create smart collections based on keywords, which you can think of as your own custom metadata. Bridge’s Keywords tab, located alongside its Metadata tab (see Figure 2.6), enables you to create keywords (click New Keyword at the bottom of the tab) and assign them to a selected image or group of images by checking the box next to each keyword.

Figure 2.6. If you create many keywords, you’ll probably find it useful to maintain a list of them in a text file.

Note: Consistency Is Key

Using the Import and Export commands in the pop-up menu at the upper-right corner of the Keywords tab, you can create sets of keywords to exchange with other users. That’s a great way to ensure that all the people you might exchange images with are using a consistent set of keywords to tag those pictures.

Importing a File

Photoshop’s Import command (choose File, Import) lets you open files that have been saved in unusual formats or that aren’t on your hard drive. Typically, these include images created with your scanner or digital camera, and special image types such as individual frames of video.

Importing from Digital Cameras

Photoshop can import pictures directly from most digital cameras. The easiest way to do this is to use Bridge; after you’ve plugged in your camera, open Bridge and choose File, Get Photos from Camera, or click the Get Photos from Camera button in the toolbar. In the resulting Photo Downloader dialog box (see Figure 2.7), you can choose your camera and a location for the photos; then click Get Photos. Photoshop copies the photos into a new folder on your computer’s hard drive. If you want to change the default folder name or filenames for the imported photos, choose new options in the Import Settings section of the dialog.

Figure 2.7. The Photo Downloader is primarily used to specify where you want your photos stored and how you want them named.

Bridge can recognize most cameras, but if it doesn’t see yours, don’t worry. Most cameras come with a Photoshop plug-in that you can drop into the Plug-ins folder. After you’ve quit Photoshop and restarted the program, a new command appears in the Import submenu, named to match your camera. When you choose this command, you’ll see whatever interface the camera designer has created for importing photos. To work on the camera’s pictures in Photoshop, you must import them using this plug-in and then open them from within Photoshop. Check your camera’s instruction manual to learn how to use the particular plug-in for your camera.

Scanning Pictures

Digital cameras generate most digital photos these days. But there are still plenty of times when you’ll need to scan artwork for use in Photoshop, whether it’s because you have only a print of the photo in question or because the art isn’t a photo—perhaps it’s a drawing or some other flat object you need to reproduce. Photoshop doesn’t offer a universal scanning interface analogous to the Photo Downloader, so scanning is handled either by your operating system or via a plug-in supplied by your scanner manufacturer.

This means that what you see when you bring up your scanner interface probably won’t look exactly like Figure 2.8. But the principles are the same:

1. You do a preview scan (sometimes called an overview scan).

2. Then you select the area of the scanner bed that you want to include in the scan. Some scanner software is smart enough to guess at the area you want to scan, but you can usually override the selection if the program guesses wrong.

3. You choose the kind of image you’re scanning—color, grayscale, or black and white. Remember, a black-and-white photo is actually a grayscale image that contains hundreds of shades of gray. You’ll most likely use the black-and-white setting when you’re scanning text or a line drawing, such as a floor plan.

4. You choose an image resolution for the scan, which could involve specifying an actual number or telling your scanner software what you plan to do with the image—print it or just display it on the Web.

5. You can choose a few image adjustments, such as sharpening, to be performed as the scan is made. I prefer to work on the raw image data in Photoshop, but if you’re in a hurry to get some photos up on your website, letting the scanner do the work is a time-saving option.

6. Finally, you click Scan and wait for the new image to open in Photoshop (see Figure 2.9). When it does, you need to save it, choosing a name, location, and format in the Save dialog.

   

   Figure 2.8. This is the Home version of Epson’s Mac scanning software; the plug-in also has Automatic and Professional modes.

   

   Figure 2.9. Scanning an object is much quicker than photographing it and transferring the picture to your computer, and it often results in a better image.

Importing Video Images

You can also turn video frames into layers within a Photoshop image. Choose File, Import, Video Frames to Layers, and navigate to the video file you want to open. In the Import Video to Layers dialog box, use the slider to choose the range of frames to import; then click OK. Photoshop turns each frame into a separate layer that you can view, hide, and edit individually. Turn to Hour 11 to learn how to manipulate layers.

Note: Scanning Outside Photoshop

Your scanner might have come with a scanning program that you like, or you might be a Mac user and prefer to do all your scans using the Image Capture program that comes with Mac OS. Either way, if you’re saving scanned files and then bringing them into Photoshop, be sure to use a format such as TIFF that doesn’t have lossy compression, as JPEG does. Lossy compression removes image data, causing a loss of quality every time you save. Never save files in a lossy format until you’re sure you’re done working with them. You can learn more about compression, both lossy and lossless, in “Making Your Files Smaller,” later in this hour.

Starting a New Image

When you don’t want to start with an existing image, you can have Photoshop create a blank canvas in any size, ready for your artwork. To get started, choose File, New (the first command in Photoshop’s File menu). In the New dialog box (see Figure 2.10), you can enter a name for your new file or leave it untitled for now. Other choices have to be made now, however. The following sections show you how to set up a new file.

Figure 2.10. The New dialog box enables you to create a blank document to your individual specifications.

Note: If Video Really Moves You

Photoshop CS4 Extended adds the capability to work with full-motion video right within Photoshop. If that sounds like something you need to look into, turn to Appendix B, “A Quick Walk on the Extended Side,” to learn more.

Image Size

The simple way to specify an image size is to use the Preset and Size pop-up menus. The Preset pop-up lists several categories: Clipboard, Default Photoshop Size, U.S. Paper, International Paper, Photo, Web, Mobile & Devices, Film & Video, and Custom. After you choose a Preset option, the Size menu becomes available so that you can choose among the sizes in that category. For example, when you choose U.S. Paper from the Preset menu, your Size choices are Letter, Legal, and Tabloid. Photoshop CS4 also includes a wide selection of TV and video formats, including PAL and HDTV screen sizes, as well as sizes customarily used with phones, handheld organizers, and other devices. Of course, you can also specify a custom size for your image—width and height—in pixels, inches, centimeters, points, picas, or columns across. All of these settings are available in pop-up menus (see Figure 2.11).

Figure 2.11. Photoshop offers you standard image sizes for print and electronic images, as well as the option of entering a custom size.

Tip: It’s Magic!

If you’ve copied an image to the Clipboard when you create a new document, the dialog box automatically shows the size of the copied image. If you switch to another size option and then change your mind, choose Clipboard from the Preset pop-up menu to reset the dialog to the size of the image on the Clipboard.

The Default Photoshop Size option in the Size pop-up menu provides you with a 7×5-inch work area, a convenient size for most projects.

Resolution

Resolution refers to the number of pixels per inch (ppi) within an image, which determines the image’s quality. Each pixel is a square of a single color. When we look at an image from a distance or shrink the image to make the pixels smaller, we don’t see squares; our eyes see the picture. As you might imagine, a higher resolution gives you a sharper, more detailed image but results in a larger file that takes longer to open and to transfer online. Most images that you see in print have a resolution ranging from 150 ppi to 300 ppi. Your computer’s monitor, on the other hand, probably displays 72 ppi, which is substantially fewer than 300. Therefore, you always set the resolution for an image depending on how you plan to output the picture—will you print it or will it be only displayed onscreen?

Tip: Plan Ahead...

If you intend to publish your images on the Web, ignore resolution completely. Instead of thinking of an image as “so-many-inches by so-many-inches at 72 ppi,” think of the image as being “this-many-pixels by this-many-pixels.” Consider how much of the web page the image will cover. If, on the other hand, you are printing to a high-quality color inkjet or laser printer, set the resolution to 200 ppi. Use 300 ppi only if you need to create high-quality color prints.

Color Mode and Background Contents

The New dialog also offers you a choice of color modes for the image file you’re creating. We talk a lot more about color modes in Hour 5, “Adjusting Brightness and Color.” For now, stick with RGB (based on primary colors of red, green, and blue)—it offers you the widest range of available colors and is optimal for printing on inkjet printers and displaying onscreen. You also need to decide what color you want the Background layer to be; think of this as the canvas or paper color. You can choose black, white, or any other color, or you can choose to start with a transparent layer and skip the Background layer entirely, which is akin to painting or drawing on a transparency sheet.

The New File

After you click OK in the New dialog box, a new, empty window or tab opens. This is the active window, and the canvas is the large white square within it. You can have more than one window open within Photoshop at the same time, but only one can be the active window. The active window is always in the foreground. This is where you create and edit images. If Open Documents as Tabs is checked in the Interface preferences, multiple windows are grouped together; you switch documents by clicking the appropriate tab.

You can enlarge the window itself by clicking and dragging its lower-right corner. This doesn’t change the size of your image’s canvas, however; it’s just a way to see more of the canvas at one time when you’re zoomed in at a high magnification. If you do want to change the size of the canvas, you can do so by choosing Image, Canvas Size. In the Canvas Size dialog, you can specify a new height and width for the canvas, as shown in Figure 2.12. Click any of the nine squares in the Anchor section to specify the point from which the canvas expands or shrinks.

Figure 2.12. Click a square in the Anchor proxy to position the existing contents of the canvas in the corresponding area of the enlarged canvas.

If you want to enlarge or shrink the canvas by a specific amount of space, you’ll find the Relative check box very useful. Check the Relative box to add or subtract the specified amount to the size of the existing canvas.

Enter a positive value to make the canvas larger and a negative value to make it smaller. Remember, if you want to add a specific measurement on all four sides of your image, you need to double that amount in the Width and Height fields so that the correct amount is added all the way around.

The most important thing to know about saving your work is this: Do it often! Computers can shut down unexpectedly, and software can crash. Occasionally pressing Command-S (Mac) or Ctrl+S (Windows) to save as you go along takes only a couple seconds, and it can prevent the night-mare scenario of having to do your work all over again if disaster strikes.

The first time you save a picture, you’ll see the Save As dialog, shown in Figure 2.13. Give the file a name and choose an appropriate format to save it in from the pop-up menu (check out the “Choosing a Format” section later in this hour for help). Navigate to the folder where you want to save the file, and click Save to save the file.

Figure 2.13. Saving a file in Photoshop

You can find the option to save a copy of your current image in the Save As dialog box—check As a Copy to use it. As with Save As, the As a Copy option lets you save the file with a new name and in a new location. The difference is that, after you use Save As, you’re working in the new file. But if you use As a Copy, you save a copy of the file as it is at that moment, but you’re still working on the original file, not the copy. Saving with As a Copy checked is especially useful for making a backup copy before you try a drastic change, such as reducing color depth or increasing JPEG lossiness, or for saving the file in a different format. Suppose that you create a logo for your business and want to use it in print and on the Web. You’d save it as a TIFF or EPS file to print from, and you’d save a copy as a JPEG or PNG file for your web page. The word copy is automatically added to the filename, but you can delete it if you’re saving the copy in a different format, because the new file’s filename extension will be different from the original’s.

The final Save option, located in the File menu, is Save for Web & Devices. It brings up a gigantic dialog box that contains the settings you need to optimize an image for use on websites or on the small screens of cell phones and handheld organizers. For example, you can see the effects of varying amounts of JPEG compression, so you can choose a setting that balances file size and image quality. You’ll learn about these options in detail in Hour 24.

Photoshop’s History panel and History Brush tool are designed for those of us who don’t get everything right the first time—in other words, pretty much everyone. The History panel keeps a list of every tool you’ve used and every change you’ve made, up to a predetermined number you can set in the History Options panel menu. You can also take “snapshots” of the work in progress and use these as saved stages to which you can revert. Figure 2.14 shows the History panel for a picture that’s had a lot of changes made to it.

Figure 2.14. The History palette logs each change made to the current picture.

You can click any previous step to revert to it if a change to an image doesn’t work out the way you anticipated. The History panel is more useful in some ways than simply being able to choose the Undo command multiple times, because the History panel lets you undo and redo selectively by choosing the step you want to revert to. More important, it enables you to save your work as you do it and still go back and undo. In early versions of Photoshop, and in some other programs, after you save your work, Undo isn’t available. We discuss the uses of the History panel and the History Brush (which lets you undo as much or as little of a change as you want) in greater detail in Hour 8, “Different Ways to Paint.”

Of course, you can always use Command-Z (Mac) or Ctrl+Z (Windows) to toggle the Undo and Redo commands in a single step. For multiple undos, press Command-Option-Z (Mac) or Ctrl+Alt+Z (Windows) repeatedly.

If you’re using Photoshop as part of Adobe Creative Suite, you have access to a great utility called Version Cue that’s integrated into the Open and Save dialog boxes of all the Creative Suite programs. It keeps track of previous versions of files and of alternate versions created during the design process, so you can always locate the version you, or your client, need. Version Cue also enables you to share files with other people in a workgroup, keeping track of who’s working on which file at any given time, and it groups related files so that you have easy access to all the parts of a project.

To turn on Version Cue within Photoshop, go to the File Handling section of the Preferences dialog and check the box labeled Enable Version Cue.

Version Cue organizes files into projects. You assign each file to a project the first time you save it. To be able to do this, Mac users need to make sure they’re using the Adobe Open and Save dialogs. If not, you’ll see a Use Adobe Dialog button in the Open and Save dialogs; click it to see the Adobe dialog, which includes a Favorites area on the left. Click Version Cue in the Favorites column to see your projects, if you have any (see Figure 2.15).

Figure 2.15. With Version Cue, you must assign each file to a project.

When Version Cue is active, you can save different versions of a file by choosing File, Check In as you work. Each time, you’re asked to enter comments about the new version. If you want to return to a previous version at any time, you can do so from the Open dialog box—choose Versions from the Tools pop-up menu in the upper-right corner of the dialog, and you’ll see a list of the versions you’ve saved for that image (see Figure 2.16).

Figure 2.16. The comments entered with each new version enable you to remind yourself or co-workers of what changed with that version.

Photoshop can work with many kinds of image files from many sources. You can open most files by either double-clicking the file or using the Open dialog box, and you can import others using plug-in filters. If you have a digital camera or scanner, it probably came with a Photoshop plug-in that enables you to import pictures directly into Photoshop. Check your owner’s manual or the company’s website.

Logically enough, Photoshop can also save documents in all the formats it can open (except Raw). Different formats have different purposes, and they yield different file sizes. Some are specifically intended for web use, others for printing. Choose a format based on the intended use of the image.

The History palette shows a step-by-step list of everything you’ve done to an open image. You can travel backward or forward through the History list by clicking any step and easily undo or redo your changes, even if you have already saved the document. For an even more powerful “time travel” effect, you can use Version Cue to keep track of multiple versions of each file you work on.