131 CHAPTER History and Actions IN THIS CHAPTER Understanding the non- destructive nature of Photoshop Using the History panel to manipulate past adjustments Using the history of edits to paint out changes Using Photoshop’s built-in action to save time Creating custom actions E diting images in Photoshop is done by applying a series of adjust- ments to modify the original pixels in the image. Each adjustment builds on the others until you achieve the desired results. Photoshop provides two powerful features that allow you to be more productive by uti- lizing and manipulating the sets of adjustments made to images. The history feature tracks each change to the individual image. This allows you to have a record of each state of the image during editing. Photoshop provides several highly useful tools that allow you to make dynamic adjust- ments to the image by manipulating the history states. These tools also allow you to play around with different techniques because you can quickly revert back to previous states or remove adjustments that do not work well. The actions feature allows you to bundle a set of adjustments as an individ- ual action. You can save actions to a file and then use them in other images. This feature saves lots of time when you are performing similar adjustments to images. Photoshop: The Non-Destructive Application One of the most powerful features of Photoshop is the ability to make numerous edits to images and see the effects of those edits without destroy- ing the underlying pixel data or previous edits. Many of the edits done to images in Photoshop are the result of a series of adjustments using a variety of tools. Each adjustment builds on another until the end result is reached. 09_584743-ch05.indd 13109_584743-ch05.indd 131 5/3/10 10:20 AM5/3/10 10:20 AM Part I: Getting Started with Adobe Photoshop CS5 132 Unfortunately, it is not an exact science, and you have to try different adjustments until you find a combination that culminates in the desired outcome. The non-destructive nature of Photoshop allows you to freely play around with the edits, tweaking them until they are just right without the fear of ruining previous edits or the original pixels in the image. In fact, you can even remove a single adjustment that was made early on without affecting the original pixels or the subsequent adjustments. To help understand the value of non-destructive editing, think about editing an image for hours and realizing that one of the first edits you had made was a bad decision. If you could not undo that edit, the hours of work would be wasted. The following is a list of the major non-destructive features/tools available in Photoshop: l History: The History panel, discussed later in this chapter, provides a means of quickly viewing each of the adjustment that have been made to the image. The History panel also provides a means of creating snapshots that you can easily revert back to and removing individual edits from the history. l Dialog boxes: Most of the dialog boxes in Photoshop allow you to use the key sequence Ctrl/Ô+Z sequence to undo the last adjustment you made to a field. This feature is very useful if you make a change to a value that you do not like but cannot remember what the original value was. This feature undoes only the last change made. To undo other changes, hold down the Alt key and the Cancel button turns into a Reset button. When you click the Reset button, the values of all fields in the dialog box revert to the original values from when the dialog box was last opened. l Layers: Using adjustment layers, discussed in Chapter 10, you can make adjustments to the image without affecting the actual image itself. The adjustment layers contain adjust- ment data that affects how the image looks when they are applied. Layers are very useful because they can be removed, reordered, and even moved from one document to another in Photoshop. l Layer Comps: The Layer Comps panel is similar to the History panel, but it contains the changes made to each layer. Using the Layers Comp panel, you can easily create multiple versions of the edited image, each with its own set of changes. This makes tracking multi- ple changes to the image easy. l Masks: Creating masks, discussed in Chapter 10, allows you to create a protective shield for an area in the document that protects it from adjustments made. One of the major advantages to masks is that they can be altered at any time, and the alterations are auto- matically updated in the results because they actually sit between the adjustment layer and the layers below. l Alpha channels: The alpha channel, discussed in Chapter11, allows you to add informa- tion that can be applied to areas of the image without actually affecting the other channels. For example, you can add transparency information to an RGB image without affecting the normal pixels in the image. 09_584743-ch05.indd 13209_584743-ch05.indd 132 5/3/10 10:20 AM5/3/10 10:20 AM Chapter 5: History and Actions 133 l Smart objects: Smart objects are a useful feature of Photoshop that provide powerful, yet non-destructive adjustments to images. Using smart objects, you can combine a series of one or more layers, documents, and so on into a single combined object. Then you can apply filters and make other adjustments to the object without actually changing the con- tents. You can change the contents of the original object at any time, and the adjustments apply only to the updated object. This allows you to create a base source image and quickly try different edits without the worry of damaging the work done to make the source image or the original pixels. l Crops: Photoshop allows you to crop images in a non-destructive manner. When you start to crop an image, as discussed in Chapter 3, two options appear in the Options menu: Hide and Delete. If you select Delete, the pixels outside the crop box are thrown away and you work only with the remaining pixels. If you select Hide, the pixels outside the crop box are masked, and although you see the pixel inside the crop box, only the pixels outside the crop box are still present in the image. To restore the cropped pixels, select Image ➪ Reveal all. The canvas expands to the origin size, and any of the layer adjustment applied to the image is applied to the restored pixels. Note The Hide and Delete options in the crop tool menu are available only if you are cropping a layer that does not have the pixels locked. For more information about layers and layer locking, see Chapter 10. n l Revert: At any point while you are editing an image, you can revert to the original state of the file when it was opened or last saved by selecting File ➪ Revert or pressing the F12 key. This should be used only as a last resort. All the changes you have made to the image are lost. However, this option saves you the time of closing the image without saving the changes and reopening it. Using the History Panel The History panel can be one of your best friends in Photoshop because it has the ability to save you hours of lost work. When you are editing images in Photoshop, you are really working from one change to another. These changes are tied together and build on one another. The purpose of the History panel is to track and manage each adjustment you make to the image. The History panel is designed to give you much more flexibility and control than that traditional undo/redo functionality. Using the History panel, you can go undo and even modify one, some, or all of the changes you have made to an image. Note Photoshop allows you to log some of the history information as either metadata in the file or as a separate file. The history logging feature is set from the General panel in the Preferences dialog box as discussed in Chapter 2. n 09_584743-ch05.indd 13309_584743-ch05.indd 133 5/3/10 10:20 AM5/3/10 10:20 AM Part I: Getting Started with Adobe Photoshop CS5 134 The following sections discuss the History panel and how to get the most out of it. They also cover using the Eraser, History Brush, Art History Brush, and selections to roll back and modify individ- ual edits. Understanding the History panel You load the History panel by selecting Window ➪ History from the main menu in Photoshop. The History panel, shown in Figure 5.1, keeps track of a list of the states of the image after each edit is applied. This allows you to quickly go back in time to the state of your document after any of the edits were made. The following sections discuss configuring and using the History panel to make adjustments to your images. FIGURE 5.1 The History panel keeps track of the state of the image after each change is made. Configuring the History panel The History panel can be configured by setting the options in the History panel menu and by set- ting the preferences for history in the general Photoshop Preferences. To configure options from the History panel, select History Options from the History panel menu (refer to Figure 5.1) to bring up the History Options dialog box, shown in Figure 5.2. Using the History Options dialog box, you can configure the following options: l Automatically Create First Snapshot: This automatically creates a snapshot of the origi- nal document when it is loaded into Photoshop. This is a useful feature that allows you to always have an original snapshot to use with the history tools; however, if you know that you do not need to use the history, then turning off this option reduces some processing overhead and memory. l Automatically Create New Snapshot when Saving: This automatically creates a snap- shot every time you save the file in Photoshop. This can be a useful feature; however, it also can be a problem if you have the tendency to save after every little change you make. You may end up with a huge list that really isn’t meaningful. If you use this feature, make sure you are careful about when you save. 09_584743-ch05.indd 13409_584743-ch05.indd 134 5/3/10 10:20 AM5/3/10 10:20 AM Chapter 5: History and Actions 135 l Allow Non-Linear History: Typically, the edits to a document are built on top of each other in a linear fashion. The problem with the linear method is that if you delete one state in the history list, then all the subsequent states also are deleted. When the Allow Non-Linear History option is selected, the history states become disconnected and you can delete one of the states in the middle without deleting the subsequent changes. Note Some of the changes you make to a document are very tightly connected. You should be very careful when using the Allow Non-Linear History option so you do not delete a state on which another state is depending. n l Show New Snapshot Dialog Box by Default: This specifies whether to show the New Snapshot dialog box when creating snapshots. If this option is disabled, the New Snapshot dialog box is not displayed unless you select New Snapshot from the History panel menu. Disabling this option can speed up creating snapshots using the button on the History panel if you do not need to specify a name or source. l Make Layer Visibility Changes Undoable: If this option is not selected, which is the default, then turning layer visibility on and off is not recorded in the history. When this option is selected, turning a layer visibility on or off is recorded in the history and you can undo it using the history tools. FIGURE 5.2 Setting options for the History panel By default, Photoshop keeps a record of at most 20 history states. Each history state takes up mem- ory and requires extra computer processing by Photoshop. For the most part, 20 history states is enough to work from; however, if you are working on an image that requires lots of different edits, you may need to increase the number of history states that are recorded so you can revert or adjust some of the corrections that you are performing. The maximum number of history states is specified in the general preferences of Photoshop. To increase the number of history states that Photoshop keeps available, select Edit ➪ Preferences ➪ General from the main menu in Photoshop (or use the Ctrl/Ô+K shortcut) to launch the prefer- ences. Then select the Performance option and change the value of the History States field in the History & Cache pane. 09_584743-ch05.indd 13509_584743-ch05.indd 135 5/3/10 10:20 AM5/3/10 10:20 AM Part I: Getting Started with Adobe Photoshop CS5 136 Navigating through history states Navigating through the different history states can be done either directly using the History panel or by using keyboard shortcuts. The most common method is to open the History panel, scroll through the history, and select the history state you want to view. When you select a history state, the image window changes back to that state. A sometimes faster option is to use the Ctrl/Ô+Alt/ %+Z keyboard shortcut to navigate backward through history and Ctrl/Ô+Shift/ %+Z keyboard shortcut to navigate forward through history. If you need to go back only a few adjustments to see how the image looked, then this option is by far the fastest and easiest; however, you cannot undo any of the history edits. Tip If you select a snapshot in the History pane, then you can use the Ctrl/Ô+Alt/%+Z keyboard shortcut to navi- gate backward through the snapshots and the Ctrl/Ô+Shift/%+Z keyboard shortcut to navigate forward through the snapshots. n Using snapshots A very useful feature of the History panel is the ability to create snapshots of the image based on a spe- cific state. The snapshot data remains, even if the history data is deleted. This feature provides a very versatile way to make different adjustments to an image and quickly compare between the adjustments. To create a snapshot, click the Create Snapshot button at the bottom of the History panel or select New Snapshot from the History panel menu to bring up the New Snapshot dialog box, as shown in Figure 5.3. Name the snapshot, and select the snapshot source. The snapshot can be taken from the full document, the current layer, or all layers merged. When you click OK, the snapshot appears in the snapshots list at the top of the History. FIGURE 5.3 Creating a snapshot of a history state adds a state that you can go back to at any time. 09_584743-ch05.indd 13609_584743-ch05.indd 136 5/3/10 10:20 AM5/3/10 10:20 AM Chapter 5: History and Actions 137 The snapshots can be treated very much like the history states. You can delete them and even use the History Brush tool on them. Creating documents Another useful feature of the History panel is the ability to quickly turn a history state into a sepa- rate document. This feature is useful if you are editing an image and want to send someone multi- ple versions for her approval. You can make the full edit of the document and then use the History panel to create documents based on the states that you think might meet expectations. To create a document using the History panel, select the state or snapshot to create a document from and then click the Create New Document from Current State button or select New Document from the History panel menu. A new document with the image data from the selected state or snapshot is loaded in Photoshop. The name of the new document is the name of the state or snapshot. Deleting history Clearing the history can be done in a couple of ways. You can select a history state and click the trash can in the History panel or select Delete from the History panel menu. Caution If the Allow Non-Linear History option is selected for the History panel, only the state that was selected is deleted. However, if the Allow Non-Linear History option is not selected, which is the default, then all subse- quent history states are deleted as well. Make sure you know which option is selected before you delete a large amount of history that you need. n You also can clear out all the history in the History panel by selecting Clear History from the History panel menu. This removes all history states. The Clear History option works only on his- tory states; snapshots remain after clearing the history. Painting from history A powerful feature of the History panel is the ability to select a history state and paint or erase directly from that history state or snapshot. This allows you to paint through the changes that have been made until you get down to the selected history state. If you consider the number of brush styles and transparency options available when painting, painting from history opens a variety of possibilities. To enable painting from the History feature, you need to click the box beside the desired state or snapshot in the History panel. The box changes to the History Brush icon, as shown in Figure 5.4. Photoshop uses that state as the base level when painting from history. 09_584743-ch05.indd 13709_584743-ch05.indd 137 5/3/10 10:20 AM5/3/10 10:20 AM . History panel By default, Photoshop keeps a record of at most 20 history states. Each history state takes up mem- ory and requires extra computer processing by Photoshop. For the most part, 20 history. 09_584743-ch05.indd 13109_584743-ch05.indd 131 5/3/10 10:20 AM5/3/10 10:20 AM Part I: Getting Started with Adobe Photoshop CS5 132 Unfortunately, it is not an exact science, and you have to try different. n 09_584743-ch05.indd 13309_584743-ch05.indd 133 5/3/10 10:20 AM5/3/10 10:20 AM Part I: Getting Started with Adobe Photoshop CS5 134 The following sections discuss the History panel and how to get the