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CHAPTER 20 IMAGE EDITING To access the Levels feature, right-click the image and select Layer . Colors . Levels. This presents a chart of the brightness levels in the photo and lets you set the dark, shadows, and highlight points, as shown in Figure 20-4. Three sliders beneath the chart represent, from left to right, the darkest point, the midtones (shadows), and the highlights within the picture. The first step is to set the dark and light sliders at the left and right of the edges of the chart. This will make sure that the range of brightness from the lightest point to the darkest point is set correctly. The next step is to adjust the middle slider so that it s roughly in the middle of the highest peak within the chart. This will accurately set the midtone point, ensuring an even spread of brightness across the image. Figure 20-4. The Levels function can be used to accurately set the brightness levels across an image. A little artistic license is usually allowed at this stage and, depending on the effect on the photo, moving the midtone slider a little to the left and/or right of the highest peak might produce more acceptable results. However, be aware that the monitor might be showing incorrect brightness/color values. Cropping and Cloning After you ve adjusted the colors, you might want to use the Crop tool (see Table 20-1) to remove any extraneous details outside the focus of the image. For example, in a portrait of someone taken from a distance away, you might choose to crop the photo to show only the person s

308 CHAPTER 20 IMAGE EDITING Figure 20-3. Set the opacity of various layers by clicking and dragging the relevant slider in the Layers dialog box. Making Color Corrections The first step when editing most images is to correct the brightness, contrast, and color saturation. This helps overcome some of the deficiencies that are inherent in digital photographs or scanned-in images. To do this, right-click the image and select Layers . Colors. You ll find a variety of options to let you tweak the image, allowing you a lot of control over the process. For trivial brightness and contrast changes, selecting the Brightness/Contrast menu option will open a dialog box where clicking and dragging the sliders will alter the image. The changes you make will be previewed on the image itself, so you should be able to get things just right. Similarly, the Hue/Saturation option will let you alter the color balance and also the strength of the colors (the saturation) by clicking and dragging sliders. By selecting the color bar options at the top of the window, you can choose individual colors to boost. Clicking the Master button will let you once again alter all colors at the same time. The trouble with clicking and dragging sliders is that it relies on human intuition. This can easily be clouded by a badly calibrated monitor, which might be set too dark or too light. Because of this, The GIMP offers another handy option: Levels.

CHAPTER 20 IMAGE EDITING Figure 20-2. Paths allow for more elaborate and intricate selections, such as those that involve curves. Layers: In The GIMP (along with most other image-editing programs), layers are like transparent sheets of plastic that are placed on top of the image. Anything can be drawn on each individual transparent sheet, and many layers can be overlaid in order to create a complicated image. Layers also let you cut and paste parts of the image between them. It s also possible to apply effects and transformations to a single layer, rather than to the entire image. The Layers dialog box, shown in Figure 20-3, appears by default, but if you closed it earlier, you can open it again by right-clicking the image and selecting Dialogs . Layers. The layers can be reordered by clicking and dragging them in the dialog box. In addition, the blending mode of each layer can be altered. This refers to how it interacts with the layer below it. For example, its opacity can be changed so that it appears semitransparent, thereby showing the contents of the layer beneath.

306 CHAPTER 20 IMAGE EDITING Editing Images with The GIMP After you ve started The GIMP (and assigned it a virtual desktop), you can load an image by selecting File . Open. The browser dialog box offers a preview facility on the right of the window. You will probably need to resize the image window so that it fits within the remainder of the screen. You can then use the Zoom tool (see Table 20-1) to ensure that the image fills the editing window, which will make working with it much easier. You can save any changes you make to an image by right-clicking it and selecting File . Save As. You can also print the image from the same menu. Before you begin editing with The GIMP, you need to be aware of some essential concepts that are vital to understand in order to get the most from the program: Copy, cut, and paste buffers: Unlike Windows programs, The GIMP lets you cut or copy many selections from the image and store them for use later. It refers to these saved selections as buffers, and each must be given a name for future reference. A new buffer is created by selecting an area using any of the selection tools, then right-clicking within the selection area and selecting Edit . Buffer . Copy Named (or Cut Named). Pasting a buffer back is a matter of right-clicking the image and selecting Edit . Buffer . Paste Named. Paths: The GIMP paths are not necessarily the same as selection areas, although it s nearly always possible to convert a selection into a path and vice versa (right-click within the selection or path and look for the relevant option on the Edit menu). In general, the tools used to create a path allow the creation of complex shapes rather than simple geometric shapes, as with the selection tools. You can also be more intricate in your selections, as shown in the example in Figure 20-2. You can save paths for later use. To view the Paths dialog box, right-click the image and select Dialogs . Paths. Tip Getting rid of a selection or path you ve drawn is easy. In the case of a path, simply click on any other tool. This will cause the path to disappear. To get rid of a selection, select any selection tool and quickly click once on the image, being careful not to drag the mouse while doing so.

CHAPTER 20 IMAGE EDITING 305 Table 20-1. The GIMP Image-Editing Tools (Continued) Tool Description of Use Gradient fill This tool will create a gradient fill based on the foreground and background colors by clicking and dragging. Pencil tool This tool lets you draw individual pixels when zoomed in, or hard-edge lines when zoomed out. Simply click and drag to draw freehand, and hold down Shift to draw lines between two points. Brush tool This tool lets you draw on the picture in a variety of brush styles to create artistic effects. A brush can also be created from an image, allowing for greater versatility. Erase tool Rather like the Brush tool in reverse, this tool deletes whatever is underneath the cursor. If layers are being used, the contents of the layer beneath will become visible. Airbrush tool This tool is also rather like the Brush tool, in that it draws on the picture in a variety of styles. However, the density of the color depends on the length of time you press the mouse button. Tap the mouse button, and only a light color will appear. Press and hold the mouse button, and the color will become more saturated. Ink tool This tool is like the Brush tool except that, rather like an ink pen, the faster you draw, the thinner the brush stroke is. Pattern stamp Commonly known as the clone tool, this is a popular image-editing tool. It is able to copy one part of an image to another via drawing with a brush- like tool. The origin point is defined by holding down Ctrl and clicking. Blur/sharpen tool Clicking and drawing on the image will spot blur or sharpen the image, depending on the settings in the tool options area in the lower half of the toolbar. Smudge tool As its name suggests, clicking and drawing with this tool will smudge the image, rather like rubbing a still-wet painting with your finger (except slightly more precise). Burn and dodge tool This tool lets you spot lighten and darken an image by clicking and drawing on the image. The results depend on the settings in the tool options part of the window. Directly beneath the image-editing tool icons, on the right, is an icon that shows the foreground and background colors that will be used when drawing with tools such as the Brush. To define a new color, double-click either the foreground (top) or background (bottom) color box. To the left is the pattern selector, which lets you choose which patterns are used with tools such as the Brush. Beneath these icons, you ll see the various options for the selected tool. By using the buttons at the bottom of the window, you can save the current tool options, load tool options, and delete a previously saved set of tool options. Clicking the button on the bottom right lets you revert to the default settings for the tool currently being used (useful if you tweak too many settings!). Next to the toolbar window is the Layers dialog box. This can be closed for the moment, although you can make it visible again later, if you wish.

304 CHAPTER 20 IMAGE EDITING Table 20-1. The GIMP Image-Editing Tools (Continued) Tool Description of Use Shape selection tool Path creation tool Color picker Zoom tool Measurer Move tool Crop tool Rotate tool Scale tool Shear tool Perspective tool Flip tool Text tool Fill tool Another magical tool, the shape selector lets you create a selection by clicking on various points within an image, with the program joining the points together based on the color differences between the two points. This means that you can select the outline of a car by clicking a few points around the edge of the car and, provided the color of the car is different from the background, The GIMP will work out the color differences and select the car s shape automatically. This tool draws Bezier curves in order to create paths. Paths are akin to selections and can be saved for use later on in the image-editing process. Creating a Bezier curve is not too hard to do: just click and drag to draw a curve. Each extra click you make will define a new curve, which will be joined to the last one. To turn the path into a selection, click the button at the bottom of the toolbar. This lets you see the RGB, HSV, or CMYK values of any color within the image. Simply click the mouse within the image. Click to zoom into the image, right-click to see various zoom options, and hold down the Alt key while clicking to zoom out. This tool measures distances between two points (in pixels) and also angles. Just click and drag to use it. The measurements will appear at the bottom of the image window. Click and drag to move any selection areas within the image, as well as rearrange the positioning of various layers. Click and drag to define an area of the image to be cropped. Anything outside the selection area you create will be discarded. This tool rotates any selections you make and can also rotate entire layers. It opens a dialog box in which you can set the rotation manually. Alternatively, you can simply click and drag the handles behind the dialog box to rotate by hand. Known in some other image editors as transform, this tool lets you resize the selection area or layer. It presents a dialog box where you can enter numeric values, or you can click and drag the handles to resize by hand. This tool lets you transform the image by shearing it. Slant a selection by clicking and dragging the corners of the selection area (if the selection area isn t square, a rectangular grid will be applied to it for the purposes of transformation). This tool lets you transform a selection by clicking and dragging its four corners and independently moving them without affecting the other corners. In this way, a sense of perspective can be emulated. This tool flips a selection or image so that it is reversed on itself, either horizontally (click) or vertically (hold down Ctrl and click). Click on the image to add text. Fill a particular area with solid color, according to the color selected in the color box below.

CHAPTER 20 IMAGE EDITING Figure 20-1. The GIMP s main toolbar window Beneath the menu bar in the main toolbar window are the tools for working with images. Their functions are described in Table 20-1, which lists the tools in order from left to right, starting at the top left. Table 20-1. The GIMP Image-Editing Tools Tool Description of Use Rectangular selection tool Elliptical selection tool Hand-drawn selection tool Contiguous regions selection tool Color region selection tool Click and drag to select a rectangular area within the image. This selected area can then be copied and pasted into a different part of the image or turned into a new layer. Create an oval or circular selection area within the image, which you can then copy and paste. Click and draw with the mouse to create a hand-drawn selection area. Your selection should end where it started. If not, The GIMP will draw a straight line between the start and end of the selection. Known as the magic wand in other image editors, this tool creates a selection area based on the color of the pixels where you click. For example, clicking on a red car hood will select most, if not all of the hood, because it is mostly red. This tool works like the contiguous region selection tool, but will create a selection across the entire image based on the color you select. In other words, selecting a black T-shirt will also select a black signpost elsewhere in the picture if the shades are similar.

302 CHAPTER 20 IMAGE EDITING Introducing The GIMP The GIMP is an extremely powerful image editor that offers the kind of functions usually associated with top-end software like Adobe Photoshop. Although it s not aimed at beginners, those new to image editing can get the most from of it, provided they put in a little work. The program relies on a few unusual concepts within its interface, which can catch many people off guard. The first of these is that each of the windows within the program, such as floating dialog boxes or palettes, gets its own Panel entry. In other words, The GIMP s icon bar, image window, settings window, and so on have their own buttons on the Panel alongside your other programs, as if they were separate programs. Note The GIMP s way of working is referred to as a Single Document Interface, or SDI. It s favored by a handful of programs that run under Linux and seems to be especially popular among programs that let you create things. Because of the way that The Gimp runs, before you start up the program, it s a wise idea to switch to a different virtual desktop (virtual desktops are discussed in Chapter 7), which you can then dedicate entirely to The GIMP. Click Applications . Graphics . GIMP Image Editor to run The Gimp. When the program starts for the first time, it will run through its setup routine. Usually, you can use the default answers to the various questions asked by the wizard. After program has setup, you ll be greeted by what appears to be a complex assortment of program windows. Now you need to be aware of a second unusual aspect of the program: its reliance on right-clicking. Whereas right-clicking usually brings up a context menu offering a handful of options, within The GIMP, it s the principal way of accessing the program s functions. Right-clicking an image brings up a menu offering access to virtually everything you ll need while editing. Ubuntu includes the latest version of The GIMP, 2.2, and this features a menu bar in the main image-editing window. This is considered sacrilege by many traditional The GIMP users, although it s undoubtedly useful for beginners. However, the right-click menu remains the most efficient way of accessing The GIMP s tools. The main toolbar window, shown in Figure 20-1, is on the left. This can be considered the heart of The GIMP because, when you close it, all the other program windows are closed, too. The menu bar on the toolbar window offers most of the options you re likely to use to start out with The GIMP. For example, File . Open will open a browser dialog box in which you can select files to open in The GIMP. It s even possible to create new artwork from scratch by choosing File . New, although you should be aware that The GIMP is primarily a photo editor. To create original artwork, a better choice is a program like OpenOffice.org Draw (on the Applications . Office menu).

CHAPTER 20 Image Editing The PC has become an increasingly useful tool in the field of photography. In fact, these days it s hard to imagine a professional photographer who doesn t use a computer in some way, either to download digital camera images or to scan in images taken using traditional film- based cameras. Ubuntu includes a sophisticated and professional-level image-editing program called The GIMP. The title stands for GNU Image Manipulation Program. This chapter introduces this jewel in the crown of Linux software. Getting Pictures onto Your PC Before you can undertake any image editing, you need to transfer your images to your PC. Depending on the source of the pictures, there are a variety of ways of doing this. We have already looked at transferring images to your PC in Chapter 8, but let s briefly recap the procedure here. Most modern cameras use memory cards to store the pictures. If you have such a model, when you plug the camera into your PC s USB port, you should find that Ubuntu instantly recognizes it. An icon should appear on the desktop, and double-clicking it should display the memory card in a Nautilus window. Technically speaking, the memory card has been mounted (see Chapter 14 for an explanation of mounting). If your camera doesn t appear to be recognized by Ubuntu, you should consider buying a USB card reader. These devices are typically inexpensive and can read a wide variety of card types, making them a useful investment for the future. Some new PCs even come packaged with card readers. Most generic card readers should work fine under Linux, as will most new digital cameras. If your camera isn t recognized, however, or if it s a few years old and uses the serial port to connect to your PC, you can try using the gThumb software (Applications . Graphics . gThumb Image Viewer), as explained in Chapter 8. If you re working with print photos, negative film, or transparencies, you can use a scanner to scan them in using the XSane image scanning program, also covered in Chapter 8. This works in a virtually identical way to the TWAIN modules supplied with Windows scanners, in that you need to set the dots per inch (DPI) figures, as well as the color depth. Generally speaking, 300 DPI and 24-bit color should lead to a true-to-life representation of most photos (although because of their smaller size, transparencies or negative film will require higher resolutions, on the order of 1,200 or 2,400 DPI).

300 CHAPTER 19 MOVIES AND MULTIMEDIA Installing Tvtime To download and install tvtime, open Synaptic Package Manager (System . Administration), click the Search button, and enter tvtime as a search term. In the list of results, click the entry for tvtime and mark it for installation. Then click Apply. When the download has completed, you ll be asked a number of questions during the configuration process. First, you need to choose your TV picture format. Users in the United States should choose NTSC. Users in the United Kingdom, Australia, and certain parts of Europe should choose PAL. To find out which TV system your country uses, look up your country at www.videouniversity.com/standard.htm. You also need to choose your geographical area from the list so that tvtime can set the correct radio frequency range for your TV card. Once the program is installed, you ll find it on the Applications . Sound & Video menu. Figure 19-5 shows an example of tvtime in action. Using the program is straightforward, but if you need guidance, visit the program s web site at http://tvtime.sourceforge.net. Figure 19-5. If you have a TV tuner card, tvtime lets you watch TV on your PC! Summary In this chapter, we looked how you can watch movies on your PC. You ve seen how you can update Ubuntu to work with the most popular digital video technologies, such as Windows Media Player and QuickTime. In addition, we looked at how you can view online multimedia such as Flash animations on your computer, and discussed how you can watch TV on your PC. In the next chapter, we take a look at image editing under Ubuntu. You ll learn about one of the crown jewels of the Linux software scene: The GIMP.