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.extends.Enter a value in pixels.2 Start converting the selection:" Anti-aliased to create a finer transition betweenthe pixels in the selection and the surrounding " Alt-click (Windows) or Option-click (Mac OS)pixels.Make sure the Feather Radius is set to 0.the Make Work Path ( ) button at the bottom ofthe Paths palette.For more information on these options,see Softening the edges of a selection on " Choose Make Work Path from the Pathspage 147.palette menu." Click the Make Work Path button.This converts5 Select an Operation option:the selection using the current settings (you can" New Selection to select only the area defined byskip steps 3 and 4).the path.3 Enter a Tolerance value or use the default value" Add to Selection to add the area defined by thein the Make Work Path dialog box.path to the original selection.Tolerance values can range from 0.5 to 10 pixels" Subtract from Selection to remove the areaand determine how sensitive the Make Work Pathdefined by the path from the original selection.command is to slight changes in the selection" Intersect with Selection to select the areashape.The higher the tolerance value, the fewercommon to both the path and the originalthe anchor points used to draw the path and theselection.If the path and selection do not overlap,smoother the path.If the path is used as a clippingnothing is selected.path and you have problems printing the image,use a higher tolerance value.(See Printing image6 Click OK.clipping paths on page 370.)4 Click OK.The converted selection appears as awork path at the bottom of the Paths palette. CHAPTER 6182Drawing and EditingAdding color to paths(Photoshop)You can add color values to a path by filling orstroking it.Filling a path is the same as creating arasterized shape using the shape tools.(See Creating rasterized shapes on page 164.)For more information, see Filling pathswith color and Stroking to paint pathborders in online Help.Transforming and retouchingYou can transform images in many ways.For example, you can redefine an image sperspective; manipulate areas of an image as if thepixels in those areas had been melted; scale, rotate,or flip a selection or image in two dimensions;and transform an object in three dimensions.You can also apply filters to create special effects.Tools for retouching an image include the clonestamp, pattern stamp, smudge, blur, sharpen,dodge, burn, and sponge tools.For more information on transforming andretouching an image, see Transformingand retouching in online Help.For informationon filters, see Applying filters for special effects inonline Help. 7 185Chapter 7: Using Channels and Masksach image in Adobe Photoshop has The file size required for a channel depends onchannels that store information about the the pixel information in the channel.(See AboutEimage s color.You can create additional image size and resolution on page 92.) Certainchannels to store spot colors for printing with file formats, including TIFF and Photoshopspecial inks and to store masks for sophisticated formats, compress channel information andselections.can save space.(See Managing channels(Photoshop) on page 187.) The uncompressedsize of a file, including alpha channels and layers,About channels appears as the rightmost value in the status bar atthe bottom of the window when Document SizesPhotoshop uses special grayscale channels to storeis chosen from the pop-up menu.an image s color information and informationabout spot colors.If an image has multiple layers,Note: As long as you save a file in a formateach layer has its own set of color channels.supporting the image s color mode, the colorchannels are preserved.Alpha channels are preservedColor information channels are createdonly when you save a file in Adobe Photoshop, PDF,automatically when you open a new image.PICT, TIFF, or Raw formats.DCS 2.0 format onlyThe image s color mode (not its number of layers)preserves spot channels.Saving in other formats maydetermines the number of color channels created.cause channel information to be discarded.For example, an RGB image has four default(See About file formats on page 364.)channels: one for each of the red, green, and bluecolors plus a composite channel used for editingthe image.Using the Channels paletteYou can create alpha channels to store selections as(Photoshop)8-bit grayscale images.You use alpha channels toThe Channels palette lets you create and managecreate and store masks, which let you manipulate,channels and monitor the effects of editing.isolate, and protect specific parts of an image.The palette lists all channels in the imageSaved selections in alpha channels can be loaded incomposite channel first (for RGB, CMYK, and LabImageReady.(See Loading a selection into animages), then individual color channels, spot colorimage on page 201.)channels, and finally alpha channels.A thumbnailIn addition, you can create spot color channels toof the channel s contents appears to the left of thespecify additional plates for printing with spotchannel name; the thumbnail automaticallycolor inks.An image can have up to 24 channels,updates as you edit the channel.including all color and alpha channels. CHAPTER 7186Using Channels and MasksViewing channels " In alpha channels, selected pixels appear aswhite; unselected pixels appear as black (partiallyYou can use the palette to view any combination oftransparent or selected pixels appear as gray).individual channels.For example, you can view anThese are the channel default options.alpha channel and the composite channel togetherto see how changes made in the alpha channel" If you display an alpha channel at the same timerelate to the entire image.By default, individualas color channels, the alpha channel appears as achannels are displayed in grayscale.transparent color overlay, analogous to a printer srubylith or a sheet of acetate.To change the colorTo display the Channels palette:of this overlay or set other alpha channel options,see Creating alpha channels (Photoshop) on1 Choose Windows > Show Channels, or click thepage 200.Channels palette tab.2 Use the scroll bars or resize the palette to seeChanging the display of the paletteadditional channels.You can show the individual color channels inWhen a channel is visible in the image, an eyecolor (rather than grayscale) in the Channelsicon ( ) appears to its left in the palette.palette and specify the size of the thumbnails
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