Learning Basic Photoshop FIRST TIME Chapter 7

Chapter 7: Using Selections and Channels - End • Creating Selections in Quick Mask Mode • Creating a Selection with Color Range • Saving Selections with the Channels Palette • Exercises • Review Questions Creating Selections  in Quick Mask  Mode Photoshop  also permits you to use the various Painting Tools to create Selections .  We won’t be covering the Painting Tools just yet.  However, an introduction to how the Painting Tools function in Quick Mask  Mode  is essential. Restore the fudog image to its original state by using theHistory Palette  or by reloading the image.  {Click} the Edit in Quick Mask  Mode  button on the Toolbox .  Make sure the Background and Foreground colors are at default. Select the Airbrush Tool  and begin painting over one of the statue’s legs by {Clicking} and holding.  You’ll notice that instead of painting with Black, a very light Red color results.  In effect, you are painting the area you wish to make into a Selection.  Black adds to the selection, white subtracts from the selection.  If you {Click} the Swatches Tab in the Color Palette  Group  you’ll notice that all of the Swatches are different shades of gray.  Selecting different shades adds transparency to your selection, similar to the Feather effect, the darker the color the greater the transparency.  Once you are familiar with the Painting Tools, you can use them to make very complex Selections . {Click} Edit in Standard Mode to exit Quick Mask  Mode.  You’ll notice that the Marquee  or Selection area is outside the area you painted.  To reverse the Selection select Select/Inverse.  To force Photoshop  to make the area you painted the Selection area you have to set the Quick Mask Options. Quick Mask Options{Double-Click} either the Edit in Standard Mode  or Edit inQuick Mask  Mode button to activate the Quick Mask Options  dialog-box.

Color IndicatesCheck Selected Areas to force Photoshop  to make the area you paint with any of the Painting Tools the Selection area.  Select Masked Areas to force Photoshop to make the area outside of your painting area the Selection.

Color
{Click} the Color swatch to change the mask color from default Red to something else.  You’ll find this useful when you have to select an area with the same color as the Mask.  Changing it will make your editing easier.
Enter a different value in the Opacity  field to increase or decrease the opacity of the Mask.  This has no effect on the opacity level of the actual Selection, it affects how much of the image you can see while creating the Mask.

Creating a Selection with Color RangeRecall how the Magic Wand  works.  The Selection is created by analyzing a base color (which you designate by{Clicking} on it) and a range of related colors you determine by setting Tolerance.  You can also use theSelect by Color Range  function by selecting Select/Color Range.  The Color Range dialog-box appears.

Color Range  Dialog-BoxThe Color Range  dialog-box consists of a Selection option drop-down menu, Fuzziness controls (for fine tuning the range of your Selections ), an Image Box with the current image or Selection, Selection Preview options and 3 Color Picker s.

SelectUse the items in this menu to define how you are going to create your Selection.  You can choose by color range (from Reds, Yellows, Greens, Cyans, Blues, Magentas), by Sampled Colors (colors you select with the Color Picker s), by Contrast  (Highlights, Midtones, Shadows), and Out of Gamut (which applies to images created for Print.)  Generally, you’ll use Sampled Colors.

FuzzinessUse the Fuzziness to increase or decrease the selected color range.

Selection or ImageCheck Selection to display Selection data in the Image box.  Check Image to display the image. Selection PreviewSelect from None, Grayscale , Black Matte , White Matte, and Quick Mask  to display the Selection area and control how the Selection is displayed within the Image Window . Color PickersThere are three color pickers.  Use the Color Picker  without a “+” or “-“ symbol to select one color as the basis for creating your Selection and define the range by using the Fuzziness slider.  To add additional colors to your Selection use the Color Picker with the “+” sign.  To remove colors from your Selection use the Color Picker with the “-“ sign. Invert{Click} Invert  to reverse your current Selection. Restore the fudog image to its initial state.  Select Select/Color Range .  Make sure Selection is checked below the Image Box.  Select the Color Picker  without any signs.  You can use the Color Picker within the Image Box or on the Image itself.  {Click} on the Black Area of the fudog image.  A black mask covers most of the statue in the Image Box, indicating the unselected area. {Click} and drag the Fuzziness slider to a across its range to see how the selection is affected.  Adjust the Fuzzinessslider so that the statue is almost completely black and the background almost completely white.  {Click} Invert to reverse the Selection.  {Click} OK.  A Selection marquee surrounds the statue. Saving Selections  with the Channels PaletteYou might want to save your selections for future use as well.  To do so you use the Channels Palette . Load Selection, Save Selection, Create, Delete Channels

Restore the fudog image to its original state by using theHistory Palette  or by reloading the image.  Create a Selection using any one of the Selection Tools you wish, but make sure Feathering  is set to 0.  {Click} theChannels Tab in the Layers  Palette  Group .  You will see four channels: RGB, Red, Green, and Blue.  The RGB channel is a composite of the Red, Green, and Blue channels.

Color ChannelsThere are two types of Channels in Photoshop : Alpha and Color.  The fudog image is made of a combination of three color Channels, each containing a range of data relating to the primary colors in digital imaging, Red, Green, and Blue.  Recall that combining variations of Red, Green, and Blue can produce over 16 million colors.  Photoshop keeps the primary color information separate for editing purposes, most specifically for modifying color.  We will use Channels further on.  For now, {Click}the Visibility (the eye) Toggle beside the Channelthumbnails to Toggle the visibility of a color channel.  Notice how the color in the image drastically changes.  To restore the Channels simply {Click} the visibility Togglebeside each invisible channel or {Click} the VisibilityToggle of the RGB Channel to activate all the Channels. Alpha ChannelsWe use Alpha Channels  to save our Selections .  Alpha Channels do not store color data, rather they store grayscale data used to define and store Selections. {Click} Save Selection as Channel at the bottom of theChannels Palette .  An Alpha Channel is added below the color channels titled, “Alpha 1.”  To rename the channel simply {Double-Click} the Channel Box.  Rename accordingly. The Selection is saved as an Alpha Channel

Examine the Alpha Channel thumbnail.  You’ll notice that the channel is made up of pure black and white.  The black indicates the area of the image not selected and the white the area of the image selected.  If you haven’t already, deselect the Selection.  {Click} the VisibilityToggle beside the Alpha Channel.  The resulting composite now has a pinkish hue over the image with regular color showing through where the Selection was.  {Click} theVisibility Toggle of all the color channels to make them invisible.  Only the Alpha Channel is visible.  Notice again that the black area represents the area of the image not selected, while the white area represents the area of the image that is selected.  In effect, you can look at theAlpha Channel as a mask.  The white area is the hole in the mask.  When active as a Selection we can only manipulate the area of the image we see through that hole. Recall that we mentioned Alpha Channels  store grayscale data to define and store Selections .  Our current Alpha Channel has only black and white.  Different values or levels of gray indicate transparency when working with Selection Masks, that is, as the color range shifts from black, which is absolute transparency, to white, which is absolute opacity, various levels of transparency occur.  Recall what occurs when we feather a Selection.  The edge of the Selection gradually shifted to complete transparency.  Anything below the translucent or partially transparent areas shows through or mixes with the image above.

To demonstrate lets create an elliptical Selection with a Feather value of 20.  First, Toggle the visibility of theAlpha Channel to off and restore the color channels by toggling the visibility of the RGB Channel to on.  Next, select the Elliptical Selection Tool and set Feathering  to 20 in the Options  Palette.  Create an elliptical Selection with the fudog image.  Now use the Channels Palette  to create an Alpha Channel based on your new Selection.  Deselect your Selection and examine the new Alpha Channel by toggling the visibility of the other Channels.  Notice the elliptical area is pure white at the center and fades close to complete transparency toward the edge as color shifts to various shades of gray.  This is why Alpha Channels  work in grayscale, using 256 shades of gray to define transparency. Restoring Your SelectionWe created Alpha Channels  based on our Selections  so that we can restore the Selections at a later time.  When you save an image as a Photoshop  native document theAlpha Channels are saved with the file.  We’ll pretend that we saved the fudog image and have just reloaded it.  (You can save it as fudogchannel if you wish, close it and reopen it.)  Make sure both Alpha Channels are not visible by toggling visibility in the Channels Palette .  Make sure that you Toggle the visibility of the RGB Channel to on.  To restore your selection select Select/Load Selection.  The Load Selection dialog box appears. Load Selection dialog box SourceIndicates the source filename of the Alpha Channels , in this case “fudogchannel.psd.” ChannelUse the drop-down arrow to select which channel you want to restore the Selection from: either Alpha 1 orAlpha 2 unless you renamed the channels. Invert {Clicking} Invert  reverses the Alpha Channel values, switching black to white, white to black, and any intermediate grays accordingly.  As a result, your Selection will be inverted or reversed.  Modifications occur in the area of the image you did not initially select. OperationSelect New Selection, Add to Selection, Subtract from Selection, and Intersect  with Selection as you desire.  For the most part, you will select New Selection.  The other options are only available if the image already has an existing Selection active.  Experiment with these settings if you wish. {Click} OK.  Your Selection is restored. Exercises Open the window image from the chapter006folder.   Use the Magnetic Lasso Tool  or the Magic Wand  to create a Selection around the window. Use the Channels Palette  to convert the Selection into an Alpha Channel. Open the landscape image from the chapter006folder. Experiment with the History Palette  by painting on the image with the Airbrush Tool .  Try to select different colors by {Double-Clicking} the Foreground Color Swatch in the Toolbox . Use the History Palette  to remove your modifications and make new Snapshots. Review Questions What is the primary function of a Selection? What key do you press and hold to constrain the shape of Selections ? What Tool or type of Tool must you use to move the Selection Marquee  and not the image data currently within the Marquee? How does the Magnetic Lasso Tool  determine what part of the image to create a Selection path around? What effect does Contiguous and Discontiguous have on color based Selections ? Where are Selections  saved too? There are two types of Channels in Photoshop , they are? Summary As a result of this chapter, you should be able to Understand and create Selections. Understand Channels. Use the Channels Palette  to save Selections .