What is Software? | What is Education? | What is Technology? | What is Research? | What is Wi-Fi? | What is Communication? | What is Customer Service?

Free SEO Tutorials & Help

Tutorials:   Adobe Flash   Adobe Photoshop   CorelDRAW   SEO  

Site Map

Website Development | Cable & Broadband Magazine | Solutions for Higher Education | Auction Anything Online

Adobe Photoshop Help & Tutorials

 Back to Topics

 

How to work with Selections in Photoshop

About selections

Top

There are separate sets of tools to make selections of bitmap and vector data. For example, to select bitmap pixels, you can use the marquee tools or the lasso tools.

To select vector data, you can use the pen or shape tools, which produce precise outlines called paths. You can convert paths to selections or convert selections to paths.

 

Adjusting pixel selections

Top

You can adjust and refine your pixel selections using the selection tools and a variety of commands in the Select menu.

In addition, you can apply geometric transformations to change the shape of a selection border.

 

Softening the edges of a selection

Top

You can smooth the hard edges of a selection by anti-aliasing and by feathering.

Anti-aliasing

Smooths the jagged edges of a selection by softening the color transition between edge pixels and background pixels. Since only the edge pixels change, no detail is lost. Anti-aliasing is useful when cutting, copying, and pasting selections to create composite images.

Anti-aliasing is available for the Lasso tool, the Polygonal Lasso tool, the Magnetic Lasso tool, the Rounded Rectangle Marquee tool (ImageReady), the Elliptical Marquee tool, and the Magic Wand tool. (Select a tool to display its options bar.) You must specify this option before using these tools. Once a selection is made, you cannot add anti-aliasing.

Feathering

Blurs edges by building a transition boundary between the selection and its surrounding pixels. This blurring can cause some loss of detail at the edge of the selection.

You can define feathering for the Marquee tool, the Lasso tool, the Polygonal Lasso tool, or the Magnetic Lasso tool as you use the tool, or you can add feathering to an existing selection. Feathering effects become apparent when you move, cut, copy, or fill the selection.

To use anti-aliasing:

  1. Select the Lasso tool, the Polygonal Lasso tool, the Magnetic Lasso tool, the Rounded Rectangle Marquee tool (ImageReady), the Elliptical Marquee tool, or the Magic Wand tool.
  2. Select Anti-aliased in the options bar.

To define a feathered edge for a selection tool:

  1. Select any of the lasso or marquee tools.
  2. Enter a Feather value in the options bar. This value defines the width of the feathered edge and can range from 0 to 250 pixels.

To define a feathered edge for an existing selection:

  1. Choose Select > Feather.
  2. Enter a value for the Feather Radius, and click OK.

    Note: A small selection made with a large feather radius may be so faint that its edges are invisible and thus not selectable. If a message appears stating "No pixels are more than 50% selected," either decrease the feather radius or increase the selection's size. Or click OK to accept the mask at its current setting and create a selection in which you cannot see the edges.

    Selection without feathering and with feathering A. Selection with no feather, same selection filled with pattern B. Selection with feather, same selection filled with pattern


Moving, copying, and pasting selections and layers

Top

You can move or copy selections and layers within or between images--and also between images in other applications.

 

Using the Snap command

Snapping helps with precise placement of selection edges, cropping marquees, slices, shapes, and paths. However, sometimes snapping prevents you from correctly placing elements. You can enable or disable snapping using the Snap command. You can also specify different elements to which you want to snap when snapping is enabled.

To enable or disable snapping:

    Choose View > Snap. A check mark indicates that snapping is enabled.

To specify what to snap to:

    Choose View > Snap To, and choose one or more options from the submenu:

    • Guides to snap to guides.
    • Grid to snap to the grid. You cannot select this option when the grid is hidden.

    more information about guides and the grid.

    • Slices to snap to slice boundaries. You cannot select this option when slices are hidden.
    • Document Bounds to snap to the edges of the document.
    • All to select all Snap To options.
    • None to deselect all Snap To options.

    A check mark indicates that the option is selected and snapping is enabled. A dot (Windows) or a dash (Mac OS) indicates that the option is selected but snapping is disabled.

To enable snapping for one Snap To option:

  1. With the Snap command disabled, choose View > Snap To.
  2. Choose an option. This automatically enables snapping for the selected option, and deselects all other Snap To options

 

Saving and loading selections

Top

Selections can be saved and loaded for reuse.

To save a selection:

    Choose Select > Save Selection.

To load a saved selection (Photoshop):

  1. Choose Select > Load Selection, and then enter the options in the Load Selection dialog window.
  2. Click OK to load selection.

To load a saved selection (ImageReady):

    Choose Select > Load Selection, and then choose an option from the submenu.

 

Deleting selections

Top

To delete a selection, choose Edit > Clear, or press Backspace (Windows) or Delete (Mac OS). To cut a selection to the Clipboard, choose Edit > Cut.

Deleting a selection on a background or on a layer with the Lock Transparency option selected in the Layers palette replaces the original location with the background color. Deleting a selection on a layer without Lock Transparency selected replaces the original area with the layer transparency

 

Removing fringe pixels from a selection (Photoshop)

Top

When you move or paste an anti-aliased selection, some of the pixels surrounding the selection border are included with the selection. This can result in a fringe or halo around the edges of the pasted selection. These Matting commands let you edit unwanted edge pixels:

    • Defringe replaces the color of any fringe pixels with the colors of nearby pixels containing pure colors (those without background color). For example, if you select a yellow object on a blue background and then move the selection, some of the blue background is selected and moved with the object. Defringe replaces the blue pixels with yellow ones.
    • Remove Black Matte and Remove White Matte are useful when you want to paste a selection anti-aliased against a white or black background onto a different background. For example, anti-aliased black text on a white background has gray pixels at the edges, which are visible against a colored background.

    You can also remove fringe areas by using the Advanced Blending sliders in the Layer Styles dialog box to remove, or make transparent, areas from the layer. In this case, you would make the black or white areas transparent. Alt-click (Windows) or Option-click (Mac OS) the sliders to separate them; separating the sliders allows you to remove fringe pixels and retain a smooth edge.

To decrease a fringe on a selection:

  1. Choose Layer > Matting > Defringe.
  2. Enter a value in the Width text box for the distance to search for replacement pixels. In most cases, a distance of 1 or 2 pixels is enough.
  3. Click OK.

To remove a matte from a selection:

    Choose Layer > Matting > Remove Black Matte or Layer > Matting > Remove White Matte.

 

Using the Extract filter (Photoshop)

Top

The Extract filter dialog box provides a sophisticated way to isolate a foreground object and erase its background on a layer. Even objects with wispy, intricate, or undefinable edges may be clipped from their backgrounds with a minimum of manual work. You use tools in the Extract dialog box to specify which part of the image to extract. You can resize the dialog box by dragging its lower right corner.

For simpler cases, try using the Background Eraser tool

When you extract the object, Photoshop erases its background to transparency. Pixels on the edge of the object lose their color components derived from the background, so they can blend with a new background without producing a color halo.

    Selected area highlighted and filled, and extracted object

    You can add back opacity to the background and create other effects by using the Edit > Fade command after an extraction.

To extract an object from its background:

  1. In the Layers palette, select the layer containing the object you want to extract. If you select a background layer, it becomes a normal layer after the extraction. If the layer contains a selection, the extraction erases the background only in the selected area.

    To avoid losing the original image information, duplicate the layer or make a snapshot of the original image state.

  2. Choose Filter > Extract, and then specify options for tools on the right side of the dialog box:
    • For Brush Size, enter a value, or drag the slider to specify the width of the edge highlighter, eraser, cleanup, and edge touchup tools. This setting affects the size of the Highlighter tool .
    • For Highlight, choose a preset color option for the highlight that appears around objects you choose with the Highlighter tool, or choose Other to specify a custom color for the highlight.
    • For Fill, choose a preset color option, or choose Other to specify a custom color for the area covered by the Fill tool.
    • If you are highlighting a well-defined edge, select Smart Highlighting. This option helps you keep the highlight on the edge, and applies a highlight that is just wide enough to cover the edge, regardless of the current brush size.

    If you use Smart Highlighting to mark an object edge that is near another edge, decrease the brush size if conflicting edges pull the highlight off the object edge. If the object edge has a uniform color on one side and high-contrast edges on the other side, keep the object edge within the brush area but center the brush on the uniform color.

  3. Specify Extraction options:
    • Select Textured Image if the foreground or background of your image contains a lot of texture.
    • For Smooth, enter a value or drag the slider to increase or decrease the smoothness of the outline.
    • To base the highlight on a selection saved in an alpha channel, choose the alpha channel from the Channel menu. The alpha channel should be based on a selection of the edge boundary. If you modify a highlight based on a channel, the channel name in the menu changes to Custom.
    • Select Force Foreground if the object is especially intricate or lacks a clear interior.
  4. Adjust the view as needed:
    • To magnify an area, select the Zoom tool in the dialog box, and click in the preview image. To zoom out, hold down Alt (Windows) or Option (Mac OS) as you click.
    • To view a different area, select the Hand tool in the dialog box, and drag in the preview image.
  5. Define the edge of the object you want to extract:
    • To draw a highlight that marks the edge, select the Edge Highlighter tool  in the dialog box, and drag so that the highlight slightly overlaps both the foreground object and its background. Use Smart Highlighting to trace sharper edges. Use a large brush to cover wispy, intricate edges where the foreground blends into the background, such as hair or trees.
    • If the object has a well-defined interior, make sure that the highlight forms a complete enclosure. You do not need to highlight areas where the object touches the image boundaries. If the object lacks a clear interior, highlight the entire object.
    • To erase the highlight, select the Eraser tool in the dialog box, and drag over the highlight. To erase the entire highlight, press Alt+Backspace (Windows) or Option+Delete (Mac OS).
  6. Define the foreground area:
    • If the object has a well-defined interior, select the Fill tool in the dialog box. Click inside the object to fill its interior. (Clicking a filled area with the Fill tool removes the fill.)

    Note: You can't highlight the entire object if you've selected Texture or Force Foreground.

    • If you've selected Force Foreground, select the Eyedropper tool in the dialog box, and click inside the object to sample the foreground color, or click in the Color text box and use a color picker to select the foreground color. This technique works best with objects that contain tones of a single color.
  7. Click Preview to preview the extracted object, or skip to step 10 to extract the object without a preview.

    Zoom in as needed, and set any preview options:

    • Use Show menu options to switch between previews of the original and extracted images.
    • Use Display menu options to preview the extracted object against a colored matte background or as a grayscale mask. To display a transparent background, choose None.
    • Select Show Highlight or Show Fill to display the object's highlight or fill.
  8. If necessary, repeat the extraction to improve the results (when you are finished, you can perform final touchups as described in step 9):
    • To perform another extraction after adjusting the highlight and fill, repeat steps 5, 6, and 7.
    • To perform another extraction with new extraction settings, change the Smooth, Force Foreground, or Color settings, and repeat step 7.

    Note: To specify the amount of smoothing of the extracted object, drag the Smooth slider or enter a value. It is usually best to begin with a zero or small value to avoid unwanted blurring of details. If there are sharp artifacts in the extraction result, you can increase the Smooth value to help remove them in the next extraction.

  9. Touch up the extraction results as needed:
    • To erase background traces in the extracted area, use the Cleanup tool . The tool subtracts opacity and has a cumulative effect. You can also use the Cleanup tool to fill gaps in the extracted object. Hold down Alt (Windows) or Option (Mac OS) while dragging to add back opacity.
    • To edit the edge of the extracted object, use the Edge Touchup tool . The tool sharpens edges and has a cumulative effect. If there is no clear edge, the Edge Touchup tool adds opacity to the object or subtracts opacity from the background.
  10. Click OK to apply the final extraction. On the layer, all pixels outside the extracted object are erased to transparency.

    Note: For best results in cleaning up stray edges, use the cleanup and Edge Touchup tools in the Extract dialog box. You can also clean up after an extraction by using the Background Eraser and History Brush tools in the toolbox.

 

About masks (Photoshop)

Top

Masks let you isolate and protect areas of an image as you apply color changes, filters, or other effects to the rest of the image. When you select part of an image, the area that is not selected is "masked" or protected from editing. You can also use masks for complex image editing such as gradually applying color or filter effects to an image.

Illustration of Examples of masks with these callouts: A. Opaque mask used to protect the background and edit the butterfly B. Opaque mask used to protect the butterfly and color the background C. Semitransparent mask used to color the background and part of the butterfly
Examples of masks A. Opaque mask used to protect the background and edit the butterfly B. Opaque mask used to protect the butterfly and color the background C. Semitransparent mask used to color the background and part of the butterfly

Masks and channels are grayscale images, so you can edit them like any other image. With masks and channels, areas painted black are protected, and areas painted white are editable. Masks let you save and reuse time-consuming selections as alpha channels. Alpha channels can store selections so you can use them again, or you can load a saved selection into another image.

Photoshop lets you create masks in the following ways:

Quick Mask mode

Lets you edit any selection as a mask. The advantage of editing your selection as a mask is that you can use almost any Photoshop tool or filter to modify the mask. For example, if you create a rectangular selection with the Marquee tool, you can enter Quick Mask mode and use the paintbrush to extend or contract the selection, or you can use a filter to distort the edges of the selection. You can also use selection tools, because the quick mask is not a selection. You can also save and load selections you make using Quick Mask mode in Alpha channels

Alpha channels

Lets you save and load selections. You can edit Alpha channels using any of the editing tools. When a channel is selected in the Channels palette, foreground and background colors appear as grayscale values.

Layer masks and vector masks let you produce a mix of soft and hard masking edges on the same layer. By making changes to the layer mask or the vector masks, you can apply a variety of special effects.

 

Using Quick Mask mode to make selections (Photoshop)

Top

To use Quick Mask mode, start with a selection and then add to or subtract from it to make the mask. Alternately, create the mask entirely in Quick Mask mode. Color differentiates the protected and unprotected areas. When you leave Quick Mask mode, the unprotected areas become a selection.

    A temporary Quick Mask channel appears in the Channels palette while you work in Quick Mask mode. However, you do all mask editing in the image window.

To create a temporary mask:

  1. Using any selection tool, select the part of the image you want to change.
  2. Click the Quick Mask mode button in the toolbox.

    A color overlay (similar to a rubylith) covers and protects the area outside the selection. Selected areas are left unprotected by this mask. By default, Quick Mask mode colors the protected area using a red, 50% opaque overlay.

    Selecting in Standard mode and Quick Mask mode A. Standard mode B. Quick Mask mode C. Selected pixels appear as white in channel thumbnail D. Rubylith overlay protects area outside selection and unselected pixels appear as black in channel thumbnail
  3. To edit the mask, select a painting tool from the toolbox. The swatches in the toolbox automatically become black and white.
  4. Paint with white to select more of an image (the color overlay is removed from areas painted with white). To deselect areas, paint over them with black (the color overlay covers areas painted with black). Painting with gray or another color creates a semitransparent area, useful for feathering or anti-aliased effects (semitransparent areas may not appear selected when you exit Quick Mask Mode, but they are).
    Painting in Quick Mask mode A. Original selection and Quick Mask mode with green chosen as mask color B. Painting with white in Quick Mask mode adds to the selection C. Painting with black in Quick Mask mode subtracts from the selection
  5. Click the Standard Mode button in the toolbox to turn off the quick mask and return to your original image. A selection border now surrounds the unprotected area of the quick mask.

    If a feathered mask is converted to a selection, the boundary line runs halfway between the black pixels and the white pixels of the mask gradient. The selection boundary indicates the pixels' transition from being less than 50% selected to more than 50% selected.

  6. Apply the desired changes to the image. Changes affect only the selected area.
  7. Choose Select > Deselect to deselect the selection, or save the selection.

    You can convert this temporary mask to a permanent alpha channel by switching to standard mode and choosing Select > Save Selection

To change the Quick Mask options:

  1. Double-click the Quick Mask Mode button  in the toolbox.
  2. Choose from the following display options:
    • Masked Areas to have masked areas appear black (opaque) and to have selected areas appear white (transparent). Painting with black increases the masked area; painting with white increases the selected area. With this option, the Quick Mask button in the toolbox appears as a white circle on a gray background .
    • Selected Areas to have masked areas appear white (transparent) and to have selected areas appear black (opaque). Painting with white increases the masked area; painting with black increases the selected area. With this option, the Quick Mask button in the toolbox appears as a gray circle on a white background .

    To toggle between the Masked Areas and Selected Areas options for quick masks, Alt-click (Windows) or Option-click (Mac OS) the Quick Mask Mode button.

  3. To choose a new mask color, click the color box, and choose a new color.
  4. To change the opacity, enter a value between 0% and 100%.

    Both the color and opacity settings affect only the appearance of the mask and have no effect on how underlying areas are protected. Changing these settings may make the mask more easily visible against the colors in the image.

 

Storing masks in alpha channels

Top

In addition to the temporary masks of Quick Mask mode, you can create more permanent masks by storing them in alpha channels. This allows you to use the masks again in the same image or in a different image.

You can create an alpha channel in Photoshop and then add a mask to it. You can also save an existing selection in a Photoshop or ImageReady image as an alpha channel that will appear in the Channels palette in Photoshop.

Selection saved as an alpha channel in Channels palette

 

Copyright ADOBE - All Rights Reserved Worldwide

 

 

More Topics:

Explore Work Area  in Photoshop

Key Board Shortcuts in Photoshop:

How to get an Image into Photoshop and ImageReady

Keys for selecting tools in Photoshop

How to Producing Consistent Color in Photoshop

Keys for selecting tools in the Extract toolbox in Photoshop

Working with Color in Photoshop

Keys for selecting tools in the Liquify toolbox in Photoshop

How to do Color and Tonal Adjustments in Photoshop

Keys for working with Extract*, Liquify, and Pattern Maker* in Photoshop

How to work with Selections in Photoshop

Keys for using the File Browser in Photoshop

How to work with Transforming and Retouching in Photoshop

Keys for using the Filter Gallery in Photoshop

Keys for using the Actions palette in Photoshop

Learn Drawing in Photoshop

Keys for using the Camera Raw dialog box in Photoshop

Keys for using the Animation palette in ImageReady

Learn Painting in Photoshop

Keys for using Photomerge in Photoshop

Keys for using the Brushes palette in Photoshop

How to use Channels in Photoshop

Keys for working with blending modes in Photoshop

Keys for using the Channels palette  in Photoshop

How to Work with Layers in Photoshop

Keys for viewing images in Photoshop

Keys for using the Color palette in Photoshop

How to apply Filters & Special Effects in Photoshop

Keys for selecting and moving objects in Photoshop

Keys for using the Color Table palette in ImageReady

How to use Character & Type in Photoshop

Keys for editing paths in Photoshop

Keys for using the History palette in Photoshop

How to Design Webpage in Photoshop

Keys for painting objects in Photoshop

Keys for using the Info palette in Photoshop

How to Create Complex Web Graphics in ImageReady

Keys for transforming selections, selection borders, and paths in Photoshop

Keys for using the Layer Comps palette in Photoshop

How to Develop Graphics for Web in Photoshop

Keys for selecting, editing, and navigating through text in Photoshop

Keys for using the Layers palette in Photoshop

How to Save & Export Images

Keys for formatting type in Photoshop

Keys for using the Paths palette in Photoshop

How to Print in Photoshop

Keys for slicing and optimizing in Photoshop

Keys for using the Swatches palette in Photoshop

How to Create Automated Tasks in Photoshop

Keys for using palettes in Photoshop

(F) Function keys in Photoshop