1. Chapter 6 Raster Editing
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2. Lessons
Lesson 6.1: Becoming Familiar with the Raster Editing Workspace
Lesson 6.2: Using Tools to Make Selections
Lesson 6.3: Digital Photos: Fixing Common Problems and Enhancing Images
Lesson 6.4: Introduction to Layers and Layer Masks
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3. Learning Outcomes
6.1: Be familiar with a basic raster editing workspace and common tools
6.2: Select portions of an image for editing by using selection tools
6.3: Recognize common settings for certain selection tools
6.4: Make and refine selections by using Quick Mask mode
6.5: Adjust levels, brightness, and contrast in photos using curves
6.6: Use a cropping tool to adjust photo composition
6.7: Edit a photo by using retouch tools
6.8: Understand the usefulness of layers and layer masks in nondestructive editing
6.9: Use layers and layer masks to edit digital images
6.10: Manage file size in files with multiple layers
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4. Navigation Tools
A zoom tool is a navigation tool that magnifies or reduces the view of an image
A hand tool is a navigation tool that moves an image around in a viewing area
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5. Foreground and Background Color
The foreground color is what appears when you paint, draw, or fill in part of an image
The background color appears when you select and delete an area of an image on the background layer; the color “behind” a raster image
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6. Using Tools to Make Selections
A selection tool is a type of tool used to select a portion of a raster image before modifying it
When you use a selection tool, the area you select is outlined with a moving dashed line, sometimes called “marching ants”
Once an area is selected, you can use other tools and features to make changes to only that portion of the image
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7. Photoshop Selection Tools
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8. Photoshop Selection Tools (continued)
To make a selection of a clearly defined shape with one of the marquee tools, click the tool and then click and drag around the item you wish to select
To make a selection of an irregularly-shaped item, you can:
Use the Lasso tool to draw freehand around the item
Make the selection using the Magic Wand, Magnetic Lasso, or Quick Selection tools
You can cancel a selection in Photoshop by selecting Deselect from the Select menu or by using keyboard shortcuts: Ctrl+D (PC) or Cmd+D (Mac)
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9. Selection Settings Anti-Aliasing and Feathering
Anti-aliasing is a raster- editing feature that softens the hard edges of a selection by adjusting the color of the pixels along the outside edge
Feathering is a raster-editing feature that softens the hard edges of a selection by adding a border along the outer edge that gradually fades into the background, creating a soft blur
Susan Lake
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10. Selection Settings (continued)
Additional Magic Wand Tool Settings
Tolerance is a setting that determines the range of pixels affected by a raster editing tool’s action; in Photoshop, this is a setting for the Magic Wand tool
Contiguous refers to pixels that “touch”; if the contiguous setting is selected, only pixels that are touching will be included in the selection when you click an image with the Magic Wand
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11. Quick Mask Mode
Quick masks, a temporary mask, enable you to make and refine selections using the Paint Brush tool
When you make a selection, you are essentially protecting the unselected area of the image from any changes you make to the selected area inside the marching ants
If you make a selection using one of the selection tools and then click the Quick Mask mode icon on the toolbar, a ruby-colored overlay appears over the entire image except the selected area
Quick Mask mode is useful for refining a selection of an irregular shape in an image, especially if you use the Zoom In tool to magnify the area before you use the Paint Brush tool to adjust the quick mask
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12. Adjusting Brightness and Contrast
Highlights represent the lightest part of an image
Shadows represent the darkest part of an image
Midtones represent the middle range or an image
Adjusting the levels of any of these three areas can dramatically improve a picture
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13. Cropping
You can use the cropping tool in raster editing software to achieve good composition
Photo Courtesy of Megan Smith-Creed
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14. Using Retouch Tools
Raster editing software features retouch tools that enable you to alter the content of an image
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15. Retouch Ethics
Is it ethical to drastically change a person’s or product’s appearance for marketing purposes?
What about using photo editing tools to enhance your profile picture on a social networking site?
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16. Understanding Layers
Layers are a raster-editing feature that enable you to layer editable images individually, make changes, add effects, and make nondestructive edits; add layers to:
Combine and overlap multiple images
Draw vector shapes on a raster image
Add text to an image
Change the order of overlapping items
Adjust the position of different elements
Apply special effects and filters
A non-destructive edit is a change made to an image that does not actually alter the original image’s pixels
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17. Background and Normal Layers
A background layer is a special kind of layer in raster programs like Photoshop that is always at the bottom of the layer stack and cannot be renamed, moved, or deleted or contain any transparency
A background layer has certain restrictions:
It is always the bottom layer no matter how many other layers you add
It cannot be renamed
It cannot be transparent
It cannot be moved or deleted
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18. Basic Layer Actions
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19. Layer Styles and Adjustment Layers
Name layers using logical and understandable names
You can add color and other details to layers
You can add special effects to a layer
To change an adjustment, click the adjustment layer in the Layers Palette and make changes in the Adjustments Panel
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20. Understanding Layer Masks
Layer transparency can vary from completely see-through (0%) to completely solid (100%)
Layer transparency is applied to everything on the layer equally
A layer mask is a raster-editing feature that enables you to control what is visible on a layer
You can use a mask in combination with an adjustment layer to apply an effect to only a specific area of a layer
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21. Layers and Layer Masks in Action
Original image set as the background layer
Photo Courtesy of Megan Smith-Creed
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22. Layers and Layer Masks in Action (continued)
Zoom in on the head of the statue; select the head of the statue and add a Levels adjustment layer; use the Levels settings to lighten just the selected face
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23. Layers and Layer Masks in Action (continued)
When you draw a text box, a text layer is automatically added to the image
Add a layer style and adjusted the style settings
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24. Layers and Layer Masks in Action (continued)
Add a new layer and used the Clone Stamp tool to obscure the portion of the building behind the fountain that was showing in the bottom left corner of the image
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25. Layers, File Size, and File Format
If you save a layered image in a file format that is native to the image editing software, the layers will remain available to you even after you have closed the file
If you save your image as a .JPG or other non-native file format, the layers will be merged into a single image and you will no longer be able to edit them individually
Layers contribute to large file sizes, so the benefit of merging multiple layers into a single layer is a smaller file
To flatten is to merge multiple layers into a single layer; flattening can reduce file size, but should only be done after all editing is complete and is best done on a copy of the original file
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26. Key Concepts
Many raster editing programs have similar workspaces and basic tools
For certain tasks in raster editing, you must first select a specific area to edit by using a selection tool or a feature like Photoshop’s Quick Mask mode
Some selection tools include settings such as anti-aliasing, feathering, tolerance, and contiguous options that enable you to enhance the effect or precision of a selection
Quick Mask mode helps you refine a selection
You can adjust levels, brightness, and contrast in photos using curves
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27. Key Concepts (continued)
A cropping tool in a raster editing program can help improve photo composition
Retouch tools make it possible to alter large and small imperfections in an image
One of the most important uses of layers and layer masks is non-destructive editing. Since layers add to file size, you can choose to merge several layers into one by saving in a non-native format or by using a flatten image feature in a raster editing program
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