html5-img
1 / 32

Adobe Photoshop CS5 – Illustrated Unit B: Selecting Pixels

Adobe Photoshop CS5 – Illustrated Unit B: Selecting Pixels. Objectives. Use the Marquee tools Use the Lasso tools Use the Magic Wand tool Save and load selections. Objectives. Work with and save alpha channels Understand anti-aliased edges Work with a feathered edge

trey
Télécharger la présentation

Adobe Photoshop CS5 – Illustrated Unit B: Selecting Pixels

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Adobe Photoshop CS5 – IllustratedUnit B: Selecting Pixels

  2. Objectives • Use the Marquee tools • Use the Lasso tools • Use the Magic Wand tool • Save and load selections Adobe Photoshop CS5 - Illustrated

  3. Objectives • Work with and save alpha channels • Understand anti-aliased edges • Work with a feathered edge • Refine selection edges Adobe Photoshop CS5 - Illustrated

  4. Using the Marquee Tools • In order to modify pixels they first need to be selected • The Marquee tools are the most basic tools available for making selections in Photoshop • The Rectangular Marquee tool is used for making rectangular or square selections • The Elliptical Marquee tool is used for making oval or circular selections • Pixels can be added to an existing selection and can be removed from a selection by using quick keys Adobe Photoshop CS5 - Illustrated

  5. Using the Marquee Tools • The black triangle on some tool icons indicates that there are additional hidden tools beneath the currently displayed tool • If not happy with a selection then it can be deselected and started over Adobe Photoshop CS5 - Illustrated

  6. Using the Marquee Tools Positioning the first piece Repositioning the circle piece Adobe Photoshop CS5 - Illustrated

  7. CLASSROOM ACTIVITIES • True/False. The Elliptical Marquee tool is used for making oval or circular selections. (Answer: True) • What does the shift key do? (Answer: it adds to an existing selection, and it constrains a selection to a perfect shape) Adobe Photoshop CS5 - Illustrated

  8. Using the Lasso Tools • There are three types of Lasso tools in Photoshop • Lasso, Polygonal, and Magnetic • Lasso tools are used for making free-form selections • click and drag anywhere on the canvas to create a section of pixels • it is usually easier to make small selections and use the Shift key to add them to create a more complex shape • the Polygonal Lasso tool functions like the Lasso Tool but with straight lines making it great for selecting shapes that are geometric Adobe Photoshop CS5 - Illustrated

  9. Using the Lasso Tools Selecting the interior of the object Positioning the fifth piece Adobe Photoshop CS5 - Illustrated

  10. CLASSROOM ACTIVITIES • What are the three types of Lasso tools? (Answer: Lasso, Polygonal, and Magnetic) • Which key do you press to add small selections of pixels? (Answer: Shift) Adobe Photoshop CS5 - Illustrated

  11. Using the Magic Wand Tool • The Magic Wand tool is very powerful • Click any pixel on the canvas and the Magic Wand tool selects other pixels based on tolerance-the similarity of their colors • the greater the tolerance value that is set for the tool, the more pixels it will select • click the Contiguous check box on the Options bar to specify that the Magic Wand tool selects only pixels that are contiguous (touch) the area • otherwise the Magic Wand tool will select similar pixels throughout the image Adobe Photoshop CS5 - Illustrated

  12. Using the Magic Wand Tool • As with any selection, once the pixels are selected that are needed they can be modified in many ways • Zooming in on areas of the image that are to be selected always helps when making selections including colors using the Hue/Saturation dialog box Adobe Photoshop CS5 - Illustrated

  13. Using the Magic Wand Tool Selecting the white pixels Selecting pixels without the Contiguous option Results of changing the hue of selected pixels Adobe Photoshop CS5 - Illustrated

  14. CLASSROOM Activities • Discuss the difference between tolerance and contiguous. • What is the first step you should do before modifying the object? (Answer: Select it) Adobe Photoshop CS5 - Illustrated

  15. Saving and Loading Selections • Making selections can be some of the most complex and time-consuming work when using Photoshop • It makes sense then to be able to save selections with the Photoshop file • Saving a selection is always a smart idea so that it can be easily accessed in the future Adobe Photoshop CS5 - Illustrated

  16. Saving and Loading SelectionsSaving Color Swatches • The Swatches panel can be used to change the foreground and background colors • click a swatch and the foreground color changes • click the Eyedropper tool and sample any pixel from the image which also changes the foreground color • To save colors that are created, simply float the pointer over a white area of the Swatches panel; when the pointer changes to a paint bucket icon click to add the color as a new swatch Adobe Photoshop CS5 - Illustrated

  17. Saving and Loading Selections Save Selection dialog box Pure Yellow Orange swatch on the Swatches panel The finished project Adobe Photoshop CS5 - Illustrated

  18. CLASSROOM ACTIVITIES • What does posterize mean in Photoshop? (Answer: Posterize is a special effect that is created by reducing the number of colors available for the image) • True/False. You can create and save selections and fill them with different colors. (Answer: True) Adobe Photoshop CS5 - Illustrated

  19. Working with and Saving Alpha Channel • Alpha channels are simply saved selections • Alpha channels are listed on the Channels panel in Photoshop and are displayed as black and white thumbnail images • the selected areas are represented by white and the areas not selected by black • Alpha channels are not automatically saved when the file is saved; they need to be specified when saving a file Adobe Photoshop CS5 - Illustrated

  20. Working with and Saving Alpha Channel Save Alpha Channels option in the Save As dialog box The Dark Gray alpha channel Adobe Photoshop CS5 - Illustrated

  21. CLASSROOM ACTIVITIES • Where can you find the Alpha channels? (Answer: They are listed in the Channels panel in Photoshop) • What should you do if you begin working and the wrong foreground or background is selected. How would you make the corrections? Adobe Photoshop CS5 - Illustrated

  22. Understanding Anti-Aliased Edges • The outline of a selection is called the edge • The type of edge selected has a big impact on the work appears • the edge of a selection is always either aliased (hard edge which are very blunt and obvious) or • anti-aliased is a crisp but smooth edge • An anti-aliased edge in Photoshop creates a smooth transition between the edge and the background using many shades of edge pixel colors Adobe Photoshop CS5 - Illustrated

  23. Understanding Anti-Aliased Edges • Pixels are squares and a soft edge can not be made with squares; but the illusion can be created using anti-aliasing Viewing the aliased edge Viewing the anti-aliased edge Adobe Photoshop CS5 - Illustrated

  24. CLASSROOM ACTIVITIES • True/False. A square has a soft edge. (Answer: False) • How much resolution do most monitors have? (Answer: 72 pixels per inch) Adobe Photoshop CS5 - Illustrated

  25. Working with a Feathered Edge • A feathered edge is a blended edge • Photoshop offers settings for controlling the length of the blend at the edge • The feather value is equal to the length of the feathered edge • when the feathered edge is applied to a selection, the edge is equally distributed inside and outside the selection edge • A vignette is a visual effect created with a feathered edge • the edge of the image, usually oval, gradually fades away Adobe Photoshop CS5 - Illustrated

  26. Working with a Feathered Edge Drawing the feathered oval selection The selected pixels relocated Adobe Photoshop CS5 - Illustrated

  27. CLASSROOM ACTIVITIES • What is a feathered edge? (Answer: blended edge) • What is a vignette? (Answer: a visual effect in which an image gradually fades away) Adobe Photoshop CS5 - Illustrated

  28. Refining Selection Edges • The Refine Edge dialog box offers a number of useful options for viewing and refining the edge of a selection • Two key options in the dialog box are: • the Feather slider, used to dynamically feather a selection while previewing the result • the Contract/Expand slider, used to reduce of enlarge a selection • especially useful for removing halos from the edge of a selection Useful keyboard commands for the Refine Edge dialog box (Win & Mac) Adobe Photoshop CS5 - Illustrated

  29. Refining Selection Edges Selection The Refine Edge dialog box The silhouette of the eagle against black Adobe Photoshop CS5 - Illustrated

  30. CLASSROOM ACTIVITIES • What are the two key options in the dialog box? (Answer: the Feather slider and the Contract/Expand slider) • 2. What key allows you to toggle the Preview option on and off? (Answer: [P]) Adobe Photoshop CS5 - Illustrated

  31. Summary • The Marquee and Lasso tools provide different ways to select image pixels • The Magic Wand tool selects other pixels based on tolerance-the similarity of their colors • Saving selections makes it easy to access the selection in the future • After sampling a color of a selection, the color can be saved in the Swatches panel Adobe Photoshop CS5 - Illustrated

  32. Summary • Alpha channels are saved selections that need to be specified as an alpha channel to be saved when saving an image file • Images edges are made up of pixels that are square • a blunt square edge is an aliased edge • an anti-aliased edge is one that is made to look like a smooth edge • Edges can be feathered and refined Adobe Photoshop CS5 - Illustrated

More Related