Chapter 17

Creating Images for the Web

Chapter Lessons

• Learn about Web features• Optimize images for Web use• Create a button for a Web page• Create slices in an image

Creating Images for the Web

• Create images for use on the Web• Create buttons and other features unique to

Web pages

Photoshop and the Web

• Use Photoshop to create the images– Add interactive functionality to images that will be

viewed on the Web– Divide images into smaller, more manageable

parts– Create efficient Web-ready files

Previewing in the Browser

• Preview Web effects in a Web browser:– Click the Preview in Default Browser button in the

Save for Web dialog box

Understanding Slices

• Divide a Web site image into smaller sections called slices

• Use a slice to assign special features to specific areas within an image:– Links– Animations

Animations

• An image sequence: – Simulates an object moving on a Web page

• Create an animation by:– Making slight changes to several images– Adjusting the timing between the appearance of

each image

Converting an Image to HTML

• HTML is the language used to create Web pages

• Slices in an image become cells in an HTML table

• Animations become files in object folders

Optimize Images for Web Use

• Optimizing means:– Saving a file in a Web format that balances the

need for detail and accurate color against file size• Optimize an image to reduce file size and

make an image Web-ready

Image Comparison

• Compare an image in the following common Web formats:– JPEG (Joint Photograph Experts Group)– GIF (Graphics Interchange Format)– PNG (Portable Network Graphics)– WMBP (Bitmap format used for mobile devices)– Mobile development (currently evolving)

Save For Web Dialog Box

• Original View Tab– Displays the graphics without any optimization

• Optimized, 2-Up, 4-Up View Tabs:– Displays the graphic in the original format and in

other file formats such as GIF or JPEG

Optimizing Files

Original image format

Three optimized versions of the image in GIF and JPEG

format

Understanding Compression

• GIF, JPEG, PNG compression creates compressed files without losing substantial components

Understanding JPEG Files

• File compressed by discarding image pixels• Does not support transparent color• Known as “lossy” because it loses data when it

compresses a file

Understanding GIF Files

• Files compressed by limiting colors• 8-bit format• Maximum number of colors is 256• Supports one transparent color• Known as “lossless” because the file compresses

solid color areas but maintains details

Comparing Image TypesGIF optimization:

Colors are streaky and broken-up

JPEG optimization:Colors are crisp and appear

seamless

Optimization Format Considerations

Create a Button for a Web Page Defining Buttons

• Graphical interface that helps visitors navigate through and interact with a Web site– Create a new button shape– Apply a preformatted button style– Import a button created in another program– Assign actions to a button

Creating a Button

• Draw a shape with a shape tool on a layer• Apply a color or style to the shape• Add text to explain what will happen when the

button is clicked

Applying a Button Style

• Use one of many pre-designed button styles on the Styles panel

• Create a new style• Apply a style to a button by double-clicking

one of the button styles on the Styles panel

Button Styles

Converting Files to HTML• A Photoshop file must be converted to HTML before it can

be used on the Web• To convert a file to HTML:– Click Edit on the Menu bar, point to Copy HTML Code, click For

All Slices• Photoshop stores the HTML code on the Clipboard so that

it can then be pasted into the web page using an HTML editor

Create Slices in an Image

• A slice is a rectangular section of an image that is used to apply features such as links

• Slices are used to determine the appearance of special effects in a Web page

• Create a slice with any marquee tool or the Slice tool

Using Slices

• User-slice– The designer creates the slice– Enclosed in a solid line border

• Auto-slice– Photoshop creates the slice in response to the user-

slice– Enclosed in a dotted line border

Selecting a Slice

• A selected slice is bounded by a yellow border• Contains a bounding box and sizing handles• Resize a slice by dragging a handle

Slice Components

• Colored line used to identify the slice type• Overlay that dims the appearance of

unselected slices• Number that identifies each individual slice• Symbol that identifies the type of slice

Adjusting Slice Attributes

• Click Slices under the Preferences command on the Edit menu

• Choose to display slice lines, numbers, and symbols

• Specify line color, number, and opacity

User Slice Symbols

Using Layer-Based Slices

• Use the New Layer Based Slice command on the Layer menu to create a slice from a layer on the Layers panel

• Easy way of creating a slice without needing to draw an outline

Creating a Layer-Based Slice

• Select the layer on the Layers panel• Click Layer on the Menu bar• Click New Layer Based Slice– A new slice surrounds the selected layer

Slice Options dialog box

Web address of Web page: opens when user clicks on the

slice in a Web page

Assigning a Web Address to a Slice

• To assign a Web page address to a selected slice:– Type the URL of the Web page in the URL text box– The URL is the address of the Web page

Understanding Image Maps

• An image is divided into multiple areas:– Each area is assigned to a Web address

• Each area is known as a hotspot– When a user clicks the hotspot the browser opens

a different Web page