Photoshop is an image editing and graphic design program that allows users to create and manipulate digital images. It can be used to edit photos, restore images, create web graphics like GIFs and JPEGs, and more. When designing graphics for the web, there are several considerations including connection speeds, screen sizes, supported file formats, and how different formats compress images and colors differently. JPEG is best for photos, GIF for solid colors, and PNG has better compression than GIF while supporting more colors and transparency. Photoshop allows for color and tonal adjustments through tools like histograms, curves, and filters.

1. Photoshop: Designing Graphics for the Web

2. What is Photoshop?
Photo retouching, image editing, and color
painting program; graphic design tool
• Create high-quality digital images
• Tools & special effects capabilities
• Manipulate scanned images, slides, & original artwork
• Isolate parts of an image for experimentation &
individual editing
• And lots more…..

3. Uses of Photoshop
• Art (line drawings, charcoal, color original)
• Photographic
• Restoration
• WWW (GIFS, JPEGS, etc.)
• Montage
• Halftones, Duotones, Tritones, Quadtones
• Color Separations
• Posterizations
• Special Effects

4. Graphic Limitations
• Connection Speeds
• User Configurations

5. Display Considerations
• Screen Sizes
• Colors

6. File Formats
• JPEG – Joint Photographic Experts Group
• GIF – Graphics Interchange Format
• PNG – Portable Network Graphics

7. JPEG
• Best for photos or continuous tone, full-
color images
• Uses 16 million colors
• Browsers use reasonable approximations
• Work in RGB mode
• Uses lossy compression.

8. GIF
• Best for solid color images (buttons, logos)
• Uses 256 colors
• Browsers uses 216 colors
• Good compression

9. PNG (8-bit)
• Best for line art (logos)
• Compresses solid areas of color well and
maintains sharp detail
• Generally, has better compression than GIF
(10-30% smaller)
• If considering saving as GIF, also consider
saving as PNG (8-bit)
• Not supported by older browsers

10. PNG (24-bit)
• Best for continuous-tone images
• Compresses well, but can be larger than
JPEGs
• If considering saving as JPEG, could also
consider PNG (24-bit)
• Not supported by older browsers

11. JPEG vs PNG
Comparison
of JPEG and
PNG
68K PNG 31K JPG

12. GIF vs PNG
Comparison
of JPEG and
PNG
10.8K PNG-8 with 64 colors 9.5K GIF with 64 colors

13. Color & Tonal Adjustments
• Histograms
• Navigator Palette
• Gamma Settings
• Curve Controls
• Unsharp Mask Filter