Scanning and Graphics Workshop I

1
Scanning and Graphics Workshop I

• Graphics for the Web, Scanning and Introduction
  to Photoshop

2
Graphics Workshops

• I flatbed scanner and Photoshop basics
• II slide scanner and digital camera
• III Photoshop tricks - neat things to do with
  text, graphics, and file compression
• IV Clickable images
• animated gifs and graphics helpers

3

• Basic considerations of graphic-design for the
  Web
• Intro to Web graphic file formats
• Scanning paper documents
• Intro to graphic-editing with Photoshop
• File conversions

4
Web-Graphics Basics

• Basic Considerations
• Most common file formats are .gif and .jpeg
• 8-bit color
• 254 colors of Netscape

http//www.killersites.com/1-design/index.html
5
GIFs and JPEGS

• GIFs use an LZW compression algorithm and have
  lossless compressions (decompressed image looks
  just like the compressed image)
• uses linear pattern recognition for run-length
  encoding, so horizontal regularity is greatly
  compressable

6
GIF compression
941 bytes
1000
1001
1033
1102
1147
1186
1803
6685
7
GIFs and JPEGs, cont.
GIF 89a

• allows transparency, animation, interlacing, etc.

8
GIFs and JPEGs, cont.
JPEG

• best way to compress photographic images
  (continuous tone images)

9
Flatbed scanners

• mac and Windows 95 machines
• use scanner software for image acquisition
• use Photoshop for image manipulation and file
  conversion

10
Scanning

• scan as millions of colors, even if the
  original image is black and white
• save file as .bmp or.tiff

11
Photoshop

• Open file
• work with layers
• use image adjustment routines to compensate for
  bad scanning
• resize images for use on Web
• save images in a web formats

12
Saving in .GIF format

• select mode from the menu bar
• select indexed color
• say OK to flatten layers?
• select either 8-bits/pixel or Other for
  resolution - its up to you. However, because
  gifs are an indexed file format, the fewer colors
  you use, the smaller your file will be!

13

• select exact or adaptive for the palette
• click OK
• select file, save as, and be sure to select
  CompuServe GIF in the Save File as Format
  Type box.

14
Saving in JPEG format

• if you have more than one layer you must
  flatten the image
• save as JPEG (choose jpeg in Save File as Format
  Type box)