Scanning images - Images for the web - Web Team - University of Canterbury - New Zealand

Scanning images

  • Before scanning images make sure you are complying with the Copyright Act 1994 and Privacy Act 1993. See Copyright and Privacy
  • Keep a file of original images scanned until you have completed preparing the image for the web. If needed you can easily access a replacement
  • If your scan is only to used on the web, scan at 75 - 100dpi
  • If your scan is to be used both for web and print, scan at 300dpi (for print). Use Photoshop Elements to change the resolution to 72 dpi for the web. ('Save for web' automatically changes resolution to 72dpi)
  • To save time and reduce file size crop pictures before you scan them. Most scanner software provide a crop tool. Use this to select a specific area of an image to scan

Save images as uncompressed or compressed

Uncompressed image types

Uncompressed file formats are: .tif and .bmp.

Advantage
  • Retain as much information as possible
  • Can be compressed later after editing
Disadvantage
  • Create large files, which you will have to store either on your computer's hard drive, P: drive, K: drive or burn to CD
  • Over-kill and takes more time if image is only to be used on the web

Compressed image types

  • JPEG (.jpeg) file for photos
  • GIF (.gif) file for images with few colours
Advantage
  • Saves time if image is only to be used on the web
  • Creates smaller files - takes less storage space on your hard drive, P: drive or K: drive
Disadvantage
  • If you later decide you need a higher quality image you will need to re-scan (you can't add quality to an image later)