Minimizing Graphics

Web graphics files should be as small as possible without compromizing image quality. Paint Shop Pro may be used to reduce gif and jpg (jpeg) files. The best way to find out the size of the image is to open Windows Explorer, then open the folder that contains the image file. The size is listed in KB (kilobytes). Paint Shop Pro also list the file size in the status bar to the right as you move the mouse over the image. That number is not always accurate.

Reducing GIF Files:

    Decreasing color depth
  1. Start Paint Shop Pro
  2. Open your image file
  3. From the menu bar select Colors, then Count colors used to see how many colors the image has
  4. From the menu bar select Colors, then Decrease color depth
  5. Make sure you choose a color depth value just high enough to cover the number of colors used in the image.
    Cropping the image
  1. In Paint Shop Pro open the image file
  2. Select the cropping tool from the Tool palette
  3. Select the part of the image you want to keep
  4. Click on Crop image in the Controls box
    Interlaced or Non-interlaced
    When a gif file is interlaced, the browser display the image in stages with a blurred image appearing first followed by a clearer and clearer image. This option takes up more space than a non-interlaced gif file. But it has the advantage that the user can see from the beginning whether the download is worth waiting for. As a gif file is saved, click on the Options button to choose Interlaced or Non-interlaced.
Reducing JPEG Files:

JPEG files are compressed image files like GIF files. You can control the rate of compression for JPEG files. In the Save As dialog box, click on Options. In the box that opens you can choose the % of compression you want. High compression means lower image quality and low compression means higher quality. You will have to see how much you can compress the image and still have the image quality you want. High compression also means small file size.
It is a good idea to keep a copy of the original file, because JPEG files lose image information in the compression process, which is called lossy.


Birte Nebeker
bnebeker@raritanval.edu