Changing Image Dimensions or File Type

Submitted by pwadmin on

Changing an image's dimensions

Any image editing program will do resizing. If you don't have anything else, the following programs are installed on most computers:

  • Windows: use  Paint (Start > All Programs > Accessories > Paint):
    • From the Image menu, click Stretch/Skew…
    • Choose a percent less than 100%.
  • Macintosh: use  Preview (click Finder, go to your Applications folder, and double-click Preview)
    • From the Tools menu, clickAdjust size...
    • Enter a width or height. Leave the other settings as-is for the best result.

Changing an image's file type (for a better file-size)

Most image editing programs will let you choose different file types. If you don't have anything else, the following programs are installed on most computers:

  • Windows: use  Paint (Start > All Programs > Accessories > Paint):
    • From the File menu, click Save as…The Save dialog will appear.
    • Enter a new name for the file (so you can tell it apart), but don't press Enter.
    • Choose a file type from the Save as type drop-down at the bottom of the Save dialog.
    • Click Save
  • Macintosh: use  Preview (click Finder, go to your Applications folder, and double-click Preview)
    • From the File menu, click Save as... (older Macs) or Duplicate... (newer Macs).The Save dialog will appear.
    • Enter a new name for the file (so you can tell it apart), but don't press Enter.
    • Choose a file type from the Format drop-down at the bottom of the Save dialog.
    • Click Save

Note: when saving JPEG files, you may see a Quality meter. A quality of 80% is the best for images on the web. Choosing a quality higher than 80% will not make a noticable difference, but the file size will become HUGE. You can experiment with lower qualities, but be warned that images will start to look blurry/blocky if you turn it down too far!