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Compressing Images


There are limitations on how photos are displayed on the web, and we can conserve storage space and improve CQ performance by making sure that we're not uploading unnecessarily large images. There are two main aspects of what makes up the file size of an image: Resolution and Dimensions.

  • Resolution: Most commonly measured in dots per inch (dpi). Every image on the web is displayed at the same resolution: 72 dpi
  • Dimensions: The width and height of an image. Computer monitors vary widely, but in the interest of accessibility we ask that your images are no larger than 1500 pixels wide or tall.

Authors should always compress their images to match these guidelines before uploading to DAM.

Note: With images to be used in the Image Rotator, they must match the intended dimensions of the component before being uploaded.

Compressing Images

If you're unsure of how to compress an image, here are a few options to explore.

Mac OS X

Preview in OS X makes compressing an image quick and easy.

  • Open an image.
  • Under the "Tools" menu, choose "Adjust Size..."
  • Ensure "Scale proportionally" is checked and your unit is "pixels."
  • Adjust image based on the guidelines on this page.

Windows 7, Vista

Windows Live Photo Gallery is a quick and easy tool to use for resizing. This application is part of Microsoft's Windows Live Essentials (free download).

Windows XP

Microsoft offers downloads for XP called PowerToys (free download), which are add-ons to the operating system. One of these is called Image Resizer, which allows you to resize multiple images with a right-click.


  • Resolution: 72 dpi
  • Dimensions: no more than 1500 pixels wide or tall.

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