Use Resize to change an image's size to fit a specific width and height.

To change image size as a percentage increase or decrease in dimensions, use Scale instead.

For usage examples, see Resize images to fit an image grid or Dynamically resize images

If you add the IMQuery transformation to a policy, use the im variable, and select Resize, you can use a query string to resize an image using this policy. See Syntax and Examples for the syntax for the query string parameter.