Below is a high resolution file with a size of 3648 pixels wide by 2736 pixels high. Let's say you need to fit this image into a space where only the width is known. No problem! Simply add the width to the URL, leave the height blank and ITS will resize the image to the known specification. Because image sizing convention is always width x height, the request string will look like this: http://image.pbs.org/demo/demo1.jpg.resize.200x.jpg. The width (200) is included but the height is left blank.
Figure 3 shows resizing by width only.