In the following example we are requesting a 300 pixels wide by 300 pixels high image from a 1365 pixels wide by 767 pixels high image.  Notice in Figure 1 that even though a size of 300x300 was requested in the URL, ITS returns an image with a size of 300x168.  This is because ITS retains original image aspect ratios.  In other words, ITS reduces the image according to the largest of the two dimensions and the other dimension is often reduced beyond the requested size to avoid image distortion.  In the example below, because the width is larger than the height, the width will be reduced to the requested size of 300 but the height will go much smaller to maintain the aspect ratio. 

Original image: https://image.pbs.org/video-assets/GTdD9Rq-asset-mezzanine-16x9-d3h7qCm.jpg

Actual image size: 1365x767


Resized image: https://image.pbs.org/video-assets/GTdD9Rq-asset-mezzanine-16x9-d3h7qCm.jpg?resize=300x300

Actual image size: 300x168


To visually demonstrate aspect ratios, Figure 2 displays three images:

  1. the original mezzanine image (640x360)
  2. the resized image from ITS (300x168)
  3. the image reduced to the exact requested dimensions (300x300) 

Figure 2