How to center dynamic images (via Powerpoint templates) with different width?

In Powerpoint I am using a dynamic image, something like this: {$imageVariableName|insert_image:117:0:0:41}

The potential images differ in width. The resulting PDF file has the image aligned on the left. The image should be aligned in the center. Is this possible?

This is the result I want (for the 2nd images):

This is the result I get:

How to center the dynamic image?