Changing the aspect ratio of a mask

Hi, I need to change the aspect ratio of a mask so that the mask fits my image when its aspect ratio changes. For example the mask is 16:9 which works fine when the image is 16:9 but when the image is 4:3 or something other than 16:9 it doesn’t fit. Is there anyway to adjust the aspect ratio of the mask or change the actual size of the mask to the size of the image?

i use scale to accomplish that:

https://docs.coronalabs.com/guide/media/imageMask/index.html