API for converting image to ZPL before send to Zebra printer


I am looking for Zebra official API for converting image to ZPL.
I am working with Zebra label printer.
I want to send ZPL with image but I can't find API which is converting image to ZPL.
Currently I am doing store image, then write ZPL. However, I want convert image to ZPL, then it add to ZPL so I only write ZPL without store image.
This is because storeimage() API has delay so I can't use printer buffer.

I am using iOS SDK and image can be different each case so I can't just put image ZPL from http://labelary.com/.

So if there is official zebra API for converting image to ZPL.
If there is solution for my case that I can use printer buffer.

Anyone help me with this ?

Thank you