Does anyone know where You can get a jacket personalized with your own picture on the back full size
At an embroidery shop yes, but if you go on eBay they have a ton of embroidery shops and screen print shops that are fighting for business so you can get a much better deal. Plus they can do pretty much any image you send them in different formats.
Should be at any embroidery shop or store, just ask.
If you already have the jacket, head over to a custom Tee Shirt shop. There was one on the boardwalk in Seaside Park. Don't know if it survived Thursday's fire