How to encode and decode image to base64 to save server

want to encode the uploaded files to base64 so that I can pass them to the request. The problem is that I'm using Angular 2 with Typescript and I couldn't find any info on how to do that. I found that in Javascript it can be done with canvas but I don't know how could I implement the code in Typescript. Even I need to know how to bind the coming base64 image in html please help me

What I have tried:

I am getting all other json data except base64.I need to bind it as an image.same way I need to post also

my html here, user can upload image here as jpeg

while binding am getting base64 only, how to convert this?. with in one API I need to get

how can I achieve this?