Image rendering in android from raw binary data

I am using following code to render images: The code is working fine in ios but not working in android.
typescript code

this.http.get(url, {}, {})
  .then(data => {
     imgSrc = 'data:image/jpeg;base64,'+ btoa(data);

html code

<ion-thumbnail  item-start>
            <img [src]="imgSrc" >

I could find that the data from method btoa is different for ios and android. I am not sure if that is the reason.