Zooming on text or on the page


I want to add a zoom-in and zoom-out feature in my ionic 2 app.
I am able to add zooming feature on image, but i want to add this feature in text as well as on page.
So please suggest me how can i achieve this.

Unexpected value 'HTMLImageElement' declared by the module 'AppModule'. Please add a @Pipe/@Directive/@Component annotation