Hi, so you need a url to open new form, and put the url as hyperlink somewhere on your page assigned to an image.
Assuming that the InfoPath template is already published on a SharePoint library, try clicking 'New' to open new form, and copy the url from browser's address bar, then past it notepad or your favorite editor and investigate it! that will give you the idea.
It's long; and you may omit some parameter(s) depends on the usage. XsnLocation is required parameter, and others are optional.
sample:
https://yoursite.com/subsite/_layouts/15/FormServer.aspx
?XsnLocation=https://yoursite.com/subsite/FormLibraryName/Forms/template.xsn
&SaveLocation=https://yoursite.com/subsite/FormLibraryName/
&ClientInstalled=false
&DefaultItemOpen=1
&Source=https://yoursite.com/subsite/FormLibraryName/Forms/AllItems.aspx
I usually try the url string with browser, and see which option(s) I need.