TYPO3 <f:image /> nest viewhelper or use the processed image somehow for lazyload

I'm trying to imply lazyload with a specific slider, it requests the src of the image to be entered twice, once as src and second as data-lazy like this:

<img src="domain.com/image.png" data-lazy="domain.com/image.png">

with <f:image /> I can use data="{lazy: 'domain.com/image.png'}" and should repeat the src of the image created with the viewhelper ... (typo3 documentation and the inline use of f:uri.image)

i have actually two questions:

• how do I nest f:uri.image ? this gives an error <f:image src="{image.uid}" treatIdAsReference="1" data="{lazy: '{f:uri.image(src: {image.uid})}'}"/>
• it should actually be the refference to the same image, if I nest f:uri.image would I create a second rendered image ? (especially because I also set width and height, but I wanted to keep the snippets simple)

the solution should work for TYPO3 v7 and v8

Try this

<img src="{f:uri.image(src : image.uid)}" data-lazy="{f:uri.image(src : image.uid)}" />

You don't have to use the <f:image ..> tag for creating the <f:uri.image ..> returns the same processed resource.