Google always cares for the white hat SEO method. Image submission is a sensitive task, some people can manipulate your site by giving bad sources of submission so be careful.
100% manual High PR Backlinks will surely improve your viewers.
A few High PR sites are:
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Site Page Ranking
flickr ----------------> 9
Pinterest -----------> 9
issuu ----------------> 8
imgur ----------------> 8
Slideshare ------------> 8
I will: