As I already created a blog which has almost PR N/A, But I want to increase it's pr higher. If I upload some picture does it helps the blog to be a high pr?
Yeah, I don't really think that Images actually contribute to Page Ranking at all.. You'll have to wait for an expert to come along though, or search it up. 🙂
The only thing that matters for pagerank is that a lot of highly ranked sites link to yours. Because they're highly ranked and linking to your site it increases your site's ranking.
So images and even content are unimportant to page rank. (Though written content is certainly important for search engines indexing your site. Images? Not so much. So use a few images here and there to help illustrate a point but don't rely on them extensively or add them haphazardly expecting them to improve your site's pagerank.)