Are you specifically targeting to rank a specific image, or is that image part of your site?
The fastest and easiest way to the have that image posted on an Authority site, properly formatted with alt codes, naming etc.
Have the image leeched and placed on several *other* websites, but hosted at your target location. [if on authority type site]
If you have a HTML5 webpage, ensure it's Microdata is set according (if that's the case, then scrap the meta content)
<div itemscope> <img itemprop="image" src="keywordTargetTerm.jpg" alt="keywordTargetTerm">
</div>
Have the image appear on multiple pages on your website (like footer, or featured posts as a sidebar).
Your website would still need to be pretty well optimized, but say you are tail-end pg1 or pg2, you can leapfrog the others using these direct methods for the image result in that category (if it is likely people will look at the image search).
I am sure you can do the same process for video (embedded on targeted sit, alt code for embed, microdata and on multiple pages).
Personally, I find naming images the most effective way, the other elements are overkill, however make sure you optimize for longtail keywords as well for a whole bunch of images on your website.