There's no tool that can convert a complex 2d image in to a 3d model, simply because there is not enough data present in a flat image. Artists can use 3d modeling software and sample images to make models manually.
Simple images, like a 2d logo can easily be made into 3d using simple effects in photo editing software like Photoshop.
If it's an image is a complex one like a person, then it will have to be done manually.
FireNet is absolutely right. I don't know of any tool that can automatically take a 2D image, no matter how detailed, and turn it into a 3D render-able object. There's just not enough data in the 2D image. There are tools available to make it easier to MANUALLY do the job, some free, some really expensive.
I'm in the process of trying to learn Blender, one of the better free options out there. That would be a great place to start, if you're not already familiar with it.