Just read my previous post - not well written, here is another attempt,
I have seen this question many times on various forums, with the rise in particular of 3D printing a lot of people are interested in trying to pull 3D information out of 2D photos.
In general a single photograph cannot supply you with sufficient information to capture 3D shape, if you close one eye you lose the ability to judge distance, thats why you have two eyes and old fashioned miltary range finders use two objective lenses distanced as far as practical from one another.
If you have two photos of the same scene taken from different angles you can in principle recapture 3D information although this method will generally capture
overall shape rather than fine detail. The clue is to be had in the file format name STL ( stereo lithography - that was one of the first file formats for dealing with 3D shape capture ).
The general area of interest is called photogrammetry - there are loads of articles online on this topic but a lot is not intended for the non-expert, its a hot topic at the moment, archeologists are using cameras on radiocontrolled helicopters to 3D scenes (on the cheap) so it scales up easily, similar uses by accident investigators and of course there are many many young folks out there all fired up about 3D printing who cannot afford 3D scanners and are interested in
One type of image that does give reasonable 3D information ( with just one image ) is a displacement map - this is typically a B/W image where a white pixel represents a point that is close to the camera and a black point represents one that is far away. This is actually the type of image you would ideally use to create a relief in vectric but the question "where do I get a displacement map image from" is unfortunately chicken and egg because in general you need to have the full 3D data to create the displacement map.
If you take an ordinary black and white image and import it into vectric and create a relief you will see that ordinary images are not displacement maps, sometimes white points are far away and sometimes close points are black. If you had a suitable displacement map image of the same and used that in vectric
you would see that you had captured the shape - the issue is how to get the displacement map and the simple answer is that you cannot unless you have
at least 2 photos from different angles with which to create it and then the process is not easy and requires specialist software.
Once you have the idea of a displacement map image in mind you sometimes spot B/W images that are by chance actually reasonable displacement maps, I have B/W photos and drawings of the Jazz greats on my walls and sometimes just by chance and accident of lighting the regular image would actually serve as a reasonable starting point for a displacement map - by chance the white areas are actually the ones closest to the camera - there is an element of luck in this, moody high contrast highlighting is usually the most successful.
There is nothing to stop you taking your B/W photo and modifying it in a paint package using your imagination to try and grade areas into height and then filling in with white or black according to your judgement, I have seen people do this successfully but personally I didnt have a lot of luck with it.
If you want to create abstract designs then you may well find that a paint package and black and white images is an ideal place to start, you are painting in white and black and all shades in between but actually in your mind you are "painting height" - I see this as a very viable technique but limited in scope.
If you have only one photo then you cannot in general re-create a realistic 3D relief.
If you have two suitable photos from different angles then you can in principle but expect a learning curve.