Most tutorial in using reference image for modelling with Blender 3D suggest you to assign the image into the background, which is quite cumbersome since you can't actually rotate or zoom in the 3D View Window without losing your image to mesh alignment. Even, panning the camera will mess your image to mesh alignment.
Most 3D modeller are using the reference images in the 3D space(world) itself, not in the separated background. So, this is why I would like to share how I set the image reference in Blender 3D.
First, of course you will need the image reference itself. For now, I'll just use one I found on CG Cookie site at https://cgcookie.com/max/2012/02/28/exclusive-resource-character-modeling-sheets-krystal/
Next is of course open Blender and add a Plane
Then, edit the plane to make something like this
The next step is to load the image and map the uv so you'll have the right view of the image when viewed from the right angle, that is, you got the front view when viewing the model from front, and the same when viewing from left/right, etc.
Also you might want to add Material into it and make it Shadeless.
Now adjust the model height so you have a good proportion.
There now you have an image reference in 3D view port. The next step is to prepare the 3D object you're going to working on.
Add another 3D object in to the scene.
Now here's the trick, do you notice that the new object is always shaded the way your preference is shaded. That is, when you switch to Wireframe, the reference model will be in Wireframe too. That's not good since you'll might want to view your reference Textured while the object you're working on in Wireframe(so you can always see the reference image while working the object).
Now go to object properties and set the Maximum Draw Type to Wireframe and viola...
Now I believe you can do it yourself from here ;)
Happy modelling...
