As I wrote here before, the term 'body image' and 'body schema' are often used indiscriminatingly or confusingly. But it is important to clarify the difference.
Body schema is the system of sensory-motor capacities which functions without awareness when we control the movement or adjust the posture. Body image is the complex images of perceptions, thoughts, emotions, memories pertaining to one's own body.
In my view, there are at least three differences between body schema and body image.
Body image is a kind of image which can be represented in the mind. It is the intentional object for the consciousness; we perceive, think and feel our own body. Body schema coordinates body parts toward an action pre-consciously and we can never be aware of its function.
The body usually comes to one's senses as one's own body, not as other's. We perceive the body as something belonging to ourselves. This body is always perceived as 'my' body, not yours nor his/hers. In contrast, the function of body schema is anonymous, although it makes the person 'I' through its activity.
Body schema is not represented consciously. It is only lived from 'within'. Body image is the image of one's own body, which is perceived or looked from the 'outside'. To build such images, we need to borrow virtually the other person's viewpoint. Body schema is 'here' but body image is represented 'there'.