The most challenging issue of the navigation assistive systems for the visually impaired is the instantaneous and accurate spatial localization of the user. Most of the previous proposed systems based on GPS sensors have clearly insufficient accuracy for pedestrian use and are confined to outdoor with severe failing in urban area. This paper presents an interesting alternative localization algorithm using a body mounted single camera. Instantaneous accurate localization and heading estimates of the person are computed from images as the trip progresses along a memorised path. A first portable prototype has been tested for outdoor as well as indoor pedestrian trips. Experimental results demonstrate the effectiveness of the vision based localization to keep the walker in a navigation corridor less than one meter width along the intended path. Future works will investigate multimodal adaptative interface taking account the psychological and ergonomic factors for the blind end-user to design a suitable guiding solution for the blind and visually impaired.