Structured light based sensors have attracted intensive research attentions in the fields of mobile robotics, computer vision and pattern recognition due to its super low cost and weight. But the depth image is known to be noisy, poor accuracy and incomplete. The application field of such depth sensor is therefore limited. In this paper, a 2D edge feature guided image filtering algorithm is proposed to enhance the depth measurement. An edge guidance image is used as the guided image, which is calculated based on a probabilistic feature correspondence window searching algorithm between 2D/3D features. Experimental result shows that the quality of the depth image around the edges is significantly improved if the correct correspondence has been found.