This paper presents an image-based system for measuring target objects on an oblique plane based on pixel variation of CCD images by referencing to two arbitrarily designated points in image frames. Based on an established relationship between the displacement of the camera movement along the photographing direction and the difference in pixel counts between reference points in the images, object verticel height distance and photographing distance between the camera and an object on the target plane can be calculated via the proposed method. Because of the advantages demonstrated in measuring target objects on the oblique plane, the proposed approach is capable of acquiring 3-dimensional localization, imformation of the objects.To be practical for use in various applications, we also present a hardware/software (HW/SW) co-design approach using SOPC technique to realize the proposed image-based 3-dimensional localization method.