New understanding on the effects of angle and position of biprism on single-lens biprism stereovision system

摘要

This paper provides a comprehensive study on the effect of the biprism angle and position on the field-of-view (FOV) of a single-lens biprism-based stereovision system. The image captured by this system consists of subimages that are regarded as virtual images taken by two virtual cameras. The overlapping area in a stereo-image pair constitutes the common FOV. Stereo-correspondence is only possible for objects placed in this common FOV region. A geometrical analysis of this system by tracing the rays enables an enhanced understanding of the system, both qualitatively and quantitatively. First of all, a simple geometrical approach is proposed to predict the type of FOV produced given a fixed biprism angle, α. A dimensionless coefficient, ε, is proposed to describe the different types of FOV. Second, the effect of the translation of biprism in the z- and x-axes on the system's FOV can also be determined using geometrical analysis. Experiments are conducted to verify the above predictions. Although there are some degrees of quantitative error between the experimental results and theory, the qeneral theoretical trends are larqelv supported bv the results.