Information leaking from interior envi ronments like meeting room,drama theatre,technical lab and private space may cause serious social pr oblems or commercial losses.To solve the critical problems,this study proposes a portable handheld system based on the DSP+FPGA structure to detect the interior cat-eye targets i n real time. Firstly,it utilizes a narrowband filter to discriminate the potential targets f rom the background by adaptive thresholding on the basis of the cat′s eye effect.Secon dly,it reduces the false positives by multiple morphological constraints.At last,a no vel comprehensive shape criterion is presented to recognize the true target.The alg orithm is implemented on the DSP+FPGA platform with a pipeline design.To validate our algorithm and system,experiments of 20different lab scenes with complex background and interference are taken repeatedly.As the results indicate,the true target can be recognized accurately and rapidly in scenes with different kinds of interferenc es and different degrees of complexity by the proposed algorithm and system.The results also indicate that the average time cost is 34－53ms,which is superior to that of th e current methods.