Abstract:
The dual camera system composed of the infrared camera and the depth camera has a widely application and the accuracy of spatial registration and temporal registration directly affects the integration of image information. However, the traditional calibration board cannot calibrate the infrared camera and the depth camera about spatial registration. In general, different materials may have different radiant rates. In order to deal with the spatial registration of the infrared camera and the depth camera, this paper designs a novel calibration board with different materials to achieve spatial registration. According to different radiant rates, the proposed calibration boards can solve the above shortcomings encountered in the traditional calibration board. In the temporal registration, many problems had to be taken into consideration. Different cameras might have different frame rates. Moreover, the frame rate may also fluctuate as the camera works. The precision difference of internal clock will bring cumulative time deviations to the camera image sequences. Furthermore, in order to maintain the accuracy measure signal of the temperature, the infrared camera will conduct regular non-uniformity corrections, which may yield about 1—2 s the time interruption of the camera. All of those above problems have impact on the temporal registration of cameras. To this end, this paper adopts adaptive search window to obtain the depth images and infrared images such that the effect of non-uniformity corrections from the infrared camera can be solved. By adaptively changing the size of the search window, the impact of the cumulative time deviations can be eliminated. Moreover, by calculating the mutual information between depth images and infrared images, we can obtain the depth images and infrared images that are temporal registration. Finally, the effectiveness of the proposed method is verified by experiments, which can effectively solve the temporal registration problem of different cameras with different frame rates.