High Dynamic Range Panoramic Imaging

Most imaging sensors have a limited dynamic range and hence can satisfactorily respond to only a part of illumination levels present in a scene. This is particularly disadvantageous for omnidirectional and panoramic cameras since larger elds of view have larger brightness ranges. We propose a simple modi cation to existing high resolution omnidirectional/panoramic cameras in which the process of increasing the dynamic range is coupled with the process of increasing the eld of view. This is achieved by placing a graded transparency (mask) in front of the sensor which allows every scene point to be imaged under multiple exposure settings as the camera pans, a process anyway required to capture large elds of view at high resolution. The sequence of images are then mosaiced to construct a high resolution, high dynamic range panoramic/omnidirectional image. Our method is robust to alignment errors between the mask and the sensor grid and does not require the mask to be placed on the sensing surface. We have designed a panoramic camera with the proposed modi cations and have discussed various theoretical and practical issues encountered in obtaining a robust design. We show with an example of high resolution, high dynamic range panoramic image obtained from the camera we designed.