Abstract The paper demonstrates a composite method of transport-of-intensity equation (TIE)-based phase imaging for broad range of spatial frequency recovery. In TIE-based phase imaging, with the increase in distance between imaging planes, the range of well-resolved spatial frequencies in the retrieved phase reduces. Therefore, we need smaller image separation to recover accurately the higher spatial frequencies. Similarly, to recover accurately the lower spatial frequencies, larger separation is required. A phase image recovered from intensity data captured at large defocus distance provides well-resolved low spatial frequencies at the expense of higher spatial frequencies. On the other hand, a phase image recovered from small defocus intensity data provides higher spatial frequency content at the cost of lower spatial frequencies. To overcome the difficulty of high and low spatial frequency content in a single phase image, a composite phase image can be reconstructed. A combined image with the high- and low-pass filtered phase images has been reconstructed which provide both higher and lower spatial frequency information. As a proof-of-concept, experiments have been carried out with two different samples; a micro-lens and USAF chart.
展开▼
