Fourier ptychographic microscopy with adaptive resolution strategy

Fourier ptychographic microscopy (FPM) is a method capable of reconstructing a high-resolution, wide field-of-view (FOV) image, where dark-field images provide the high- frequency information required for the iterative process. Theoretically, using more dark-field images can lead to results with higher resolution. However, the resolution required to clearly detect samples with different microscales varies. For certain samples, the limit resolution of the imaging system may exceed the one required to resolve the details. This suggests that simply increasing the number of dark- field images will not improve the recognition capability for such samples and may instead significantly increase the computational cost. To address this issue, this Letter proposes an adaptive resolution strategy that automatically assigns the resolution required for the sample. Based on a Tenengrad approach, this strategy determines the number of images required for reconstruction by evaluating a series of differential images among the reconstructions for a certain subregion and then efficiently completes the full-FOV reconstruction according to the determined resolution. We conducted the full-FOV reconstruction utilizing feature-domain FPM for both the USAF resolution test chart and a human red blood cell sample. Employing the adaptive resolution strategy, the preservation of reconstruction resolution can be ensured while respectively economizing approximately 76 degrees lc and 89 degrees lc of the time. (c) 2024 Optica Publishing Group