Based on the extended ptychographical iterative engine (ePIE) algorithm, the effects of the incident probe size, scanning position number, and wavefront morphology on the reconstructed image were systematically studied with numerical simulation. The results show that the guessed initial probe size in ePIE can be determined by the corresponding boundary of 1% of maximum intensity of the simulated incident probe when the real incident beam size is difficult to determine exactly. When imaging a sample by PCDI, a better image can be reconstructed by choosing the number of scanning points as more than 7×7 and a scanning overlap ratio as larger than 70%. The amplitude distributions and incident spot phase also have significant effects on the reconstructed image quality.Cited