Figure 2

Image Construction and Signal Processing in ScanImage A) Schematic depicting the algorithm of image creation in ScanImage. Pixels are constructed by summing the PMT voltage over the pixel time T_p. To achieve fast (i.e. realtime) refresh rates we break the acquisition of an image down into a set of stripes acquired and displayed in succession. The stripes are concatenated to form the entire image. B) Further details of image construction in ScanImage. a) Mirror position signal delivered by ScanImage (blue trace) and the actual mirror position (red trace) for two lines of acquisition (PMT voltage shown in gray). b) Definitions of acquisition parameters. The flyback (purple) and line delay (red) regions of the acquired PMT signal are discarded from final image data, which keeps only the fill fraction (blue) of the PMT voltage for image construction. Because the scan mirrors have inertia, their actual position lags the set position by ~7% of the scan period, which is corrected by the cusp delay (green). c) ScanImage retains the data acquired during the linear portions of the scan (blue) and discards the intervening data (red). d) Samples are summed to form the pixels in the final image.