Epson Moverio Pro BT-2000 Developer's Manual page 96

Remarks

PreviewCallback cannot guarantee the actual time of image acquisition. If there

are a high volume of calculations being performed in onPreviewFrame, and these
are not completed by the time of the next image data acquisition, the next image
data will be corrupted. We recommend acquiring image data through a
sub-thread.
You can use the following three APIs as the API that registers the callback method.
MOVERIO Pro Developer's Guide (Rev.1.4)
90