The white area on the left shows basic info on the array.
The square labeled as "Region of Interest" shows the selected size to be read. All coordinates are refred to the lower left corner, which has coordinate (1,1)
xstart: starting column
xsize: amount of columns
ystart: starting row
ysize: amount of rows
The selected ROI would be then:
Note that this is an indicator only. The actual control is the slide bar on the bottom. You can handle the bar or the yellow digital indicator directly. Here you define the size.
The "ReadTime" indicator shows the estimated readout time for the ROI selected. This value depends on the pixel read time as well as the time for skipping the undesired area