ScanImage 2018 : Galvo-Galvo Image Appears Chopped Up

In running a Galvo/Galvo system with an NI 6115 card, using FOCUS, the image appears "chopped", whereas it looks like the upper and lower halves of the channel window were being updated out of sync.

It is most obvious when panning around a sample (otherwise your eye doesn't pick it up). 

Can this be prevented?


This is actually a feature, not a bug.

Since galvo/galvo scanning is slow, we implemented a feature called 'striping'.

We update a frame stripe by stripe, where one stripe is composed of multiple lines.

This ensures you see the data as soon as it is acquired and you don't have to wait to the end of the frame.


You can configure this feature by manually adding the following lines to the %%LinScan section of the Machine Data File to overwrite the default values:

stripingEnable = true;         % enables/disables striping display
stripingMaxRate = 10;         % [Hz] determines the maximum display update rate for striping


Usually the image would be chopped up into about 5 stripes, depending upon on your rate (e.g. sample rate is high, you might only get 2 stripes. This is based on stripingMaxRate.

This might look a bit odd on the display.


You can try to disable striping altogether or you can modify the stripingMaxRate to see more/less stripes.

However, don't increase beyond 20Hz; this might result in performance issues.


Useful ScanImage Links:

  1. Machine Data File
  2. Linear Scanning Striping Display