IRAF help page for package images.tv.iis, program blink

blink -- Blink frames in the image display

blink frame1 frame2 [frame3 [frame4]]

First frame in blink sequence.

Second frame in blink sequence.

Third frame in blink sequence.

Fourth frame in blink sequence.

Blink rate in seconds per frame. May be any fraction of a second.

Two or more frames are alternatedly displayed on the image display monitor ("stdimage") at a specified rate per frame.

To blink two frames:

cl> blink 1 2

To blink three frames at a rate of 2 seconds per frame:

cl> blink 3 1 2 rate=2

The blink rate is measured in software and, therefore, will not be exactly even in a time sharing environment.