You can display an ROI in its own window if you can get the ROI Descriptor. The ROI Descriptor is a specific data cluster that IMAQ uses to carry the position location for an ROI. It is available as an output on several IMAQ VIs, including IMAQ ConstructROI, IMAQ WindGetROI, IMAQ MaskToROI, and any VI in the Functions»Vision and Motion»Vision Utilities»Region of Interest»Region of Interest Conversion sub-palette. If using Vision Acquisition Software 2009 or later, you will have access to the IMAQ Extract Tetragon VI. As seen below, the IMAQ Extract Tetragon VI takes the ROI Descriptor as a direct input and extracts the image within the area defined by the ROI Descriptor. The IMAQ WindDraw VI then takes this image and displays it in a separate image window.
If you are using a version of Vision Acquisition Software prior to 2009, there are a couple additional steps that you'll need to complete to display the ROI in a separate window. First you need to unbundle the ROI Descriptor cluster to get the Contours array. If you index this array, you can get a cluster which contains the Coordinates array. These coordinates describe the rectangular location for the ROI. If you use these coordinates and the IMAQ Extract VI, you can create a new image that contains only the region of the first image contained in the specified coordinates (which is the ROI). You can display this new image in its own window by using the IMAQ WindDraw VI.
Both of these methods can only be used with rectangular ROI selections. If you would like to display an ROI that isn't rectangular you can use the IMAQ WindDraw VI in conjunction with the ExtractFreeshapeROI.vi example discussed above.