To open the Point Preferences page, click
to open the dialog and select the
Points tab.
Points Preferences (Register)
The Point Preferences page is a member of the Point Preferences dialog. Use this page to setup the way centroid positions are measured for objects being marked. Some comments on a few of the less obvious parameters are given below.
To open the Point Preferences page, click
to open the dialog and select the
Points tab.
See these page descriptions:
Resampling Preferences
Background Preferences
Other parameters can be set for point tracking and drawing the markers. These are handled in the Marking Preferences dialog. The preferences for markers used in image registration are described below:
The Sample Radius defines the distance from the target point within which points are used to compute the centroid position. A reasonable starting point for choosing a value is 2 times the FWHM (note that FWHM is a diameter and this parameter is a radius).
The Tracking Radius is used when computing the centroid of an Image Set. This value defines the maximum offset distance Mira will search in the next image to lock onto a new centroid position.
The Track Centroids option controls the duplication of markers when the positions are "tracked" through an image set. If Track Centroids is checked, the positions are centroided in every image.
Centroid positions are computed using image data, not the screen display. Choose Positivepoints or Negative points based upon the type of object to measure rather than the palette or other image display attributes. For modern, inherently digital images, you will almost always choose Positive points. For scanned photographs, however, you may be working with a negative image and would choose the NegativePoints option.