Mark Centroid

Check this box to cause Mira to compute a precision centroid coordinate whenever you mark a template or target point. If not checked, then Mira will use the exact position you mark with the mouse.

Negative Points

Choose this option to compute the centroid position based on negative deviations below the background. Use this option when the images being measured are actually negatives (not positives displayed as negative; see Image Palettes and the Palette Properties dialog).

Positive Points

Choose this option to compute the centroid position based on positive deviations above the background. This is the typical case

Radius

Defines the radius, in pixels, from the target point within which pixel data are used to compute the centroid position. A reasonable starting point for choosing a value is 2 times the FWHM.

(Note: FWHM measures a diameter and this parameter is a radius).

Tracking

Defines the maximum distance, in pixels, from the current position that Mira will search in the next image to lock onto a new position. This is only used when tracking objects through an image set.

Track Centroids

Controls the duplication of markers when the positions are "tracked" through an image set. If this option is checked, the positions are centroided in every image.

Show Template

Click this button to display the master template in an Image window. If working with an image set, only the template for the current image is shown.

Show Samples

Click this button to display the template samples marked in the current image. The samples are shown as an image set in a new image window.