FITS Image Orientation

Image Cursor


The Image Cursor is a permanent tracking cursor available in an image display window, which is normally accessed through the CImageView class. The cursor is described by its rectangle extent, as a CRect, and its center position in pixel coordinates.

The Image Cursor is used for locating centroid positions, measuring region statistics, and defining the limits of column, row, and radial profile plots. As shown in the figure below, the Image Cursor is different from the Mouse Cursor, or "pointer" of the user interface. Note that the rectangle form of the Image Cursor (shown below) has a small central crosshair, and that both are shown in blue.

There is only one Image Cursor for each Image Window. Therefore, if an image set is opened by the window, the same Image Cursor is used for all members of the set. For example, if you use the Image Cursor to define the region to be cropped, and the Process Image Set flag is enabled, then all members of the image set will be cropped to the same region marked by the Image Cursor.

Properties of the Image Cursor

The Image Cursor has the following properties (see the Mira User's Guide for more detail).

Image Cursor Style

The image cursor can be set to any of the styles described in the table below.

Image Cursor Styles

Index

Style

0

Rectangle

The size and center position may be set.

1

Crosshair

The size and center position may be set.

2

Lines

The lines extend to the edges of the image. The position may be set.

3

Off

The image cursor is not visible.

Image Cursor Coordinates

The Image cursor position and edges are defined in terms of image pixel coordinates. Therefore, if you magnify the image, the Image Cursor coordinates remain correct at the level of subpixel precision, independent of the way the image is displayed.

Related Topics

CImageView, CRect