Modifying the coordinate systemPhase MOSAIC

Coordinate system tools can be accessed using the Transform | Align menu item. These tools modify the current coordinate system that is overlayed on the pixel data.


LE Required

Transforming Surfaces and Images

Translate Origin will shift the center of the coordinate system to either the Centroid (surfaces only)centroid icon,  Data Center, Corner, or an Arbitrary point, which will bring up a dialog box for user-defined translation distances. The centroid of the data is defined to be the vector average of all of the valid data pixels - all of which have equal weight.
Rotate the coordinate system 90°ccw, 90°cw, 180°, or an Arbitrary amount which will ask the user for the rotation amount in degrees. Rotations refer to the coordinate system, so a positive angle rotates the coordinate system counter-clockwise which makes the pixel data apear to rotate clockwise.
Match allows the user to import the coordinate system from an existing File, or Fiducial Group(s) allows the user to fit a coordinate system so that the least-square error between a fiducial group in the current data and another fiducial group is minimized. The fiducial editor window on the right of the Match Fiducials dialog allows the user to manually enter fiducials or load fiducial groups from other files. The units of the groups to match may be changed using the Match Units list box below the editor. Highlighting corresponding groups on the left and right of the dialog allows a matching coordinate system to be calculated. The RMS error between the transformed fiducial coordinates and the target coordinates is displayed. To commit to the new coordinate system select the OK button.
Scale changes the coordinate system or pixel data scaling. Fiducial Distance scale distance button allows the user to define the X and Y scale using a known distance between any 2 fiducials. This feature can be used to upgrade the fundamental intrinsic unit from pixel widths to millimeters by choosing millimeter derived predefined units in the units pull-down box.

Pixel Size scales the pixel size by a specified scale factor. The aspect ratio of the pixel can be preserved using the Lock Aspect checkbox.

Height scales the pixel data by a specified scale factor.

Arbitrary allows the user to define X, Y, and Z scaling factors. X, Y, or Z scaling factors can be negative to allow for flipping or mirroring the coordinate system. The X and Y scaling can be specified independantly by deselecting the Lock Aspect checkbox.

See Also

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