Point
Measurements Point
Measurements
The Point Measurement tool measures a
collection of point coordinates and values on an image. In addition
to reporting the pixel value, or "intensity", the pixel coordinates
are reported in both (column,row) and world coordinates
if the image has a world coordinate calibration. The coordinates
are marked using the mouse crosshair or may be precision centroid
coordinates computed near the clicked point. This command is like
the Centroid
measurement affiliated with the Image Cursor except this command operates from
a toolbar and the the points are persistent until you leave the
Points mode by closing the toolbar. This command allows many points
to be drawn on the image whereas the centroid marks only one point
at a time . Results are reported in the Points Measurement Pane. The
toolbar opens in Marking Mode with the top button active. Marker
properties are set in the Marker Properties dialog opened from the 
button on the Points toolbar. Points may also be
measured using the CMeasurePoints class in the Pro Script
Module. See theMira Pro x64 Script User's Guide.
To activate the Point Measurements
toolbar, click on the Image Measurements
Toolbar or use Measure > Points command on the main
menu.
The following picture shows an Image Window with several points marked on the image. Notice the Point Measurements Toolbar docked on the left border of the Image Window.
The 3 points marked above created a
Points Measurement Pane where the results are listed.
Results can also be diverted to a top-level Report Window using the
option in the Marker Properties dialog opened using the 
toolbar button.
First, make sure Point Measurement command.
First, be sure the Drawing and Centroiding
properties are set as desired. To open the Marker Properties
dialog, click on the toolbar.
If Marking Mode is
not active, click the 
button on the
window toolbar (not the Image Measurements Toolbar).
Move the mouse pointer to each target point and click the left mouse button.
Repeat for each target point on the image.
To move an existing point, click 
on the Points toolbar to enter
Move mode, then drag a marker to a
new position and drop it there. To cause the centroids to be
updated after the move, check
Centroid after Move on
the Centroid Properties (Markers) page:
If centroiding is checked on the Centroid Properties (Markers) page, the marker will automatically centroid on near the point where it is dropped.
The results are reported in the Points measurement pane or window.
If points are no longer needed, click 
to enter Delete
mode and click on the points to remove them.
To track marked points through an image set,
click 
on the toolbar. See the TIP below
regarding tracking the centroid.
To re-enter marking mode, click on the toolbar.
To disable all toolbar modes for Point
Measurements, click 
on the Image Bar or select
Disable Modes from the Image Context
Menu.
|
TIP |
Before tracking through an image set, be sure
|
Measurements are tabulated in the Points pane as shown above. Using this window, the measurements may be sorted, rearranged, saved to the clipboard or a file, etc.
If the image has a World Coordinate System ("WCS") calibration and the Centroid First Point box is checked in the Point Properties dialog , then (X,Y) is a centroid position computed from the centroid (column,row) position.
The items in the Report are described in the table below.
|
# |
The sequence number of the measurement. |
|
Image |
The name of the image that was measured |
|
Distance |
The distance in pixel units, or arcseconds if the image has a WCS calibration. |
|
Index |
By default, Mira fills this column with a sequential number which is the index of the point starting at 1. However, unlike the # column, which cannot be edited, this entry can be edited to give the point any identifier which then would be included in a saved or copied report. |
|
X |
The X coordinate of the point in world coordinates. If no world coordinate calibration exists, the value is the column position. |
|
Y |
The Y coordinate of the point in world coordinates. If no world coordinate calibration exists, the value is the row position.. |
|
Value |
The value of the pixel at (X,Y). |
|
Col |
The column coordinate of the point. |
|
Row |
The row coordinate of the point. |
Sub Pixel Coordinate Definition
Mira Pro x64 User's Guide, Copyright Ⓒ 2023 Mirametrics, Inc. All
Rights Reserved.
If checked, the centroid coordinates
will be computed for every member of the image set.