Area measurement tool
How to measure an area
Click several points to obtain an area (closed path).
Double-click the last point (point 7 in the example) to close the path.
- To undo a mouse click, press the Esc key.
- "Lasso" function: when using the path or area tools, the program will "sample" points when you press the Ctrl key whilst moving the mouse.
- While you are moving the mouse to the next position, lengths and angles are displayed in the status bar at the bottom of the Digimizer window.
The surface area, perimeter, length, width, centroid (geometric center), roundness, average intensity and hue are displayed in the Measurements list window (*).
- Roundness is defined by (4*PI*Area) / (Perimeter*Perimeter) and is a number between 0 and 1. Values closer to 1 indicate a more 'round' object. A circle has a roundness of 1.
- Definition of length and width:
Length is maximum distance between any 2 points on the object outline.
Width is the sum of the two maximum perpendicular distances between length-axis and any point on the object outline, on both sides of the length-axis.
When the option Show result after finalizing measurement is selected, then the area and perimeter are displayed in a small window next to the object.
Summary statistics for all areas, perimeters, lengths, widths and average intensities measured with the Area tool are displayed in the Statistics window.
*Only the parameters selected in the Measurements List Columns options box are displayed in the Measurements list window.
|When the lock is Open, the program returns to Select mode after performing a measurement using the Area tool. Close the lock when you need to perform several measurements with the same tool. See Lock tool.|