|Revision $Revision: 1.42 $
The Measure Tool is used to gain knowledge about pixel distances
in your working image. By clicking and holding the mouse button,
you can determine the angle and number of pixels between the
point of click and where the mouse pointer is located. The
information is displayed on the status bar or can also be
displayed in the Info Window.
When you pass the mouse pointer over the end point it turns to a
move pointer. Then if you click you can resume the measure.
Informations are displayed in the status bar, at the
bottom of the Image window. The status bar shows a pair of
numbers. The first number is the distance between the
origine point and the mouse pointer. Mostly the measure
unit is shown as Pixel. The second number is
the angle in every quadrant, from 0° to 90°.
You can call the Measure Tool in the following
order, from the image-menu:
You can also access to it by clicking the tool icon:
Holding down the Ctrl key puts the tool
into constrained straight line mode. The orientation of the
line is constrained to the nearest multiple of 15 degrees.
Holding down the Shift allows to start a new
measure from the pointed point without deleting the previous
measure. Angle is measured from the previous line. Mouse pointer
is accompanied by a “+” sign. So, you can
measure an angle
Ctrl key pressed and click on an end point
creates a horizontal guide.
Alt key and click on an end point should
create a vertical guide...
key combination and click on an end point creates a vertical and
a horizontal guides.
key combination and click on a measure line allows to move the
There is only one available option for the Measure Tool.
Use Info Window
This option will display an Info Window dialog that details
the measure tool results. The results are more complete
on the status bar.
You can't measure surfaces directly, but you can use the
Histogram that gives you
the number of pixels in a selection.