Thank you, it is in the analyse menu ? With line selections, the following parameters can be recorded: length, angle (straight lines only), mean, standard deviation, mode, min, max and bounding rectangle (v1.34l or later). The mean, standard deviation, etc. are calculated from the values of the pixels along the line.
To export the measurements as a tab-delimited text file, select File>Save As>Measurements from the ImageJ menu bar or File>Save As from the “Results” window menu bar. Copy the measurements to the clipboard by selecting Edit>Copy All from the “Results” window menu bar. You can also save measurements by right-clicking in the Results window and selecting Save As or Copy All from the popup menu. https://www.youtube.com/watch?v=xXE7MBiWJIc