DNA measurement and Calibration curve in gel

Hello, i´m newcomer in imageJ. I´v been looking for tutorials that explain how to use imageJ for DNA measurement, but only had found some tutorials not very goods. Can anyone tell me about a guide or something that help me make a calibration curve for DNA measurement?

You might try this links:

Gel Analysis:

https://imagej.nih.gov/ij/docs/guide/146-30.html#sub:Calibrate

https://imagej.nih.gov/ij/docs/examples/calibration/

http://imagejdocu.tudor.lu/doku.php?id=video:analysis:gel_quantification_analysis

http://www.lukemiller.org/journal/2007/08/quantifying-western-blots-without.html

https://lukemiller.org/index.php/2010/11/analyzing-gels-and-western-blots-with-image-j/

Dot Blot Analysis:

https://theolb.readthedocs.io/en/latest/imaging/dot-blot-analysis-with-imagej.html

http://image.bio.methods.free.fr/ij/ijmacro/dotblot/text/dotblotdoc.html

Thank you very much.