I can think of a few ways to do this, but they all involve writing Java code. I don’t know if a simple method using either the GUI or a macro.
My leading candidate is to compute the width of the “non-black” pixels as a function of angle. From this you can find the maximal area bounding box. I did this sort of analysis 50 years ago - it’s not hard. It’s possible that fitting an ellipse to the non-black region might do the trick. Here I would worry that the head might be too circular. Note that this has little to do with finding the septum, but instead relies on the general shape and symmetry of the head. It’s interesting enough that I might be convinced to create a first cut of a Java plugin to do this. Please contact me off-list if you are interested. It looks like a one-day project. Perhaps someone more well versed in InageJ macros can figure out a way to do this without a Java plugin. —- Kenneth Sloan (von meinem iPhone13 gesendet) On Sat, Jan 25, 2025 at 11:06 Benn, Douglas K <[email protected]> wrote: > [cid:91093e05-79a0-456b-8ffd-a236158abe85] > Good morning, > > Can anybody please suggest a method using ImageJ macros to segment the > nasal septum to form a line whose orientation can be used to rotate the > axial slice so that the septum is at 90 degrees to the top image line 0? > > The attached axial CT slice of the face has a clockwise rotation of about > 4 degrees. I know how rotate the image counter clockwise to correct this > but cannot figure out how to extract a line for the septum. > > Thank you for your help. > > Douglas > > > > > Dr Douglas K Benn DDS, PhD, Dipl. Dental Radiology (Royal College of > Radiologists, England) > Professor of Radiology (Retired), Creighton University Dental School. > Professor Emeritus, University of Florida. > > > Residence: > Dr Douglas K Benn DDS, PhD, Dipl. Dental Radiology (Royal College of > Radiologists, England) > Oral and Maxillofacial Radiologist > Apartado 189-4013 > 20501 Atenas, Alajuela, > Costa Rica > > +506 2446 9310 > Cell +506 710 37977 > [email protected] > www.ReadCTs.com<http://www.ReadCTs.com> > > > Confidentiality Notice: > > This e-mail is intended only for the person or entity to which it is > addressed and may contain information that is privileged, confidential or > otherwise protected from disclosure. Dissemination, distribution or > copying of this e-mail or the information herein by anyone other than the > intended recipient, or an employee or agent responsible for delivering the > message to the intended recipient, is protected. If you have received > this e-mail in error, please contact the sender and destroy the original > message and all copies. > > > > -- > ImageJ mailing list: http://imagej.nih.gov/ij/list.html > -- ImageJ mailing list: http://imagej.nih.gov/ij/list.html
