Obtaining X-Y coordinates from an image

[Ammar]

Using ImageJ, I need ImageJ to output the X, Y coordinates of this membrane. There has to be some way of doing this since when you scroll around the membrane, the ImageJ taskbar shows the x coordinate, y coordinate, and its respective value as seen in the image below. Since the threshold value is 255, and any intensity beneath it is 0, therefore, the picture is already binary. Is there any function that will allow me to obtain all of the X-Y coordinates instead of using my mouse to scroll all around the membrane and write the coordinates down manually?

It was already asked by this individual here:
http://n2.nabble.com/How-to-show-the-X-Y-coordinates-of-all-points-in-the-Freehand-Curve.-td637363.html
however, nobody replied.



Thank you very much in advance, Regards,

Ammar

[Robert Kirmse]

Hi Ammar

i have written a makro once which was able to trace
black lines in a binary image.
I can check on Monday if I still have the source somewhere.

Another way (maybe not the fanciest) but quick and dirty would be to just use the macro function of ImageJ and draw a 1x1 pixel mask. move this mask per macro function to every pixelcoordinate in the image and check if it is black.
if its black print the x,y coordinate via the measure command
to the result table.
in this way you will get all the black pixel, hence the membrane in your binary image.

All this is easyly accessible by the macro editor in imageJ
again it is maybe not the most fanciest approach but will do the trick.

If you don´t know how to work with macros I can maybe just write this quick and dirty macro for you. You have to wait till monday though because I am busy this weekend.

Cheers and good luck
Robert





-------------------------------------------
Robert Kirmse, PhD.
University of Colorado at Boulder
Dept. of Mol. Cell. and Dev. Biology (MCDB)
Boulder CO, 80309-0347

Tel: [phone]
Fax: [phone]
Email: [hidden email]
-------------------------------------------

[Ammar]

Robert Kirmse wrote

Hi Ammar

i have written a makro once which was able to trace
black lines in a binary image.
I can check on Monday if I still have the source somewhere.

Another way (maybe not the fanciest) but quick and dirty would be to just use the macro function of ImageJ and draw a 1x1 pixel mask. move this mask per macro function to every pixelcoordinate in the image and check if it is black.
if its black print the x,y coordinate via the measure command
to the result table.
in this way you will get all the black pixel, hence the membrane in your binary image.

All this is easyly accessible by the macro editor in imageJ
again it is maybe not the most fanciest approach but will do the trick.

If you don´t know how to work with macros I can maybe just write this quick and dirty macro for you. You have to wait till monday though because I am busy this weekend.

Cheers and good luck
Robert





-------------------------------------------
Robert Kirmse, PhD.
University of Colorado at Boulder
Dept. of Mol. Cell. and Dev. Biology (MCDB)
Boulder CO, 80309-0347

Tel: [phone]
Fax: [phone]
Email: [e-mail]
-------------------------------------------

Thank you very much Robert for the offer, but I received a message earlier from Rasband Wayne which provided me everything I needed. Here it is:

Rasband Wayne wrote

Ammar,

1. Convert to binary using Process>Binary>Convert to Binary
2. Click inside membrane with the wand tool to trace the inside
   edge, or outside and to the left to trace the outside edge
3. Save the xy coordinates as a spreadsheet compatible
   tab-delimited text file using File>Save as>XY Coordinates

Many thanks to you all for helping me out with my research. Best wishes,

Ammar

[Sandie]

Robert,

Could you post the macro I would be really interested in seeing it. I have an image that does not have good contrast so I would like to find something that could help adjust the theshold and also be able to detact the boundary of the feature so I could get the x,y coordinates of the object.

Also is there a way to overlay x,y coordinates from Excel over an image to compare data taken from a Keyence 2D profiler?

Sandie