pixel selection

[Brian DeSanti]

Hi,

I am new to ImageJ. I have watch several tutorials and can not figure out how to select and measure a certain pixel range.

The picture is of corals that are alive and dead. The live corals are white and the dead corals are brown. I am interested in getting the area of the white corals and the area of all the corals. I have used the freestyle tool and roughly drawn around the corals and measured the pixels. I was looking for a more precise way that may grab only the pixels that I am looking for. Is there a plug in for this or something that may have not been shown in tutorials?

Thanks,
Brian

[Nathaniel Ryckman]

1) Use Image->Adjust->ColorThreshold. After selecting the coral that you are interested in based off of hue, saturation, etc., click "Apply".

2) Use Analyze->Analyze Particles

3) Select the Region of Interest (ROI) that you want to measure

4) Analyze->Measure

Hope that helps!

[Brian DeSanti]

Yes. That was very helpful.

Thank you,
Brian