How to quantify diseased leaf area in imageJ| measure lesion size on leaf | ImageJ area measurement

[@mohamedelgamal6333]

Many thanks, Alice for this great episode. I really appreciate it.

[@AliceritaE]

You're welcome, Mohamed!

[@ritasm5843]

This is a useful quantification technique, thank you

[@AliceritaE]

Thanks for your kind feedback

[@neftalycruzmireles3805]

Thank you very much, Alice! This tutorial is great. I have a quick question, in your infected leaves you can have different colours in your lesions. Is there a way to measure only the grey part of the lesion instead of the whole lesion?

[@AliceritaE]

Hi Neftaly, you will have to manually draw on that to measure the grey part. Alternatively, you can use the color threshold for selecting the grey part

[@neftalycruzmireles3805]

@@AliceritaE Ok! I’ll try that!! Thank you very much 😀

[@AliceritaE]

You're welcome 😊

[@MsDX1990]

Thanks Alice, for the wonderful tutorial. I am facing trouble as all my images are in black background. Could you suggest me a way out?

[@AliceritaE]

Hi, I don't have a sample image to experiment with. You can send one to me via email to check it out.

[@MsDX1990]

@@AliceritaE thank you! Please could you send me your email id

[@AliceritaE]

[e-mail]

[@leogaspar8529]

Great tutorial!

[@AliceritaE]

Cheers, Leo!

[@aliec4025]

Clear and informative

[@AliceritaE]

Thank you

[@arnaudthierry2001]

thanks.

[@AliceritaE]

You're welcome

[@oliverotieno692]

Which software do you use for this analysis?

[@AliceritaE]

Imagej software, similar to Fiji

[@AliceritaE]

Here is the download link imagej.nih.gov/ij/download.html

[@lokbahadurpun986]

Thank you for tutorial. But whenever I try to Adjust Autothreshold and Select "Try All", nothing is displayed as you have shown in this video. What might be the reason ?

[@AliceritaE]

If the file sample of big, it migth take some few minutes to process all of them. You should notice the processing bar slowing sliding on the imageJ window.

[@neftalycruzmireles3805]

Also, do you have to calibrate every single image you use?

[@AliceritaE]

If they have similar ruler, you can tick the global option when calibrating the first image

[@vishwanathiari]

Make a video on how to measure seed area, not just length/breadth

[@AliceritaE]

Hi, I can do that. Switch on your notification button. You will get alert when the video is online.

[@AliceritaE]

hi @Vishwanathiari, i have made the video on how measure seed area as requested. cheers!