Posted by
Brandon Hurr on
Jul 22, 2016; 3:15am
URL: http://imagej.273.s1.nabble.com/Help-for-a-new-user-to-analyze-percentage-of-certain-colored-pixels-in-digital-image-tp5016922p5016923.html
1. Yes
2. Look at color thresholding. Image -> Adjust -> Color Thresholding
Since you are doing color analysis, you need to be very careful with the
settings of your camera and your lighting. Taking the photos under
different white balance settings or different lights will affect your
thresholding.
I would segment for total plant area visible (red + green) and then find
red only and compute the difference in area.
The simplest way to create a macro would be to use the recorder. Do the
steps in pieces and use google to search past questions on this list and
stackoverflow.
Focus on image quality first and foremost, and then the analysis will
follow.
B
On Thu, Jul 21, 2016 at 7:51 PM, Emily Teng <
[hidden email]> wrote:
> Hi everyone,
> I am completely new to ImageJ. Just found out about it today and hoping it
> is exactly what I need for my research purposes. I am a PhD student.
>
> I need a method to analyze the percent of coloration of poinsettia plants
> over time. I plan to take digital photos of the top of the canopy over
> time and analyze those images. As I understand it, I could use ImageJ for
> this purpose correct?
>
> Taking for example, a red poinsettia - I would need the program to count
> all the pixels that are any shade of red (vs green) in the plant.
>
>
http://www.ecke.com/poinsettias/bractmeter/>
> That is what I'm trying to do. The professor who created that told me he
> had someone do programming to count the pixels. But I'm thinking ImageJ
> will be able to do this if I know how to use it?
>
> Can someone tell me
> 1. Can ImageJ do this?
> 2. If yes - Point me in the direction of how I should go about learning
> how to do this?
>
> Thank you in advance for any help and guidance.
>
> Emily
>
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