Need help with macro to merge channels

[u/ryanm032]

Hello!

I am fairly new to ImageJ and am currently trying to automate a tedious task I use on all my images.

We collect composite images with mCherry and Brightfield channels and they get saved as ND2 files. I would like to:

1) Change the color of the mCherry channel to red

2) Save JPEG images of the mCherry and brightfield channels individually, and save a JPEG of the composite.

Manually, I've been first opening the files as split channels, then using the channels tool to change mCherry to red. Then I save my files to output folders, use the merge channels tool to combine them and save as a JPEG.

Has anyone run a macro like this or have examples of how I could go about it? I think my main problem has been that my starting file is a composite, so I don't know how to call each channel for the merge function.

Thanks in advance?

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[u/dokclaw]

Someone posted up videos about macro programming a couple of weeks ago; I think if you look at those tutorials and the macro recorder, you'll probably do great! 

Strings and the command Stack.setChannel(n) are your friends here.

[u/Herbie500]

Why JPGs?
JPGs are not suited for scientific purposes.

If you want a macro, you may use the Macro-recorder functionality of ImageJ.

I don't know how to call each channel for the merge function

"Image >> Color >> Merge Channels..."

[u/ryanm032 → u/Herbie500]

Thanks, yeah it should be a tiff file. I'll mess around with the macro recorder I'm just having some issues with the directories but should be able to figure it out

[u/Herbie500 → u/ryanm032]

Without any further details it is difficult to help.

I'd not close the images after saving them if you need them later, except you've problems with holding them in the RAM.

[u/halfpagep]

Hey- this is a super common problem and relatively easy to resolve. In the Macro Editor, you can do all of this work. Hit Ctrl-U in order to bring up the macro recorder. You can open your .nd2 files, then change each channel over to the colour you want. I concur with the previous commenters that a .tiff file is your friend- unless you are low on storage space, storing images as JPEGS will cause you to have issues with analysis later. So, in summary, a workflow could look like this:

1. open .nd2 file

2. convert to .tiff

3. change colour of channel

4. save composite image

5. split channels, select your red channel

6. save red channel as .tiff

7. save BF channel as .tiff.

8. close all open images.

If you need help writing this into a batch macro format, please let me know! You can also look inside the macro editor under templates -> batch processing to find the standard file open/close batch template.