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Replace Red with Magenta

Replace Red with Magenta (ImageJ)
Author Johannes Schindelin
Maintainer Johannes Schindelin
Source on GitHub
Initial release 27/06/2011
Latest version 27/06/2011
Category Category:Plugins

This plugin converts all occurrences of red in a red/green image with magenta, effectively replacing it with a magenta/green merge.

Note: the plugin completely ignores the blue channel, and replaces it with a copy of the red channel.


Error creating thumbnail: Unable to save thumbnail to destination
Error creating thumbnail: Unable to save thumbnail to destination

Replace Red with Magenta (system clipboard)

Frequently all you want to do is to replace red by magenta in some images in a text document or a presentation. With this function, you only need to copy the image into the system clipboard in the other program, call this plugin in Fiji, and then you can paste the corrected image in the other program.


8% of the male population is red-green blind. If given the task to find two colors maximizing the number of people who cannot see the difference, red and green are a wise choice. Yet, still way too many figures in scientific publications show red/green merges.

At least magenta/green images help this situation. However, the only thing human eyes can quantify are numbers.

As a demonstration, call Fiji's File  › Open Samples  › Spirals and if you see a bright green and a bright yellow in the dominant spirals, you should look closer.

However, in the 21st century, one should always use proper Colocalization with scatter plots and statistics. It is too easy not to.