Color Space RGB to CMY and more?

How can I convert RGB to cyan magenta yellow colorspace as well as how can I identify in the image the exact shade of that color?

Hello Ashin -

There are a number of color-space-converter plugins out there
that can be used with ImageJ (but don’t ship with Fiji / ImageJ).

Here’s one: RGB to CMYK.

Here is the result of using it to convert the “Clown (14K)” to CMYK
(note that the “K” channel (black) is part of this), and saving as a
TIFF four-channel stack:

CMYK_clown.tif (1003.8 KB)

If you hover the mouse pointer over a pixel in the image, its value
(RGB value, if it’s a color image) will be displayed in the status bar
of Fiji’s main window.

You can also click on the “Pixel Inspection Tool” in the toolbar of
Fiji’s main window, and then click on the pixel of interest in your
image.

Thanks, mm

How do I show all the shades of each pixels in a given freehand area?

is there one for fiji because that’s the program I am trying to use

Hello Ashin -

I’m not sure what you are asking.

The color-space-converter plugin I linked to is for Fiji.

It doesn’t ship with Fiji, but it works with Fiji. You just have to
install it (by downloading the class file and placing it in Fiji’s
plugins directory). That’s how I created the CMYK stack I
posted.

Thanks, mm

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Is there a way to get the pixel inspector to show all the data in a freehand selection? Like if I draw a circle then all the shades in that circle I drew

Hello Ashin -

I don’t believe that the Pixel Inspection Tool (or other built-in
tool) will do this.

If you’re comfortable writing a macro or script, you can do it easily
enough that way.

If you want to use an IJM macro, the functions to look at would be
Roi.getCoordinates() and getPixel().

Thanks, mm

what is an IJM macro? I don really have any background in coding or in Image J so I am having a hard time with this haha

Hello Ashin -

Fiji / ImageJ is primarily a gui-based, interactive tool. It has,
however, the nice feature that you can program it in a number
of ways, either to automate repetitive tasks, or to implement
algorithms or other features that aren’t built into it.

Here is some documentation for the ImageJ Macro Language.
IJM was written specifically for ImageJ so it “knows” some
things about it. You can also get a head start on writing some
IJM macros (but probably not write them completely) by using
the Macro Recorder (Plugins > Macros > Record...).

However, IJM is less full-featured than some general-purpose
scripting languages. I generally prefer jython (python) for scripting
ImageJ. Here is some documentation for Jython Scripting.

The built-in functionality of ImageJ plus the ability to write scripts
(and java plugins) does make the ImageJ platform quite powerful.

If you’re relatively new to programming and ImageJ, you should
probably start with some tutorials or toy scripts, rather than jump
right into a real project.

Thanks, mm