LUT Colors & Text size

Greetings All,

I am very new to using ImageJ & ImageJ2 and need to try and figure out how to make, or modify an existing LUT. Currently using the ImageJ2 at the moment.

We generally have tiff and gel files that are 10,000 x 8,000 in size and I need to have a LUT that is perhaps similar to the Jet or Spectrum LUT’s but with a background that is white.

The other problem that I have is that we want to put labels on these images and about the only way that I have found to do it is with adding text from the toolbar while raising the Font-Size to a MAX of 200 which is still small text on the image for what we need.

Is there way to get a larger font size than 200?

Could it be changed in the code to perhaps 400 or more?

Any assistance would be greatly appreciated.
Cheers and have a great day.

Welcome to the forum, @LTC!

You can edit any LUT by running Image > Color > Edit LUT… (see the documentation) and set a single value to white, or invert the entire LUT via Image > Lookup Tables > Invert LUT.

I recommend using the mpl-viridis LUT in Fiji, as it is still interpretable even after an RGB image using this LUT is converted to grayscale.

The slider is limited to 200, but you can enter any value in the text field next to it, and it will be considered:


Thanks for replying and I have been able to really start to get the results that we are looking for with these adjustments.

Regarding the font size, I ad assumed that the slider size was the limiting font size but just now tested it based upon your suggestions and it works great.

Thanks again and have a great day,

Hello Again,

Sorry for the continuation of this thread, but when I use the “Fonts” editor and set up all of the correct parameters to display some test on the image, I am able to write the text in the textbox, but as soon as I move to a new location to add in another textbox, or do some other activity, the text disappears.

Basically, no text is being shown or saved on the image for some reason.

Any ideas on this?


After creating the text selection, you can:

  • draw it into the image (changing the pixels irreversibly) using Ctrl+D or Edit > Draw
  • add it as an overlay using Ctrl+B or Image > Overlay > Add Selection…

See the text tool documentation.

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