Changing an image by using Argb

I am using the TImage class to process images in ROOT. I want to make a greyscale image black and white by choosing a threshold value and applying this to the image. Can I alter the pointer acquired from GetArgbArray() and then apply this to the image?

If not, how do I obtain and change the ImageData used by SetImage?

May be the example $ROOTSYS/tutorials/image/trans_graph.C can help you ?

I could not find trans_graph.c in my root directory or in the tutorial pages on Could you post a link or attach it to a reply?


May be you have an old ROOT version. See here:

I think that will help.

My ROOT version is five months old by the way. I see that this tutorial was added three months ago, which will explain why I didn’t know about it.

Thank you very much. :slight_smile: