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Message-ID:  <[log in to unmask]>
Date:         Wed, 15 May 2002 16:40:31 -0400
Reply-To:     ImageJ Interest Group <[log in to unmask]>
Sender:       ImageJ Interest Group <[log in to unmask]>
From:         Wayne Rasband <[log in to unmask]>
Subject:      Re: Threshold...
In-Reply-To:  <[log in to unmask]>

On Wednesday, May 15, 2002, at 07:15 AM, Gary Chinga wrote:

>          Hi,
>
>         I am just wondering how to binarise an image by applying a
> predefined threshold value.
>
>                 IJ.setThreshold(minThreshold, maxThreshold);
>
>         yields the image with the thresholded areas in red, but I want
> to
> binarise this image into black and white. Which command do I need to
> use?

The Process->Threshold command in ImageJ 1.28e or later converts an
image to binary using the threshold levels set by the Adjust->Threshold
tool. It does automatic thresholding if no levels are set. In a plugin
you can convert to binary using predefined levels using

         IJ.setThreshold(minThreshold, maxThreshold);
         IJ.run("Threshold");


>         I also tried to use the adjust--> threshold... in the imagej
> menu
> but it doesnt seem to work with 32 bit greyscale stacks, the threshold
> is
> given only for the first slice.

You need to first convert the stack to 8-bits.

-wayne

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