Setting threshold levels tricky with float images

Create a float image containing nothing but 0's, 0.1's, 0.2's, and 0.3's. (For instance maybe as 3 filled rects).

Adjust threshold. Threshold min and max say 0.1 and 0.2. Adjust to 0.1 and 0.3. See that the 0.1 pixels are not included in threshold. If you print out min/max inside Threshold plugin you see that min is calced as 0.1000001 or something. The text in the field says 0.1 but its a little bigger. And thus the 0.1 pixels fall outside the threshold.

In addition you can type 0.1 in min field and tab to next field. Now 0.1 pixels are part of threshold. But then clicking on +/- arrows of min does not change the value. Somehow the bounds checking code determines it is out of bounds and fails completely. You can only get unstuck by entering in text field something greater than 0.1000001 and less than max.

Migrated-From: http://trac.imagej.net/ticket/1759

Start by reproducing the float-image case described in the issue with the Threshold plugin: values 0, 0.1, 0.2, and 0.3, then test both typed bounds and the min-field arrows. Trace the plugin's threshold parsing and bounds checking. Done means 0.1 is included when entered as 0.1 and the arrows continue to adjust the value correctly.

Written by the indexing model from the issue text.