5.5. Threshold Tool

With the Treshold tool you can make visible or invisible the pixels of the active layer or selection by their intensity values.

Activate Tool

The Threshold Tool can be called in the following order, from the image-menu: Tools/ Color Tools/Threshold .

Options

Threshold range

The Threshold tool provides a visual graph of the intensity value of the active layer or selection. You can set the threshold range either using the input boxes or clicking button 1 and dragging on the graph. It allows you to select a part of the image with some intensity from a background with another intensity. Pixels inside the range will be white, and the others will be black. Adjust the range to get the selection you want in white on black background. This method of extracting a selection is well explained in Grokking the Gimp.

Preview

The Preview toggle allows dynamic updating of the active layer or selection while changes are made to the intensity level.