Threshold

Don't go over...

The Threshold tool coverts an image to black and white based on a threshold value.

The Threshold tool.

Threshold level The level at which pixels are assigned to either black or white. You can use the Auto Level button to get an estimate based on the histogram of the image.

Invert Usually, values less than the Threshold Level are assigned to black, and values above are assigned to white. When this option is checked, this will be reversed, so that pixels below the Threshold Level become white and pixels above become black.

Threshold RGB channels Rather that produce a black and white image, this will produce a color image with a threshold applied to each color channel.