GIMP tools - BDA

GIMP 58
a) Contrast = 0 b) Contrast = 127 c) Contrast = -127
Threshold
This tool transforms the active layer into a monochrome image, i.e. it transforms a
colour image into a black-and-white image. A black-and-white photo does not fall into
this category as it always has shades of grey. To adjust settings, use the command
ColorsThreshold . In the dialog box you can use the slider and small black and
white triangular buttons.
Triangular buttons (A) control the field shown in the histogram. They adjust the size of
the selection and at the same time the composition of your image.
In a new image, pixels within the threshold range will be white, and others will be black.
This tool is rarely used on colour images. However, it is used to improve a black-andwhite
image, for example, a scanned text. It can also clear a mono image.