These examples show how changing the threshold values affect the rendering of the same image:

Red, Green & Blue with Black outline on White background

<FILE FILENAME="COMPASS.PNG" FILETYPE="PNG" />

Red, Green & Blue shown White

<FILE FILENAME="COMPASS.PNG" FILETYPE="PNG" MONOCHROME="25" />

Red shown Black, Green & Blue shown White

<FILE FILENAME="COMPASS.PNG" FILETYPE="PNG" MONOCHROME="50" />

Red & Green shown Black, Blue shown White

<FILE FILENAME="COMPASS.PNG" FILETYPE="PNG" MONOCHROME="100" />

Red, Green & Blue shown Black

<FILE FILENAME="COMPASS.PNG" FILETYPE="PNG" MONOCHROME="200" />