Omron F400 - INTRODUCTION Introduction Manual page 42

In colorgray filter, color image will be converted into gray image using hue and saturation, but lightness isn't
considered during conversion.
The density of gray image after conversion depends on the point on hue/ saturation plane of color image.
Density of colorgray image
= Saturation of measured color - (Hue of registered color - Hue of measured color)
(Ex.) Registered color: blue
Light blue
Select registered color out of 256 hues. Color bar displayed left side of a screen indicates hue.
Highest chroma colors in each hue are lined up on the color bar.
So blue must be selected on the color bar when light blue is to be registered.
Colorgray filter in color filter mode
Low
High
Saturation
Hue/saturation plane
Registered color
Blue
Red
Hue
As measured color is as close as registered color
and high chroma, it will be white in gray image.
Though hue is registered color, it will be gray in
gray image because of low saturation.
As measured color is as far as registered color, it
will be black in gray image though high
saturation.
See next page for the setting of color gray filter.
41