Banner PresencePLUS P4 COLOR Series - Manual (Page 34)

Red, Green, Blue (RGB)
Red, Green, and Blue (RGB) is a representation of additive color space where red, green and blue are combined to
create other colors. This is the primary method for showing color on monitors and televisions.
The RGB color space is represented as a cube with the three primary colors whose axes are perpendicular to each other.
Black is the absence of all primary colors; that is, the intensity of all three primary colors is zero [0,0,0]. White is the
presence of of all primary colors; that is the intensity of all three primary colors is 255 -- [255,255,255].
A color value is specified with three numbers between 0 - 255, each representing Red, Green and Blue. For example,
the particular green shown above is [80,200,130].
Note: Typically, with a Color Vision sensor, none of the primary colors will be specified at either end of the
Intensity range (0 or 255). The sensor has an optimum Intensity range and the predominant primary color will
typically be around 200, and the other primary colors will be adjusted accordingly so that they do not fall out of
this optimum Intensity range.
Hue, Saturation, and Intensity (HSI)
One way to look at color is not in terms of red, green, and blue, but as hue, saturation, and intensity (HSI). We generally
do not see things as quantities of primary colors mixed in certain proportions. Rather, we see things as colors, or hues,
that either are " washed-out" or vivid. This means having low or high saturation, respectively.
Hue, saturation, and intensity, then, are three dimensions that provide a representation of color space that is closer to
human perception of color dynamics. "Colors" are defined as H, S, and I ratios are represented as a cone. The cone
shape has one central axis representing intensity. Along this axis are all the gray values, with black at the pointed end
of the cone and white at its base. The greater the distance along this line from the pointed end, or origin, the brighter
or higher the intensity.
4.6.2 Setting up a Color Inspection
To set up a color inspection, you need to calibrate the color imager for existing lighting conditions.
Auto Exposure
In order to ensure that the image is bright enough to perform accurate color sensing when setting up a color inspection,
the ROI should be placed over the color of interest:
1. Draw an ROI over the color in which you are interested.
2. Click the Start button.
Banner Engineering Corp. Minneapolis, MN USA 34
2/2010 Setup