Color Adjustments - Basler ace acA640-90gm User Manual

8.5.4

Color Adjustments

The pixel values output from the sensor go through several transformation steps before they are
transmitted by the camera. During one step in the process, the pixel values wil be in the RGB (red,
green, blue) color space.
The camera's color adjustment feature lets you adjust hue and saturation for the primary and
secondary colors in the RGB color space. Each adjustment affects those colors in the image where
the adjusted primary or secondary color predominates. For example, the adjustment of red affects
the colors in the image with a predominant red component.
For the color adjustments to work properly, the white balance must be correct.
See Section 8.5.1 on
see Section 8.5.5 on
The RGB Color Space
The RGB color space includes light with the primary colors red, green, and blue and all of their
combinations. When red, green, and blue light are combined and when the intensities of R, G, and
B are allowed to vary independently between 0 % and 100 %, all colors within the RGB color space
can be formed. Combining colored light is referred to as additive mixing.
When two primary colors are mixed at equal intensities, the secondary colors will result. The mixing
of red and green light produces yellow light (Y), the mixing of green and blue light produces cyan
light (C), and the mixing of blue and red light produces magenta light (M).
When the three primary colors are mixed at maximum intensities, white will result. In the absence
of light, black will result.
The color space can be represented as a color cube (see Figure 74 on
colors R, G, B, the secondary colors C, M, Y, and black and white define the corners. All shades of
grey are represented by the line connecting the black and the white corner.
For ease of imagination, the color cube can be projected onto a plane (as shown in Figure 74) such
that a color hexagon is formed. The primary and secondary colors define the corners of the color
hexagon in an alternating fashion. The edges of the color hexagon represent the colors resulting
from mixing the primary and secondary colors. The center of the color hexagon represents all
shades of grey including black and white.
The representation of any arbitrary color of the RGB color space will lie within the color hexagon.
The color will be characterized by its hue and saturation:
Hue specifies the kind of coloration, for example, whether the color is red, yellow, orange etc.
Saturation expresses the colorfulness of a color. At maximum saturation, no shade of grey is
present. At minimum saturation, no "color" but only some shade of grey (including black and
white) is present.
Basler ace GigE
page 150 for more information about the white balance and
page 161 for a overall procedure for setting the
Color Creation and Enhancement
page 158) where the primary
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