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CD40047_R04_allPIXA_User-Manual.docx 148
11.6 Brightness and contrast
These parameters describe the digital gaining and offset parameters for the camera. Brightness
and contrast adjustment takes place in step (3) of the digital image processing pipeline (section
4.6.1;
“Figure 10: Digital process of the allPIXA camera (block diagram) ”).
NOTE
If these parameters are used to adjust image brightness in a wide range to get
brighter images, this may degrade image quality.
First, use analog gaining to adjust brightness of the image (see sections 11.2.1
and 11.2.2). For instance, after adjusting analog gain and performing a shading
correction (it sets the values for white to 255), you can get the white slightly out
of the area of the image saturation from 255 to 245.
The internal processing is not limited up to 255@8bit. This means that after the
shading correction it is possible to additionally process higher values such as
300, which can be taken without loss into the visible area by using the
brightness and contrast control afterwards.
Use brightness and contrast
Name
Name Use brightness and contrast
Function Enables the digital gaining and contrast function in the camera.
Channels All
Unit
Bool
Dependency
None
Notes
Camera: Value: Function:
Lower limit
all 0 Off
Upper limit
all 1 On
Brightness
Name
Name Brightness
Function
Digital offset
Channels
Red; Green; Blue
Unit Integer
Linear
Dependency Only available if the Use Brightness and Contrast check box has been selected.
Notes
This value refers to 10-bit image data; in output image there are usually 8-bit image
data.
Camera: Value: Output image:
Lower limit
all -255 -64
Upper limit
all 255 64