LQ-401CL
20
6.2.6 Black level
The setup level of the LQ-400CL is set at 8LSB in 4 x 8-bit output mode as the factory default setting
(32LSB for 4 x 10-bit output mode)
In order to adjust, the following commands are available.
BLM= 0 Master mode
BLM= 1 Individual mode
BL= 0 to 64
BLR= -64 to 63
BLB= -64 to 63
BLIR= -64 to 63
If the gain is set at Master mode:
Adjusting range Master(green) : 0LSB to 64LSB (16LSB)
Red
: -64(-16) LSB to +64(16) LSB
Blue
: -64(-16) LSB to +64(16) LSB
NIR
: -64(-16) LSB to +64(16) LSB
Figures in ( ) are for 8-bit output
If the gain is set at Individual mode:
Adjusting range Red
: 0LSB to 64(16) LSB
Green
: 0LSB to 64(16) LSB
Blue
: 0LSB to 64(16) LSB
NIR
: 0LSB to 64(16) LSB
Figures in ( ) are for 8-bit output
Note: Red, green, blue and NIR can be adjusted individually
6.2.7 PRNU (Pixel Response Non-Uniformity ) correction
PRNU (Pixel Response Non-Uniformity) is, as the name implies, a non-uniformity of the response of
each individual pixel. This means that for a fixed light level each pixel will have a slightly different
output level (response).
Fig.15 Conceptual drawing for PRNU correction (1)
To correct for PRNU, the camera’s internal correction circuit captures one or several lines of data
under non-saturated illuminated conditions which are not more than 80% of maximum (recommend
level is half of maximum), and the average across the line is calculated. Based on this average,
coefficients are then generated for each individual pixel. The coefficient has the function of
multiplying the pixel output with a factor greater or less than 1. These coefficients are stored in a
non-volatile memory, and are therefore maintained after power down.
Max
Min
Multiply
by
Factor > 1
Multiply
by
Factor < 1
Before correction: Non-uniform response from pixel to pixel
Average