Description

Dynamically adjust a 16-bit digital camera input to 8-bit image.

typedef struct {
  u8 cameraIndex;
  u8 mode;
  u16 agHoldmax;
  u16 agHoldmin;
  u8 rowROIPct;
  u8 colROIPct;
  u8 highROIPct;
  u8 wideROIPct;
  u16 minAGRange;
  u8 agRate8;
  u8 minExp;
  u8 maxExp;
  u8 rejectDarkTail;
  u8 rejectBrightTail;
} SLASetDigitalCameraParameters_t;

AGC (Automatic Gain Control) is applied to the capture image before all other processing, with a smoothing filter time constant of ~1 second.
ROI (Region Of Interest) is used to indicate a part of image over which to perform autogain statistics . This ROI is defined as an offset from the relevant edge as a percentage of the full width / height of image.

To get the current values use SLAGetParameters_t. This will return a SLACurrentDigitalCameraParameters_t.

Note: Setting both `Autogain Max value' and `Autogain Min Value' to 0 will result in these parameters being ignored.

See also: SLASetADCParameters_t to set the brightiness (offset) and contrast (gain) used for AGC.; SLASetOverlayMode_t to enable histogram overlays for Capture & Display images.; EAN-Infrared-Temperature for more information.

Message ID 0x70

Byte Offset

Name

Description

4

cameraIndex

Camera index of digital camera (1500 = 2)

5

mode

Mode

Value	Description
0	Run high bit depth autogain (for G16 images)
1	Freeze high bit depth autogain at Autogain Min/Max
2	Run camera automatic exposure and gain 4000 only, New 3.1

6-7

agHoldmax

Autogain Max value (max value maps to 255 in 8 bit output

8-9

agHoldmin

Autogain Min Value (min value maps to 0 in 8 bit output)

10

rowROIPct

Row ROI for Autogain stats. Row Offset in % of image height (255=100%); Full image(default) = 0

11

colROIPct

Col ROI for Autogain stats. Col Offset in % of image width (255=100%); Full image(default) = 0

12

highROIPct

High ROI for Autogain stats. Height in % of image height (255=100%); Full image(default) = 255

13

wideROIPct

Wide ROI for Autogain stats. Width in % of image width (255=100%); Full image(default) = 255

14-15

minAGRange

Minimum spread of auto gain. 0 = does nothing, 200 = max - min scale range must be at least 200.
Prevents over-scaling of flat scenes. New 3.00

16

agRate8

Auto gain update rate. 0 = reset to 32, 1 = minimum rate, 255 = maximum rate, 32 = default. New 3.00
Use freeze Autogain to stop AGC updates

17

minExp

Ignored(default) = 0. IMX412: Minimum exposure or integration time 0 to 255. New 3.2

18

maxExp

Ignored(default) = 0. IMX412: Maximum exposure or integration time 0 to 255. New 3.2

19

rejectDarkTail

Reject or ignore the this percent/10 of the left/dark side of the histogram when calculating Autogain. 0 = reject none, 10 = reject 1.0%, 255 = reject 25.5%. Useful when there are a small number of very dark pixels in a scene. New 3.4

20

rejectBrightTail

Reject or ignore the this percent/10 of the right/bright side of the histogram when calculating Autogain. 0 = reject none, 10 = reject 1.0%, 255 = reject 25.5%. Useful when there are a small number of very bright pixels in a scene. New 3.4