NekoCWD/libcamera
NekoCWD/libcamera
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages 7 Wiki Activity Actions

ipa: ipu3: awb: Set a threshold for the green saturation

Browse source 
We can have a saturation ratio per cell, giving the percentage of pixels
over a threshold within a cell where 100% is set to 0xff.

The parameter structure 'ipu3_uapi_awb_config_s' contains four fields to
set the threshold, one per channel.
The blue field is also used to configure the ImgU and make it calculate
the saturation ratio or not.

Set a green value saturated when it is more than 230 (90% of the maximum
value 255, coded as 8191). As this is the only channel used for AGC,
there is no need to apply it to the other ones.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
This commit is contained in:
Jean-Michel Hautbois 2021-09-30 11:05:16 +02:00
parent f407027451
commit 59687683a1
2 changed files with 22 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

27
src/ipa/ipu3/algorithms/awb.cpp
View file

@ -328,14 +328,29 @@ void Awb::process(IPAContext &context, const ipu3_uapi_stats_3a *stats)
context.frameContext.awb.gains.red = asyncResults_.redGain;
}
constexpr uint16_t Awb::threshold(float value)
{
/* AWB thresholds are in the range [0, 8191] */
return value * 8191;
}
void Awb::prepare(IPAContext &context, ipu3_uapi_params *params)
{
params->acc_param.awb.config.rgbs_thr_gr = 8191;
params->acc_param.awb.config.rgbs_thr_r = 8191;
params->acc_param.awb.config.rgbs_thr_gb = 8191;
params->acc_param.awb.config.rgbs_thr_b = IPU3_UAPI_AWB_RGBS_THR_B_INCL_SAT
| IPU3_UAPI_AWB_RGBS_THR_B_EN
| 8191;
/*
* Green saturation thresholds are reduced because we are using the
* green channel only in the exposure computation.
*/
params->acc_param.awb.config.rgbs_thr_r = threshold(1.0);
params->acc_param.awb.config.rgbs_thr_gr = threshold(0.9);
params->acc_param.awb.config.rgbs_thr_gb = threshold(0.9);
params->acc_param.awb.config.rgbs_thr_b = threshold(1.0);
/*
* Enable saturation inclusion on thr_b for ImgU to update the
* ipu3_uapi_awb_set_item->sat_ratio field.
*/
params->acc_param.awb.config.rgbs_thr_b |= IPU3_UAPI_AWB_RGBS_THR_B_INCL_SAT |
IPU3_UAPI_AWB_RGBS_THR_B_EN;
const ipu3_uapi_grid_config &grid = context.configuration.grid.bdsGrid;