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ipa: ipu3: awb: Correct the relevant zones proportion

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The algorithm uses the statistics of a cell only if there is not too
much saturated pixels in it. The grey world algorithm works fine when
there are a limited number of outliers.
Consider a valid zone to be at least 80% of unsaturated cells in it.
This value could very well be configurable, and make the algorithm more
or less tolerant.

While at it, implement it in a configure() call as it will not change
during execution, and cache the cellsPerZone values estimated with
std::round as we are using cmath.

Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
This commit is contained in:
Jean-Michel Hautbois 2021-09-15 20:00:48 +02:00
parent 195e6d0968
commit 3a240e56a8
2 changed files with 28 additions and 9 deletions
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32
src/ipa/ipu3/algorithms/awb.cpp
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@ -17,7 +17,6 @@ namespace ipa::ipu3::algorithms {
LOG_DEFINE_CATEGORY(IPU3Awb)
static constexpr uint32_t kMinZonesCounted = 16;
static constexpr uint32_t kMinGreenLevelInZone = 32;
/**
@ -173,6 +172,24 @@ Awb::Awb()
Awb::~Awb() = default;
int Awb::configure(IPAContext &context,
[[maybe_unused]] const IPAConfigInfo &configInfo)
{
const ipu3_uapi_grid_config &grid = context.configuration.grid.bdsGrid;
cellsPerZoneX_ = std::round(grid.width / static_cast<double>(kAwbStatsSizeX));
cellsPerZoneY_ = std::round(grid.height / static_cast<double>(kAwbStatsSizeY));
/*
* Configure the minimum proportion of cells counted within a zone
* for it to be relevant for the grey world algorithm.
* \todo This proportion could be configured.
*/
cellsPerZoneThreshold_ = cellsPerZoneX_ * cellsPerZoneY_ * 80 / 100;
return 0;
}
/**
* The function estimates the correlated color temperature using
* from RGB color space input.
@ -209,7 +226,7 @@ void Awb::generateZones(std::vector<RGB> &zones)
for (unsigned int i = 0; i < kAwbStatsSizeX * kAwbStatsSizeY; i++) {
RGB zone;
double counted = awbStats_[i].counted;
if (counted >= kMinZonesCounted) {
if (counted >= cellsPerZoneThreshold_) {
zone.G = awbStats_[i].sum.green / counted;
if (zone.G >= kMinGreenLevelInZone) {
zone.R = awbStats_[i].sum.red / counted;
@ -224,19 +241,16 @@ void Awb::generateZones(std::vector<RGB> &zones)
void Awb::generateAwbStats(const ipu3_uapi_stats_3a *stats,
const ipu3_uapi_grid_config &grid)
{
uint32_t cellsPerZoneX = round(grid.width / static_cast<double>(kAwbStatsSizeX));
uint32_t cellsPerZoneY = round(grid.height / static_cast<double>(kAwbStatsSizeY));
/*
* Generate a (kAwbStatsSizeX x kAwbStatsSizeY) array from the IPU3 grid which is
* (grid.width x grid.height).
*/
for (unsigned int cellY = 0; cellY < kAwbStatsSizeY * cellsPerZoneY; cellY++) {
for (unsigned int cellX = 0; cellX < kAwbStatsSizeX * cellsPerZoneX; cellX++) {
for (unsigned int cellY = 0; cellY < kAwbStatsSizeY * cellsPerZoneY_; cellY++) {
for (unsigned int cellX = 0; cellX < kAwbStatsSizeX * cellsPerZoneX_; cellX++) {
uint32_t cellPosition = (cellY * grid.width + cellX)
* sizeof(Ipu3AwbCell);
uint32_t zoneX = cellX / cellsPerZoneX;
uint32_t zoneY = cellY / cellsPerZoneY;
uint32_t zoneX = cellX / cellsPerZoneX_;
uint32_t zoneY = cellY / cellsPerZoneY_;
uint32_t awbZonePosition = zoneY * kAwbStatsSizeX + zoneX;