@@ -9,14 +9,19 @@
#include <algorithm>
#include <cmath>
+#include <optional>
#include <stdint.h>
#include <libcamera/base/log.h>
#include "simple/ipa_context.h"
+#include "control_ids.h"
+
namespace libcamera {
+LOG_DEFINE_CATEGORY(IPASoftLut)
+
namespace ipa::soft::algorithms {
int Lut::configure(IPAContext &context,
@@ -24,24 +29,46 @@ int Lut::configure(IPAContext &context,
{
/* Gamma value is fixed */
context.configuration.gamma = 0.5;
+ context.activeState.knobs.contrast = std::optional<double>();
updateGammaTable(context);
return 0;
}
+void Lut::queueRequest(typename Module::Context &context,
+ [[maybe_unused]] const uint32_t frame,
+ [[maybe_unused]] typename Module::FrameContext &frameContext,
+ const ControlList &controls)
+{
+ const auto &contrast = controls.get(controls::Contrast);
+ if (contrast.has_value()) {
+ context.activeState.knobs.contrast = contrast;
+ LOG(IPASoftLut, Debug) << "Setting contrast to " << contrast.value();
+ }
+}
+
void Lut::updateGammaTable(IPAContext &context)
{
auto &gammaTable = context.activeState.gamma.gammaTable;
- auto blackLevel = context.activeState.blc.level;
+ const auto blackLevel = context.activeState.blc.level;
const unsigned int blackIndex = blackLevel * gammaTable.size() / 256;
+ const auto contrast = context.activeState.knobs.contrast.value_or(1.0);
std::fill(gammaTable.begin(), gammaTable.begin() + blackIndex, 0);
const float divisor = gammaTable.size() - blackIndex - 1.0;
- for (unsigned int i = blackIndex; i < gammaTable.size(); i++)
- gammaTable[i] = UINT8_MAX * std::pow((i - blackIndex) / divisor,
- context.configuration.gamma);
+ for (unsigned int i = blackIndex; i < gammaTable.size(); i++) {
+ double normalized = (i - blackIndex) / divisor;
+ /* Apply simple S-curve */
+ if (normalized < 0.5)
+ normalized = 0.5 * std::pow(normalized / 0.5, contrast);
+ else
+ normalized = 1.0 - 0.5 * std::pow((1.0 - normalized) / 0.5, contrast);
+ gammaTable[i] = UINT8_MAX *
+ std::pow(normalized, context.configuration.gamma);
+ }
context.activeState.gamma.blackLevel = blackLevel;
+ context.activeState.gamma.contrast = contrast;
}
void Lut::prepare(IPAContext &context,
@@ -55,7 +82,8 @@ void Lut::prepare(IPAContext &context,
* observed, it's not permanently prone to minor fluctuations or
* rounding errors.
*/
- if (context.activeState.gamma.blackLevel != context.activeState.blc.level)
+ if (context.activeState.gamma.blackLevel != context.activeState.blc.level ||
+ context.activeState.gamma.contrast != context.activeState.knobs.contrast)
updateGammaTable(context);
auto &gains = context.activeState.gains;
@@ -20,6 +20,11 @@ public:
~Lut() = default;
int configure(IPAContext &context, const IPAConfigInfo &configInfo) override;
+ void queueRequest(typename Module::Context &context,
+ const uint32_t frame,
+ typename Module::FrameContext &frameContext,
+ const ControlList &controls)
+ override;
void prepare(IPAContext &context,
const uint32_t frame,
IPAFrameContext &frameContext,
@@ -8,8 +8,11 @@
#pragma once
#include <array>
+#include <optional>
#include <stdint.h>
+#include <libcamera/controls.h>
+
#include <libipa/fc_queue.h>
namespace libcamera {
@@ -44,7 +47,12 @@ struct IPAActiveState {
struct {
std::array<double, kGammaLookupSize> gammaTable;
uint8_t blackLevel;
+ double contrast;
} gamma;
+ struct {
+ /* 0..inf range, 1.0 = normal */
+ std::optional<double> contrast;
+ } knobs;
};
struct IPAFrameContext : public FrameContext {
Software ISP is currently fully automatic and doesn't allow image modifications by explicitly set control values. The user has no means to make the image looking better. This patch introduces support for contrast control, which can improve e.g. a flat looking image. Based on the provided contrast value with a range 0..infinity and 1.0 being the normal value, it applies a simple S-curve modification to the image. The contrast algorithm just handles the provided values, while the S-curve is applied in the gamma algorithm on the computed gamma curve whenever the contrast value changes. Since the algorithm is applied only on the lookup table already present, its overhead is negligible. This is a preparation patch without actually providing the control itself, which is done in the following patch. Signed-off-by: Milan Zamazal <mzamazal@redhat.com> --- src/ipa/simple/algorithms/lut.cpp | 38 +++++++++++++++++++++++++++---- src/ipa/simple/algorithms/lut.h | 5 ++++ src/ipa/simple/ipa_context.h | 8 +++++++ 3 files changed, 46 insertions(+), 5 deletions(-)