libcamera  v0.0.0
Supporting cameras in Linux since 2019
awb.h
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1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2 /*
3  * Copyright (C) 2021, Ideas On Board
4  *
5  * awb.h - IPU3 AWB control algorithm
6  */
7 
8 #pragma once
9 
10 #include <vector>
11 
12 #include <linux/intel-ipu3.h>
13 
14 #include <libcamera/geometry.h>
15 
16 #include "algorithm.h"
17 
18 namespace libcamera {
19 
20 namespace ipa::ipu3::algorithms {
21 
22 /* Region size for the statistics generation algorithm */
23 static constexpr uint32_t kAwbStatsSizeX = 16;
24 static constexpr uint32_t kAwbStatsSizeY = 12;
25 
26 struct Accumulator {
27  unsigned int counted;
28  struct {
29  uint64_t red;
30  uint64_t green;
31  uint64_t blue;
32  } sum;
33 };
34 
35 class Awb : public Algorithm
36 {
37 public:
38  Awb();
39  ~Awb();
40 
41  int configure(IPAContext &context, const IPAConfigInfo &configInfo) override;
42  void prepare(IPAContext &context, ipu3_uapi_params *params) override;
43  void process(IPAContext &context, IPAFrameContext *frameContext,
44  const ipu3_uapi_stats_3a *stats) override;
45 
46 private:
47  /* \todo Make these structs available to all the ISPs ? */
48  struct RGB {
49  RGB(double _R = 0, double _G = 0, double _B = 0)
50  : R(_R), G(_G), B(_B)
51  {
52  }
53  double R, G, B;
54  RGB &operator+=(RGB const &other)
55  {
56  R += other.R, G += other.G, B += other.B;
57  return *this;
58  }
59  };
60 
61  struct AwbStatus {
62  double temperatureK;
63  double redGain;
64  double greenGain;
65  double blueGain;
66  };
67 
68 private:
69  void calculateWBGains(const ipu3_uapi_stats_3a *stats);
70  void generateZones();
71  void generateAwbStats(const ipu3_uapi_stats_3a *stats);
72  void clearAwbStats();
73  void awbGreyWorld();
74  uint32_t estimateCCT(double red, double green, double blue);
75  static constexpr uint16_t threshold(float value);
76  static constexpr uint16_t gainValue(double gain);
77 
78  std::vector<RGB> zones_;
79  Accumulator awbStats_[kAwbStatsSizeX * kAwbStatsSizeY];
80  AwbStatus asyncResults_;
81 
82  uint32_t stride_;
83  uint32_t cellsPerZoneX_;
84  uint32_t cellsPerZoneY_;
85  uint32_t cellsPerZoneThreshold_;
86 };
87 
88 } /* namespace ipa::ipu3::algorithms */
89 
90 } /* namespace libcamera*/
The base class for all IPA algorithms.
Definition: algorithm.h:22
A Grey world white balance correction algorithm.
Definition: awb.h:36
int configure(IPAContext &context, const IPAConfigInfo &configInfo) override
Configure the Algorithm given an IPAConfigInfo.
Definition: awb.cpp:199
void process(IPAContext &context, IPAFrameContext *frameContext, const ipu3_uapi_stats_3a *stats) override
Process ISP statistics, and run algorithm operations.
Definition: awb.cpp:390
void prepare(IPAContext &context, ipu3_uapi_params *params) override
Fill the params buffer with ISP processing parameters for a frame.
Definition: awb.cpp:432
Data structures related to geometric objects.
Algorithm common interface.
@ RGB
Sensor is not Bayer; output has 3 16-bit values for each pixel, instead of just 1 16-bit value per pi...
Definition: property_ids.h:56
Top-level libcamera namespace.
Definition: backtrace.h:17
Global IPA context data shared between all algorithms.
Definition: ipa_context.h:92
Context for a frame.
Definition: ipa_context.h:79
RGB statistics for a given zone.
Definition: awb.h:26
unsigned int counted
Number of unsaturated cells used to calculate the sums.
Definition: awb.h:27
uint64_t red
Sum of the average red values of each unsaturated cell in the zone.
Definition: awb.h:29
struct libcamera::ipa::ipu3::algorithms::Accumulator::@2 sum
A structure containing the average red, green and blue sums.
uint64_t blue
Sum of the average blue values of each unsaturated cell in the zone.
Definition: awb.h:31
uint64_t green
Sum of the average green values of each unsaturated cell in the zone.
Definition: awb.h:30