1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
/* SPDX-License-Identifier: BSD-2-Clause */
/*
* Copyright (C) 2019, Raspberry Pi Ltd
*
* awb.h - AWB control algorithm
*/
#pragma once
#include <mutex>
#include <condition_variable>
#include <thread>
#include "../awb_algorithm.h"
#include "../pwl.h"
#include "../awb_status.h"
namespace RPiController {
/* Control algorithm to perform AWB calculations. */
struct AwbMode {
int read(const libcamera::YamlObject ¶ms);
double ctLo; /* low CT value for search */
double ctHi; /* high CT value for search */
};
struct AwbPrior {
int read(const libcamera::YamlObject ¶ms);
double lux; /* lux level */
Pwl prior; /* maps CT to prior log likelihood for this lux level */
};
struct AwbConfig {
AwbConfig() : defaultMode(nullptr) {}
int read(const libcamera::YamlObject ¶ms);
/* Only repeat the AWB calculation every "this many" frames */
uint16_t framePeriod;
/* number of initial frames for which speed taken as 1.0 (maximum) */
uint16_t startupFrames;
unsigned int convergenceFrames; /* approx number of frames to converge */
double speed; /* IIR filter speed applied to algorithm results */
bool fast; /* "fast" mode uses a 16x16 rather than 32x32 grid */
Pwl ctR; /* function maps CT to r (= R/G) */
Pwl ctB; /* function maps CT to b (= B/G) */
Pwl ctRInverse; /* inverse of ctR */
Pwl ctBInverse; /* inverse of ctB */
/* table of illuminant priors at different lux levels */
std::vector<AwbPrior> priors;
/* AWB "modes" (determines the search range) */
std::map<std::string, AwbMode> modes;
AwbMode *defaultMode; /* mode used if no mode selected */
/*
* minimum proportion of pixels counted within AWB region for it to be
* "useful"
*/
double minPixels;
/* minimum G value of those pixels, to be regarded a "useful" */
uint16_t minG;
/*
* number of AWB regions that must be "useful" in order to do the AWB
* calculation
*/
uint32_t minRegions;
/* clamp on colour error term (so as not to penalise non-grey excessively) */
double deltaLimit;
/* step size control in coarse search */
double coarseStep;
/* how far to wander off CT curve towards "more purple" */
double transversePos;
/* how far to wander off CT curve towards "more green" */
double transverseNeg;
/*
* red sensitivity ratio (set to canonical sensor's R/G divided by this
* sensor's R/G)
*/
double sensitivityR;
/*
* blue sensitivity ratio (set to canonical sensor's B/G divided by this
* sensor's B/G)
*/
double sensitivityB;
/* The whitepoint (which we normally "aim" for) can be moved. */
double whitepointR;
double whitepointB;
bool bayes; /* use Bayesian algorithm */
};
class Awb : public AwbAlgorithm
{
public:
Awb(Controller *controller = NULL);
~Awb();
char const *name() const override;
void initialise() override;
int read(const libcamera::YamlObject ¶ms) override;
unsigned int getConvergenceFrames() const override;
void setMode(std::string const &name) override;
void setManualGains(double manualR, double manualB) override;
void enableAuto() override;
void disableAuto() override;
void switchMode(CameraMode const &cameraMode, Metadata *metadata) override;
void prepare(Metadata *imageMetadata) override;
void process(StatisticsPtr &stats, Metadata *imageMetadata) override;
struct RGB {
RGB(double r = 0, double g = 0, double b = 0)
: R(r), G(g), B(b)
{
}
double R, G, B;
RGB &operator+=(RGB const &other)
{
R += other.R, G += other.G, B += other.B;
return *this;
}
};
private:
bool isAutoEnabled() const;
/* configuration is read-only, and available to both threads */
AwbConfig config_;
std::thread asyncThread_;
void asyncFunc(); /* asynchronous thread function */
std::mutex mutex_;
/* condvar for async thread to wait on */
std::condition_variable asyncSignal_;
/* condvar for synchronous thread to wait on */
std::condition_variable syncSignal_;
/* for sync thread to check if async thread finished (requires mutex) */
bool asyncFinished_;
/* for async thread to check if it's been told to run (requires mutex) */
bool asyncStart_;
/* for async thread to check if it's been told to quit (requires mutex) */
bool asyncAbort_;
/*
* The following are only for the synchronous thread to use:
* for sync thread to note its has asked async thread to run
*/
bool asyncStarted_;
/* counts up to framePeriod before restarting the async thread */
int framePhase_;
int frameCount_; /* counts up to startup_frames */
AwbStatus syncResults_;
AwbStatus prevSyncResults_;
std::string modeName_;
/*
* The following are for the asynchronous thread to use, though the main
* thread can set/reset them if the async thread is known to be idle:
*/
void restartAsync(StatisticsPtr &stats, double lux);
/* copy out the results from the async thread so that it can be restarted */
void fetchAsyncResults();
StatisticsPtr statistics_;
AwbMode *mode_;
double lux_;
AwbStatus asyncResults_;
void doAwb();
void awbBayes();
void awbGrey();
void prepareStats();
double computeDelta2Sum(double gainR, double gainB);
Pwl interpolatePrior();
double coarseSearch(Pwl const &prior);
void fineSearch(double &t, double &r, double &b, Pwl const &prior);
std::vector<RGB> zones_;
std::vector<Pwl::Point> points_;
/* manual r setting */
double manualR_;
/* manual b setting */
double manualB_;
};
static inline Awb::RGB operator+(Awb::RGB const &a, Awb::RGB const &b)
{
return Awb::RGB(a.R + b.R, a.G + b.G, a.B + b.B);
}
static inline Awb::RGB operator-(Awb::RGB const &a, Awb::RGB const &b)
{
return Awb::RGB(a.R - b.R, a.G - b.G, a.B - b.B);
}
static inline Awb::RGB operator*(double d, Awb::RGB const &rgb)
{
return Awb::RGB(d * rgb.R, d * rgb.G, d * rgb.B);
}
static inline Awb::RGB operator*(Awb::RGB const &rgb, double d)
{
return d * rgb;
}
} /* namespace RPiController */
|
