| Message ID | 20240423182000.1527425-3-mzamazal@redhat.com |
|---|---|
| State | New |
| Headers | show |
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| Related | show |
Hi Milan, Thank you for the patch. On Tue, Apr 23, 2024 at 08:19:57PM +0200, Milan Zamazal wrote: > The white balance computation didn't consider black level. This is > wrong because then the computed ratios are off when they are computed > from the whole brightness range rather than the sensor range. > > This patch adjusts white balance computation for the black level. There > is no need to change white balance application in debayering as this is > already applied after black level correction. Makes sense. > Exposure computation already subtracts black level, no changes are > needed there. > > Signed-off-by: Milan Zamazal <mzamazal@redhat.com> > --- > src/ipa/simple/soft_simple.cpp | 43 ++++++++++++++++++++++++---------- > 1 file changed, 31 insertions(+), 12 deletions(-) > > diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp > index b9fb58b5..30956a19 100644 > --- a/src/ipa/simple/soft_simple.cpp > +++ b/src/ipa/simple/soft_simple.cpp > @@ -5,6 +5,8 @@ > * soft_simple.cpp - Simple Software Image Processing Algorithm module > */ > > +#include <numeric> > +#include <stdint.h> > #include <sys/mman.h> > > #include <linux/v4l2-controls.h> > @@ -240,28 +242,45 @@ void IPASoftSimple::stop() > > void IPASoftSimple::processStats(const ControlList &sensorControls) > { > + SwIspStats::Histogram histogram = stats_->yHistogram; > + if (ignoreUpdates_ > 0) > + blackLevel_.update(histogram); > + const uint8_t blackLevel = blackLevel_.get(); > + params_->blackLevel = blackLevel; > + > /* > * Calculate red and blue gains for AWB. > * Clamp max gain at 4.0, this also avoids 0 division. > */ > - if (stats_->sumR_ <= stats_->sumG_ / 4) > - params_->gainR = 1024; > - else > - params_->gainR = 256 * stats_->sumG_ / stats_->sumR_; > + { It's not that I dislike proper indentation, but maybe not just for the sake of it ? :-) Why do you enclose that block in curly braces, especially given that you remove extra indentation in the next patch ? A comment here to explain why you need to subtract the black level would be useful. > + const uint64_t nPixels = std::accumulate( > + histogram.begin(), histogram.end(), 0); > + auto subtractBlackLevel = [blackLevel, nPixels]( > + uint64_t sum, uint64_t div) > + -> uint64_t { > + uint64_t reducedSum = sum - blackLevel * nPixels / div; Looks good so far. > + uint64_t spreadSum = reducedSum * 256 / (256 - blackLevel); I'm not sure about this. Why do you want to "spread" the sum ? > + return spreadSum; > + }; > + const uint64_t sumR = subtractBlackLevel(stats_->sumR_, 4); > + const uint64_t sumG = subtractBlackLevel(stats_->sumG_, 2); > + const uint64_t sumB = subtractBlackLevel(stats_->sumB_, 4); > + > + if (sumR <= sumG / 4) > + params_->gainR = 1024; > + else > + params_->gainR = 256 * sumG / sumR; > > - if (stats_->sumB_ <= stats_->sumG_ / 4) > - params_->gainB = 1024; > - else > - params_->gainB = 256 * stats_->sumG_ / stats_->sumB_; > + if (sumB <= sumG / 4) > + params_->gainB = 1024; > + else > + params_->gainB = 256 * sumG / sumB; > + } > > /* Green gain and gamma values are fixed */ > params_->gainG = 256; > params_->gamma = 0.5; > > - if (ignoreUpdates_ > 0) > - blackLevel_.update(stats_->yHistogram); > - params_->blackLevel = blackLevel_.get(); > - > setIspParams.emit(); > > /* \todo Switch to the libipa/algorithm.h API someday. */
Laurent Pinchart <laurent.pinchart@ideasonboard.com> writes: > Hi Milan, > > Thank you for the patch. Hi Laurent, thank you for the reviews. > On Tue, Apr 23, 2024 at 08:19:57PM +0200, Milan Zamazal wrote: >> The white balance computation didn't consider black level. This is >> wrong because then the computed ratios are off when they are computed >> from the whole brightness range rather than the sensor range. >> >> This patch adjusts white balance computation for the black level. There >> is no need to change white balance application in debayering as this is >> already applied after black level correction. > > Makes sense. > >> Exposure computation already subtracts black level, no changes are >> needed there. >> >> Signed-off-by: Milan Zamazal <mzamazal@redhat.com> >> --- >> src/ipa/simple/soft_simple.cpp | 43 ++++++++++++++++++++++++---------- >> 1 file changed, 31 insertions(+), 12 deletions(-) >> >> diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp >> index b9fb58b5..30956a19 100644 >> --- a/src/ipa/simple/soft_simple.cpp >> +++ b/src/ipa/simple/soft_simple.cpp >> @@ -5,6 +5,8 @@ >> * soft_simple.cpp - Simple Software Image Processing Algorithm module >> */ >> >> +#include <numeric> >> +#include <stdint.h> >> #include <sys/mman.h> >> >> #include <linux/v4l2-controls.h> >> @@ -240,28 +242,45 @@ void IPASoftSimple::stop() >> >> void IPASoftSimple::processStats(const ControlList &sensorControls) >> { >> + SwIspStats::Histogram histogram = stats_->yHistogram; >> + if (ignoreUpdates_ > 0) >> + blackLevel_.update(histogram); >> + const uint8_t blackLevel = blackLevel_.get(); >> + params_->blackLevel = blackLevel; >> + >> /* >> * Calculate red and blue gains for AWB. >> * Clamp max gain at 4.0, this also avoids 0 division. >> */ >> - if (stats_->sumR_ <= stats_->sumG_ / 4) >> - params_->gainR = 1024; >> - else >> - params_->gainR = 256 * stats_->sumG_ / stats_->sumR_; >> + { > > It's not that I dislike proper indentation, but maybe not just for the > sake of it ? :-) Why do you enclose that block in curly braces, > especially given that you remove extra indentation in the next patch ? This is to limit the scope of local variables to the relevant region (which is extended in the next patch). Functionally, it's just a matter of style so I can remove the braces. > A comment here to explain why you need to subtract the black level would > be useful. OK, will add one. >> + const uint64_t nPixels = std::accumulate( >> + histogram.begin(), histogram.end(), 0); >> + auto subtractBlackLevel = [blackLevel, nPixels]( >> + uint64_t sum, uint64_t div) >> + -> uint64_t { >> + uint64_t reducedSum = sum - blackLevel * nPixels / div; > > Looks good so far. > >> + uint64_t spreadSum = reducedSum * 256 / (256 - blackLevel); > > I'm not sure about this. Why do you want to "spread" the sum ? Right, the multiplication is meaningless here, I'll remove it. >> + return spreadSum; >> + }; >> + const uint64_t sumR = subtractBlackLevel(stats_->sumR_, 4); >> + const uint64_t sumG = subtractBlackLevel(stats_->sumG_, 2); >> + const uint64_t sumB = subtractBlackLevel(stats_->sumB_, 4); >> + >> + if (sumR <= sumG / 4) >> + params_->gainR = 1024; >> + else >> + params_->gainR = 256 * sumG / sumR; >> >> - if (stats_->sumB_ <= stats_->sumG_ / 4) >> - params_->gainB = 1024; >> - else >> - params_->gainB = 256 * stats_->sumG_ / stats_->sumB_; >> + if (sumB <= sumG / 4) >> + params_->gainB = 1024; >> + else >> + params_->gainB = 256 * sumG / sumB; >> + } >> >> /* Green gain and gamma values are fixed */ >> params_->gainG = 256; >> params_->gamma = 0.5; >> >> - if (ignoreUpdates_ > 0) >> - blackLevel_.update(stats_->yHistogram); >> - params_->blackLevel = blackLevel_.get(); >> - >> setIspParams.emit(); >> >> /* \todo Switch to the libipa/algorithm.h API someday. */
On Fri, Apr 26, 2024 at 12:37:31PM +0200, Milan Zamazal wrote: > Laurent Pinchart <laurent.pinchart@ideasonboard.com> writes: > > > Hi Milan, > > > > Thank you for the patch. > > Hi Laurent, > > thank you for the reviews. > > > On Tue, Apr 23, 2024 at 08:19:57PM +0200, Milan Zamazal wrote: > >> The white balance computation didn't consider black level. This is > >> wrong because then the computed ratios are off when they are computed > >> from the whole brightness range rather than the sensor range. > >> > >> This patch adjusts white balance computation for the black level. There > >> is no need to change white balance application in debayering as this is > >> already applied after black level correction. > > > > Makes sense. > > > >> Exposure computation already subtracts black level, no changes are > >> needed there. > >> > >> Signed-off-by: Milan Zamazal <mzamazal@redhat.com> > >> --- > >> src/ipa/simple/soft_simple.cpp | 43 ++++++++++++++++++++++++---------- > >> 1 file changed, 31 insertions(+), 12 deletions(-) > >> > >> diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp > >> index b9fb58b5..30956a19 100644 > >> --- a/src/ipa/simple/soft_simple.cpp > >> +++ b/src/ipa/simple/soft_simple.cpp > >> @@ -5,6 +5,8 @@ > >> * soft_simple.cpp - Simple Software Image Processing Algorithm module > >> */ > >> > >> +#include <numeric> > >> +#include <stdint.h> > >> #include <sys/mman.h> > >> > >> #include <linux/v4l2-controls.h> > >> @@ -240,28 +242,45 @@ void IPASoftSimple::stop() > >> > >> void IPASoftSimple::processStats(const ControlList &sensorControls) > >> { > >> + SwIspStats::Histogram histogram = stats_->yHistogram; > >> + if (ignoreUpdates_ > 0) > >> + blackLevel_.update(histogram); > >> + const uint8_t blackLevel = blackLevel_.get(); > >> + params_->blackLevel = blackLevel; > >> + > >> /* > >> * Calculate red and blue gains for AWB. > >> * Clamp max gain at 4.0, this also avoids 0 division. > >> */ > >> - if (stats_->sumR_ <= stats_->sumG_ / 4) > >> - params_->gainR = 1024; > >> - else > >> - params_->gainR = 256 * stats_->sumG_ / stats_->sumR_; > >> + { > > > > It's not that I dislike proper indentation, but maybe not just for the > > sake of it ? :-) Why do you enclose that block in curly braces, > > especially given that you remove extra indentation in the next patch ? > > This is to limit the scope of local variables to the relevant region (which is > extended in the next patch). The next patch removes the nested scope, so I don't really see why it's needed here. I'm fine restricing scope of variables when there's a technical reason to do so, for instance to use pattenrs RAII for locks. That doesn't seem to be the case here, and the code compiles fine without the nested scope. > Functionally, it's just a matter of style so I can > remove the braces. > > > A comment here to explain why you need to subtract the black level would > > be useful. > > OK, will add one. > > >> + const uint64_t nPixels = std::accumulate( > >> + histogram.begin(), histogram.end(), 0); > >> + auto subtractBlackLevel = [blackLevel, nPixels]( > >> + uint64_t sum, uint64_t div) > >> + -> uint64_t { > >> + uint64_t reducedSum = sum - blackLevel * nPixels / div; > > > > Looks good so far. > > > >> + uint64_t spreadSum = reducedSum * 256 / (256 - blackLevel); > > > > I'm not sure about this. Why do you want to "spread" the sum ? > > Right, the multiplication is meaningless here, I'll remove it. > > >> + return spreadSum; > >> + }; > >> + const uint64_t sumR = subtractBlackLevel(stats_->sumR_, 4); > >> + const uint64_t sumG = subtractBlackLevel(stats_->sumG_, 2); > >> + const uint64_t sumB = subtractBlackLevel(stats_->sumB_, 4); > >> + > >> + if (sumR <= sumG / 4) > >> + params_->gainR = 1024; > >> + else > >> + params_->gainR = 256 * sumG / sumR; > >> > >> - if (stats_->sumB_ <= stats_->sumG_ / 4) > >> - params_->gainB = 1024; > >> - else > >> - params_->gainB = 256 * stats_->sumG_ / stats_->sumB_; > >> + if (sumB <= sumG / 4) > >> + params_->gainB = 1024; > >> + else > >> + params_->gainB = 256 * sumG / sumB; > >> + } > >> > >> /* Green gain and gamma values are fixed */ > >> params_->gainG = 256; > >> params_->gamma = 0.5; > >> > >> - if (ignoreUpdates_ > 0) > >> - blackLevel_.update(stats_->yHistogram); > >> - params_->blackLevel = blackLevel_.get(); > >> - > >> setIspParams.emit(); > >> > >> /* \todo Switch to the libipa/algorithm.h API someday. */
diff --git a/src/ipa/simple/soft_simple.cpp b/src/ipa/simple/soft_simple.cpp index b9fb58b5..30956a19 100644 --- a/src/ipa/simple/soft_simple.cpp +++ b/src/ipa/simple/soft_simple.cpp @@ -5,6 +5,8 @@ * soft_simple.cpp - Simple Software Image Processing Algorithm module */ +#include <numeric> +#include <stdint.h> #include <sys/mman.h> #include <linux/v4l2-controls.h> @@ -240,28 +242,45 @@ void IPASoftSimple::stop() void IPASoftSimple::processStats(const ControlList &sensorControls) { + SwIspStats::Histogram histogram = stats_->yHistogram; + if (ignoreUpdates_ > 0) + blackLevel_.update(histogram); + const uint8_t blackLevel = blackLevel_.get(); + params_->blackLevel = blackLevel; + /* * Calculate red and blue gains for AWB. * Clamp max gain at 4.0, this also avoids 0 division. */ - if (stats_->sumR_ <= stats_->sumG_ / 4) - params_->gainR = 1024; - else - params_->gainR = 256 * stats_->sumG_ / stats_->sumR_; + { + const uint64_t nPixels = std::accumulate( + histogram.begin(), histogram.end(), 0); + auto subtractBlackLevel = [blackLevel, nPixels]( + uint64_t sum, uint64_t div) + -> uint64_t { + uint64_t reducedSum = sum - blackLevel * nPixels / div; + uint64_t spreadSum = reducedSum * 256 / (256 - blackLevel); + return spreadSum; + }; + const uint64_t sumR = subtractBlackLevel(stats_->sumR_, 4); + const uint64_t sumG = subtractBlackLevel(stats_->sumG_, 2); + const uint64_t sumB = subtractBlackLevel(stats_->sumB_, 4); + + if (sumR <= sumG / 4) + params_->gainR = 1024; + else + params_->gainR = 256 * sumG / sumR; - if (stats_->sumB_ <= stats_->sumG_ / 4) - params_->gainB = 1024; - else - params_->gainB = 256 * stats_->sumG_ / stats_->sumB_; + if (sumB <= sumG / 4) + params_->gainB = 1024; + else + params_->gainB = 256 * sumG / sumB; + } /* Green gain and gamma values are fixed */ params_->gainG = 256; params_->gamma = 0.5; - if (ignoreUpdates_ > 0) - blackLevel_.update(stats_->yHistogram); - params_->blackLevel = blackLevel_.get(); - setIspParams.emit(); /* \todo Switch to the libipa/algorithm.h API someday. */
The white balance computation didn't consider black level. This is wrong because then the computed ratios are off when they are computed from the whole brightness range rather than the sensor range. This patch adjusts white balance computation for the black level. There is no need to change white balance application in debayering as this is already applied after black level correction. Exposure computation already subtracts black level, no changes are needed there. Signed-off-by: Milan Zamazal <mzamazal@redhat.com> --- src/ipa/simple/soft_simple.cpp | 43 ++++++++++++++++++++++++---------- 1 file changed, 31 insertions(+), 12 deletions(-)