The black level offset subtracted in AWB is wrong. It assumes that the
stats contain sums of the individual colour pixels. But they actually
contain sums of the colour channels of larger "superpixels" consisting
of the individual colour pixels. Each of the RGB colour values and the
computed luminosity (a histogram entry) are added once to the stats per
such a superpixel. This means the offset computed from the black level
and the number of pixels should be used as it is, not divided.
The patch fixes the subtracted offset. Since the evaluation is the same
for all the three colours now, the individual class variables are
replaced with a single RGB variable.
Fixes: 4e13c6f55b ("Honor black level in AWB")
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Robert Mader <robert.mader@collabora.com>
Tested-by: Robert Mader <robert.mader@collabora.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Generating statistics for every single frame is not really necessary.
However a roundtrip through ipa_->processStats() still need to be done
every frame, even if there are no stats to make the IPA generate metadata
for every frame.
Add a valid flag to the statistics struct to let the IPA know when there
are no statistics for the frame being processed and modify the IPA to
only generate metadata for frames without valid statistics.
This is a preparation patch for skipping statistics generation for some
frames.
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>
Tested-by: Milan Zamazal <mzamazal@redhat.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Hans de Goede <hansg@kernel.org>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Source files in libcamera start by a comment block header, which
includes the file name and a one-line description of the file contents.
While the latter is useful to get a quick overview of the file contents
at a glance, the former is mostly a source of inconvenience. The name in
the comments can easily get out of sync with the file name when files
are renamed, and copy & paste during development have often lead to
incorrect names being used to start with.
Readers of the source code are expected to know which file they're
looking it. Drop the file name from the header comment block.
The change was generated with the following script:
----------------------------------------
dirs="include/libcamera src test utils"
declare -rA patterns=(
['c']=' \* '
['cpp']=' \* '
['h']=' \* '
['py']='# '
['sh']='# '
)
for ext in ${!patterns[@]} ; do
files=$(for dir in $dirs ; do find $dir -name "*.${ext}" ; done)
pattern=${patterns[${ext}]}
for file in $files ; do
name=$(basename ${file})
sed -i "s/^\(${pattern}\)${name} - /\1/" "$file"
done
done
----------------------------------------
This misses several files that are out of sync with the comment block
header. Those will be addressed separately and manually.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Black may not be represented as 0 pixel value for given hardware, it may
be higher. If this is not compensated then various problems may occur
such as low contrast or suboptimal exposure.
The black pixel value can be either retrieved from a tuning file for the
given hardware, or automatically on the fly. The former is the right
and correct method, while the latter can be used when a tuning file is
not available for the given hardware. Since there is currently no
support for tuning files in software ISP, the automatic, hardware
independent way, is always used. Support for tuning files should be
added in future but it will require more work than this patch.
The patch looks at the image histogram and assumes that black starts
when pixel values start occurring on the left. A certain amount of the
darkest pixels is ignored; it doesn't matter whether they represent
various kinds of noise or are real, they are better to omit in any case
to make the image looking better. It also doesn't matter whether the
darkest pixels occur around the supposed black level or are spread
between 0 and the black level, the difference is not important.
An arbitrary threshold of 2% darkest pixels is applied; there is no
magic about that value.
The patch assumes that the black values for different colors are the
same and doesn't attempt any other non-primitive enhancements. It
cannot completely replace tuning files and simplicity, while providing
visible benefit, is its goal. Anything more sophisticated is left for
future patches.
A possible cheap enhancement, if needed, could be setting exposure +
gain to minimum values temporarily, before setting the black level. In
theory, the black level should be fixed but it may not be reached in all
images. For this reason, the patch updates black level only if the
observed value is lower than the current one; it should be never
increased.
The purpose of the patch is to compensate for hardware properties.
General image contrast enhancements are out of scope of this patch.
Stats are still gathered as an uncorrected histogram, to avoid any
confusion and to represent the raw image data. Exposure must be
determined after the black level correction -- it has no influence on
the sub-black area and must be correct after applying the black level
correction. The granularity of the histogram is increased from 16 to 64
to provide a better precision (there is no theory behind either of those
numbers).
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Add a CPU based SwStats implementation for SoftwareISP / SoftIPA use.
This implementation offers a configure function + functions to gather
statistics on a line by line basis. This allows CPU based software
debayering to call into interleave debayering and statistics gathering
on a line by line basis while the input data is still hot in the cache.
This implementation also allows specifying a window over which to gather
statistics instead of processing the whole frame.
Doxygen documentation by Dennis Bonke.
Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> # sc8280xp Lenovo x13s
Tested-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>
Co-developed-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Co-developed-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Co-developed-by: Dennis Bonke <admin@dennisbonke.com>
Signed-off-by: Dennis Bonke <admin@dennisbonke.com>
Co-developed-by: Marttico <g.martti@gmail.com>
Signed-off-by: Marttico <g.martti@gmail.com>
Co-developed-by: Toon Langendam <t.langendam@gmail.com>
Signed-off-by: Toon Langendam <t.langendam@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
