[libcamera-devel] [RFC 4/7] libcamera: properties: Define pixel array properties
Niklas Söderlund
niklas.soderlund at ragnatech.se
Wed Jan 15 21:14:55 CET 2020
Hi Jacopo,
Thanks for your effort writing this up, great work!
On 2019-12-18 15:49:58 +0100, Jacopo Mondi wrote:
> Add definition of pixel array related properties.
>
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
> src/libcamera/property_ids.yaml | 177 ++++++++++++++++++++++++++++++++
> 1 file changed, 177 insertions(+)
>
> diff --git a/src/libcamera/property_ids.yaml b/src/libcamera/property_ids.yaml
> index 811c300c6b0a..9e2333cb7206 100644
> --- a/src/libcamera/property_ids.yaml
> +++ b/src/libcamera/property_ids.yaml
> @@ -31,4 +31,181 @@ controls:
> Camera mounting rotation expressed as counterclockwise rotation degrees
> towards the axis perpendicular to the sensor surface and directed away
> from it
> +
> + - PixelArraySize:
> + type: float
> + compound: true
> + description: |
> + The physical sizes of the pixel array (width and height), in
> + millimeters.
> +
> + - PixelArrayBounds:
> + type: int32_t
> + compound: true
> + description: |
> + The camera sensor pixel array bounding rectangle vertical and
> + horizontal sizes.
> +
> + For image sensors with a rectangular pixel array the sizes described by
> + this property are the same as the PixelAreaSize property size.
> +
> + For image sensors with more complex pixel array displacements (such as
> + cross-shaped pixel arrays, non symmetrical pixel arrays etc) this
> + property represents the bounding rectangle in which all pixel array
> + dimensions are inscribed into.
> +
> + In example, the bounding rectangle sizes for image sensor with a
> + cross-shaped pixel array is described as
> +
> +
> + PixelArrayBound(0) = width
> + /-----------------/
> +
> + (0,0)-> +----+------+----+ /
> + | |//////| | |
> + +----+//////+----+ |
> + |////////////////| | PixelArrayBound(1) = height
> + +----+//////+----+ |
> + | |//////| | |
> + +----+------+----+ /
> + |
> + -> Cross-shaped pixel area
> +
> + - PixelArrays:
> + type: int32_t
> + compound: true
> + description: |
> + The sensor pixel array rectangles, relative to the rectangle described
> + by the PixelArrayBounds property.
> +
> + This property describes an arbitrary number of (likely overlapping)
> + rectangles, representing the pixel array areas the sensor is composed
> + of.
> +
> + Each rectangle is defined by its displacement from pixel (0, 0) of
> + the bounding rectangle described by the PixelArrayBound property.
> +
> + For image sensors with a rectangular pixel array, a single rectangle
> + is required. For sensors with more complex pixel array displacements
> + multiple rectangles shall be specified, ordered from the tallest to the
> + shorter one.
> +
> + For each rectangle, this property reports the full pixel array size,
> + including non-active pixels, black level calibration pixels etc.
> +
> + In example, a simple sensor with a rectangular pixel array is described
> + as
> +
> + PixelArrayBound(0) = width
> + /-----------------/
> + x1 x2
> + (0,0)-> +-o------------o-+ /
> + y1 o +------------+ | |
> + | |////////////| | |
> + | |////////////| | | PixelArrayBound(1) = height
> + | |////////////| | |
> + y2 o +------------+ | |
> + +----------------+ /
> +
> + PixelArray = (x1, y1, (x2 - x1), (y2 - y1))
> +
> + A more complex sensor, with a cross shaped pixel array displacement
> + is described with 2 rectangles, with the vertical rectangle
> + described first
> +
> + PixelArrayBound(0) = width
> + /-----------------/
> + x1 x2 x3 x4 W
> + (0,0)-> +o---o------o---o+ /
> + | |//////| | |
> + y1 o+---+------+---+| |
> + ||///|//////|///|| | PixelArrayBound(1) = height
> + y2 o+---+------+---+| |
> + | |//////| | |
> + H +----+------+----+ /
> +
> +
> + PixelArray = ( (x2, 0, (x3 - x2), H),
> + (x1, y1, (x4 - x1), (y2 - y1))
> +
> + - ActiveAreaSize:
> + type: int32_t
> + compound: true
> + description: |
> + The sensor active pixel area sizes, represented as rectangles
> + inscribed in the ones described by the PixelArrays property.
> +
> + One ActiveAreaSize rectangle per each rectangle described in the
> + PixelArrays property is required. As a consequence, the two properties
> + shall transport the same number of elements.
> +
> + The ActiveAreaSize rectangles represent the maximum image sizes the
> + sensor can produce.
This paragraph is the only thing preventing me from attaching my tag to
this series. It's not clear to me what the difference between
PixelArrays and ActiveAreaSize is.
> +
> + - BayerFilterArrangement:
> + type: int32_t
> + description: |
> + The pixel array color filter displacement.
> +
> + This property describes the arrangement and readout sequence of the
> + three RGB color components of the sensor's Bayer Color Filter Array
> + (CFA).
> +
> + Color filters are usually displaced in line-alternating fashion on the
> + sensor pixel array. In example, one line might be composed of Red-Green
> + while the successive is composed of Blue-Green color information.
> +
> + The value of this property represent the arrangement of color filters
> + in the top-left 2x2 pixel square.
> +
> + In example, for a sensor with the following color filter displacement
> +
> + (0, 0) (max-col)
> + +---+ +--------------...---+
> + |B|G|<---|B|G|B|G|B|G|B|...B|G|
> + |G|R|<---|G|R|G|R|G|R|G|...G|R|
> + +---+ |B|G|B|G|B|G|B|...B|G|
> + ... ..
> + ... ..
> + |G|R|G|R|G|R|G|...G|R|
> + |B|G|B|G|B|G|B|...B|G| (max-lines)
> + +--------------...---+
> +
> + The filer arrangement is represented by the BGGR value, which correspond
> + to the pixel readout sequence in line interleaved mode.
> +
> + enum:
> + - BayerFilterRGGB:
> + value: 0
> + description: |
> + Color filter array displacement is Red-Green/Green-Blue
> +
> + - BayerFilterGRBG:
> + value: 1
> + description: |
> + Color filter array displacement is Green-Red/Blue-Green
> +
> + - BayerFilterGBRG:
> + value: 2
> + description: |
> + Color filter array displacement is Green-Blue/Red-Green
> +
> + - BayerFilterBGGR:
> + value: 3
> + description: |
> + Color filter array displacement is Blue-Green/Green-Red
> +
> + - BayerFilterNonStandard:
> + value: 4
> + description: |
> + The pixel array color filter does not use the standard Bayer RGB
> + color model
> +
> + - ISOSensitivityRange:
> + type: int32_t
> + compound: true
> + description: |
> + The range of supported ISO sensitivities, as documented by the
> + ISO 12232:2006 standard
> +
> ...
> --
> 2.24.0
>
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--
Regards,
Niklas Söderlund
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