[libcamera-devel] [PATCH v4 1/6] libcamera: properties: Define pixel array properties

Niklas Söderlund niklas.soderlund at ragnatech.se
Wed Apr 8 00:54:40 CEST 2020


Hi Jacopo,

Thanks for your great effort in defining properties!

On 2020-03-26 15:59:22 +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 | 155 ++++++++++++++++++++++++++++++++
>  1 file changed, 155 insertions(+)
> 
> diff --git a/src/libcamera/property_ids.yaml b/src/libcamera/property_ids.yaml
> index ce627fa042ba..ea9d363fdef8 100644
> --- a/src/libcamera/property_ids.yaml
> +++ b/src/libcamera/property_ids.yaml
> @@ -386,4 +386,159 @@ controls:
>                                |                    |
>                                |                    |
>                                +--------------------+
> +
> +  - PixelArraySize:
> +      type: float
> +      size: [2]
> +      description: |
> +        The physical sizes of the pixel array (width and height), in
> +        millimeters.
> +
> +  - PixelArray:
> +      type: int32_t
> +      size: [2]
> +      description: |
> +        The camera sensor pixel array vertical and horizontal sizes, in pixels.
> +
> +        The property describes a rectangle with its top-left corner in position
> +        (0, 0) and width and height described by the first and second values
> +        of this property.
> +
> +        The PixelArray property defines the rectangle that includes all possible
> +        rectangles defined by the ActiveAreas property, and describes the full
> +        pixel array, including non-active pixels, black level calibration
> +        pixels etc.
> +
> +  - ActiveAreas:
> +      type: int32_t
> +      size: [4 x n]
> +      description: |
> +        The camera sensor active pixel area rectangles, represented as
> +        rectangles contained in the one described by the PixelArrays property.

s/PixelArrays/PixelArray/

Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>

> +
> +        This property describes an arbitrary number of overlapping rectangles,
> +        representing the active pixel portions of the camera sensor pixel array.
> +
> +        Each rectangle is defined by its displacement from pixel (0, 0) of
> +        the rectangle described by the PixelArray property, a width and an
> +        height.
> +
> +        Each rectangle described by this property represents the maximum image
> +        size that the camera module can produce for a given image resolution.
> +
> +        Example 1.
> +        A sensor which only produces images in the 4:3 image resolution will
> +        report a single ActiveArea rectangle, from which all other image formats
> +        are obtained by either cropping the field-of-view and/or applying pixel
> +        sub-sampling techniques such as pixel skipping or binning.
> +
> +                        PixelArray(0)
> +                    /-----------------/
> +                      x1          x2
> +            (0,0)-> +-o------------o-+  /
> +                 y1 o +------------+ |  |
> +                    | |////////////| |  |
> +                    | |////////////| |  | PixelArray(1)
> +                    | |////////////| |  |
> +                 y2 o +------------+ |  |
> +                    +----------------+  /
> +
> +        The property reports a single rectangle
> +
> +                 ActiveArea = (x1, y1, (x2 - x1), (y2 - y1))
> +
> +        Example 2
> +        A camera sensor which can produce images in different native
> +        resolutions, will report several overlapping rectangle, one for each
> +        natively supported resolution, ordered from the tallest to the shortest
> +        one.
> +
> +                        PixelArray(0)
> +                    /-----------------/
> +                     x1  x2    x3  x4
> +            (0,0)-> +o---o------o---o+  /
> +                 y1 |    +------+    |  |
> +                    |    |//////|    |  |
> +                 y2 o+---+------+---+|  |
> +                    ||///|//////|///||  | PixelArray(1)
> +                 y3 o+---+------+---+|  |
> +                    |    |//////|    |  |
> +                 y4 |    +------+    |  |
> +                    +----+------+----+  /
> +
> +        The property reports two rectangles
> +
> +                PixelArray = ( (x2, y1, (x3 - x2), (y4 - 1),
> +                               (x1, y2, (x4 - x1), (y3 - y2))
> +
> +        The first rectangle describes the maximum field-of-view of all image
> +        formats in the 4:3 resolutions, while the second one describes the
> +        maximum field of view for all image formats in the 16:9 resolutions.
> +
> +  - 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 represents the arrangement of color filters
> +        in the top-left 2x2 pixel square.
> +
> +        For 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 filter arrangement is represented by the BGGR value, which
> +        correspond to the pixel readout sequence in line interleaved mode.
> +
> +      enum:
> +        - name: BayerFilterRGGB
> +          value: 0
> +          description: |
> +            Color filter array displacement is Red-Green/Green-Blue
> +
> +        - name: BayerFilterGRBG
> +          value: 1
> +          description: |
> +            Color filter array displacement is Green-Red/Blue-Green
> +
> +        - name: BayerFilterGBRG
> +          value: 2
> +          description: |
> +            Color filter array displacement is Green-Blue/Red-Green
> +
> +        - name: BayerFilterBGGR
> +          value: 3
> +          description: |
> +            Color filter array displacement is Blue-Green/Green-Red
> +
> +        - name: BayerFilterNonStandard
> +          value: 4
> +          description: |
> +            The pixel array color filter does not use the standard Bayer RGB
> +            color model
> +
> +  - ISOSensitivityRange:
> +      type: int32_t
> +      size: [2]
> +      description: |
> +        The range of supported ISO sensitivities, as documented by the
> +        ISO 12232:2006 (or later) standard.
> +
>  ...
> -- 
> 2.25.1
> 
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-- 
Regards,
Niklas Söderlund


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