On 07/16/2016 02:38 PM, Laurent Pinchart wrote: > Hi Hans, > > On Saturday 16 Jul 2016 10:19:29 Hans Verkuil wrote: >> On 07/15/2016 08:11 PM, Laurent Pinchart wrote: >>> On Friday 15 Jul 2016 18:13:15 Ricardo Ribalda Delgado wrote: >>>> Describe the HSV formats >>>> >>>> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx> >>>> --- >>>> >>>> Documentation/media/uapi/v4l/hsv-formats.rst | 19 ++ >>>> Documentation/media/uapi/v4l/pixfmt-packed-hsv.rst | 253 +++++++++++++++ >>>> Documentation/media/uapi/v4l/pixfmt.rst | 1 + >>>> Documentation/media/uapi/v4l/v4l2.rst | 5 + >>>> 4 files changed, 278 insertions(+) >>>> create mode 100644 Documentation/media/uapi/v4l/hsv-formats.rst >>>> create mode 100644 Documentation/media/uapi/v4l/pixfmt-packed-hsv.rst >>>> >>>> diff --git a/Documentation/media/uapi/v4l/hsv-formats.rst >>>> b/Documentation/media/uapi/v4l/hsv-formats.rst new file mode 100644 >>>> index 000000000000..f0f2615eaa95 >>>> --- /dev/null >>>> +++ b/Documentation/media/uapi/v4l/hsv-formats.rst >>>> @@ -0,0 +1,19 @@ >>>> +.. -*- coding: utf-8; mode: rst -*- >>>> + >>>> +.. _hsv-formats: >>>> + >>>> +*********** >>>> +HSV Formats >>>> +*********** >>>> + >>>> +These formats store the color information of the image >>>> +in a geometrical representation. The colors are mapped into a >>>> +cylinder, where the angle is the HUE, the height is the VALUE >>>> +and the distance to the center is the SATURATION. This is a very >>>> +useful format for image segmentation algorithms. >>>> + >>>> + >>>> +.. toctree:: >>>> + :maxdepth: 1 >>>> + >>>> + pixfmt-packed-hsv >>>> diff --git a/Documentation/media/uapi/v4l/pixfmt-packed-hsv.rst >>>> b/Documentation/media/uapi/v4l/pixfmt-packed-hsv.rst new file mode 100644 >>>> index 000000000000..b297aa4f7ba6 >>>> --- /dev/null >>>> +++ b/Documentation/media/uapi/v4l/pixfmt-packed-hsv.rst >>>> @@ -0,0 +1,253 @@ >>>> +.. -*- coding: utf-8; mode: rst -*- >>>> + >>>> +.. _packed-hsv: >>>> + >>>> +****************** >>>> +Packed HSV formats >>>> +****************** >>>> + >>>> +*man Packed HSV formats(2)* >>>> + >>>> +Packed HSV formats >>>> + >>>> + >>>> +Description >>>> +=========== >>>> + >>>> +The HUE (h) is meassured in degrees, one LSB represents two degrees. >>> >>> Is this common ? I have a device that can handle HSV data, I need to check >>> how it maps the hue values to binary, but I'm pretty sure they cover the >>> full 0-255 range. We would then have to support the two formats. Separate >>> 4CCs are an option, but reporting the range separately (possibly through >>> the colorspace API) might be better. Any thought on that ? >> >> It's either a separate 4cc or we do something with the ycbcr_enc field >> (reinterpreted as hsv_enc). I'm not sure, I would have to think some more >> about that. > > I'm inclined to use the ycbcr_enc field, especially given that a similar usage > could be useful for RGB as well (don't ask me what it's supposed to be used > for, but I have hardware that support limiting the RGB values range to > 16-235). Limited vs full range quantization is handled by the quantization field. It's there already. Limited range RGB is needed for HDMI due to a brain-dead spec when dealing with certain kinds of TVs and configurations. Don't ask, it's horrible. Anyway, I am inclined to use ycbcr_enc as well. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
