[libcamera-devel] [PATCH v2 10/13] py: cam_qt: cosmetic cleanups

[Laurent Pinchart]

Hi Tomi,

Thank you for the patch.

On Tue, May 17, 2022 at 05:33:22PM +0300, Tomi Valkeinen wrote:
> Drop irrelevant or wrong comments, merge separate_components() into
> demosaic(), and add mfb_to_rgb().
> 
> No functional changes.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
>  src/py/cam/cam_qt.py | 64 +++++++++-----------------------------------
>  1 file changed, 13 insertions(+), 51 deletions(-)
> 
> diff --git a/src/py/cam/cam_qt.py b/src/py/cam/cam_qt.py
> index 5753f0b2..fb485b9b 100644
> --- a/src/py/cam/cam_qt.py
> +++ b/src/py/cam/cam_qt.py
> @@ -19,19 +19,8 @@ def rgb_to_pix(rgb):
>      return pix
>  
>  
> -def separate_components(data, r0, g0, g1, b0):
> -    # Now to split the data up into its red, green, and blue components. The
> -    # Bayer pattern of the OV5647 sensor is BGGR. In other words the first
> -    # row contains alternating green/blue elements, the second row contains
> -    # alternating red/green elements, and so on as illustrated below:
> -    #
> -    # GBGBGBGBGBGBGB
> -    # RGRGRGRGRGRGRG
> -    # GBGBGBGBGBGBGB
> -    # RGRGRGRGRGRGRG
> -    #
> -    # Please note that if you use vflip or hflip to change the orientation
> -    # of the capture, you must flip the Bayer pattern accordingly
> +def demosaic(data, r0, g0, g1, b0):
> +    # Separate the components from the Bayer data to RGB planes
>  
>      rgb = np.zeros(data.shape + (3,), dtype=data.dtype)
>      rgb[r0[1]::2, r0[0]::2, 0] = data[r0[1]::2, r0[0]::2]  # Red
> @@ -39,17 +28,9 @@ def separate_components(data, r0, g0, g1, b0):
>      rgb[g1[1]::2, g1[0]::2, 1] = data[g1[1]::2, g1[0]::2]  # Green
>      rgb[b0[1]::2, b0[0]::2, 2] = data[b0[1]::2, b0[0]::2]  # Blue
>  
> -    return rgb
> -
> -
> -def demosaic(rgb, r0, g0, g1, b0):
> -    # At this point we now have the raw Bayer data with the correct values
> -    # and colors but the data still requires de-mosaicing and
> -    # post-processing. If you wish to do this yourself, end the script here!
> -    #
>      # Below we present a fairly naive de-mosaic method that simply
>      # calculates the weighted average of a pixel based on the pixels
> -    # surrounding it. The weighting is provided b0[1] a b0[1]te representation of
> +    # surrounding it. The weighting is provided by a byte representation of
>      # the Bayer filter which we construct first:
>  
>      bayer = np.zeros(rgb.shape, dtype=np.uint8)
> @@ -69,29 +50,6 @@ def demosaic(rgb, r0, g0, g1, b0):
>      borders = (window[0] - 1, window[1] - 1)
>      border = (borders[0] // 2, borders[1] // 2)
>  
> -    # rgb_pad = np.zeros((
> -    #    rgb.shape[0] + borders[0],
> -    #    rgb.shape[1] + borders[1],
> -    #    rgb.shape[2]), dtype=rgb.dtype)
> -    # rgb_pad[
> -    #    border[0]:rgb_pad.shape[0] - border[0],
> -    #    border[1]:rgb_pad.shape[1] - border[1],
> -    #    :] = rgb
> -    # rgb = rgb_pad
> -    #
> -    # bayer_pad = np.zeros((
> -    #    bayer.shape[0] + borders[0],
> -    #    bayer.shape[1] + borders[1],
> -    #    bayer.shape[2]), dtype=bayer.dtype)
> -    # bayer_pad[
> -    #    border[0]:bayer_pad.shape[0] - border[0],
> -    #    border[1]:bayer_pad.shape[1] - border[1],
> -    #    :] = bayer
> -    # bayer = bayer_pad
> -
> -    # In numpy >=1.7.0 just use np.pad (version in Raspbian is 1.6.2 at the
> -    # time of writing...)
> -    #
>      rgb = np.pad(rgb, [
>          (border[0], border[0]),
>          (border[1], border[1]),
> @@ -168,7 +126,7 @@ def to_rgb(fmt, size, data):
>          bayer_pattern = fmt[1:5]
>          bitspp = int(fmt[5:])
>  
> -        # TODO: shifting leaves the lowest bits 0
> +        # \todo shifting leaves the lowest bits 0
>          if bitspp == 8:
>              data = data.reshape((h, w))
>              data = data.astype(np.uint16) << 8
> @@ -195,8 +153,7 @@ def to_rgb(fmt, size, data):
>          assert(idx != -1)
>          b0 = (idx % 2, idx // 2)
>  
> -        rgb = separate_components(data, r0, g0, g1, b0)
> -        rgb = demosaic(rgb, r0, g0, g1, b0)
> +        rgb = demosaic(data, r0, g0, g1, b0)
>          rgb = (rgb >> 8).astype(np.uint8)
>  
>      else:
> @@ -205,6 +162,13 @@ def to_rgb(fmt, size, data):
>      return rgb
>  
>  
> +# A naive format conversion to 24-bit RGB
> +def mfb_to_rgb(mfb, cfg):
> +    data = np.array(mfb.planes[0], dtype=np.uint8)
> +    rgb = to_rgb(cfg.pixel_format, cfg.size, data)
> +    return rgb
> +
> +
>  class QtRenderer:
>      def __init__(self, state):
>          self.state = state
> @@ -334,9 +298,7 @@ class MainWindow(QtWidgets.QWidget):
>                  qim = ImageQt(img).copy()
>                  pix = QtGui.QPixmap.fromImage(qim)
>              else:
> -                data = np.array(mfb.planes[0], dtype=np.uint8)
> -                rgb = to_rgb(cfg.pixel_format, cfg.size, data)
> -
> +                rgb = mfb_to_rgb(mfb, cfg)
>                  if rgb is None:
>                      raise Exception('Format not supported: ' + cfg.pixel_format)
>  

-- 
Regards,

Laurent Pinchart