[libcamera-devel] [PATCH v3 19/30] py: cam: Move conversion funcs to helpers.py

Laurent Pinchart laurent.pinchart at ideasonboard.com
Sun May 29 11:17:09 CEST 2022


Hi Tomi,

Thank you for the patch.

On Fri, May 27, 2022 at 05:44:36PM +0300, Tomi Valkeinen wrote:
> Move conversion functions from cam_qt.py to helpers.py to clean up the
> code and so that they can be used from other cam renderers.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> ---
>  src/py/cam/cam_qt.py                 | 157 +--------------------------
>  src/py/cam/{cam_qt.py => helpers.py} | 155 +-------------------------
>  2 files changed, 2 insertions(+), 310 deletions(-)
>  copy src/py/cam/{cam_qt.py => helpers.py} (55%)
> 
> diff --git a/src/py/cam/cam_qt.py b/src/py/cam/cam_qt.py
> index c294c999..af4b0f86 100644
> --- a/src/py/cam/cam_qt.py
> +++ b/src/py/cam/cam_qt.py
> @@ -1,19 +1,15 @@
>  # SPDX-License-Identifier: GPL-2.0-or-later
>  # Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
> -#
> -# Debayering code from PiCamera documentation
>  
> +from helpers import mfb_to_rgb
>  from io import BytesIO
> -from numpy.lib.stride_tricks import as_strided
>  from PIL import Image
>  from PIL.ImageQt import ImageQt
>  from PyQt5 import QtCore, QtGui, QtWidgets
>  import libcamera as libcam
>  import libcamera.utils
> -import numpy as np
>  import sys
>  
> -

I think pycodestyle would complain about this dropped blank line. Same
in helpers.py. Apart from that,

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

>  def rgb_to_pix(rgb):
>      img = Image.frombuffer('RGB', (rgb.shape[1], rgb.shape[0]), rgb)
>      qim = ImageQt(img).copy()
> @@ -21,157 +17,6 @@ def rgb_to_pix(rgb):
>      return pix
>  
>  
> -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
> -    rgb[g0[1]::2, g0[0]::2, 1] = data[g0[1]::2, g0[0]::2]  # Green
> -    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
> -
> -    # 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 by a byte representation of
> -    # the Bayer filter which we construct first:
> -
> -    bayer = np.zeros(rgb.shape, dtype=np.uint8)
> -    bayer[r0[1]::2, r0[0]::2, 0] = 1  # Red
> -    bayer[g0[1]::2, g0[0]::2, 1] = 1  # Green
> -    bayer[g1[1]::2, g1[0]::2, 1] = 1  # Green
> -    bayer[b0[1]::2, b0[0]::2, 2] = 1  # Blue
> -
> -    # Allocate an array to hold our output with the same shape as the input
> -    # data. After this we define the size of window that will be used to
> -    # calculate each weighted average (3x3). Then we pad out the rgb and
> -    # bayer arrays, adding blank pixels at their edges to compensate for the
> -    # size of the window when calculating averages for edge pixels.
> -
> -    output = np.empty(rgb.shape, dtype=rgb.dtype)
> -    window = (3, 3)
> -    borders = (window[0] - 1, window[1] - 1)
> -    border = (borders[0] // 2, borders[1] // 2)
> -
> -    rgb = np.pad(rgb, [
> -        (border[0], border[0]),
> -        (border[1], border[1]),
> -        (0, 0),
> -    ], 'constant')
> -    bayer = np.pad(bayer, [
> -        (border[0], border[0]),
> -        (border[1], border[1]),
> -        (0, 0),
> -    ], 'constant')
> -
> -    # For each plane in the RGB data, we use a nifty numpy trick
> -    # (as_strided) to construct a view over the plane of 3x3 matrices. We do
> -    # the same for the bayer array, then use Einstein summation on each
> -    # (np.sum is simpler, but copies the data so it's slower), and divide
> -    # the results to get our weighted average:
> -
> -    for plane in range(3):
> -        p = rgb[..., plane]
> -        b = bayer[..., plane]
> -        pview = as_strided(p, shape=(
> -            p.shape[0] - borders[0],
> -            p.shape[1] - borders[1]) + window, strides=p.strides * 2)
> -        bview = as_strided(b, shape=(
> -            b.shape[0] - borders[0],
> -            b.shape[1] - borders[1]) + window, strides=b.strides * 2)
> -        psum = np.einsum('ijkl->ij', pview)
> -        bsum = np.einsum('ijkl->ij', bview)
> -        output[..., plane] = psum // bsum
> -
> -    return output
> -
> -
> -def to_rgb(fmt, size, data):
> -    w = size.width
> -    h = size.height
> -
> -    if fmt == libcam.formats.YUYV:
> -        # YUV422
> -        yuyv = data.reshape((h, w // 2 * 4))
> -
> -        # YUV444
> -        yuv = np.empty((h, w, 3), dtype=np.uint8)
> -        yuv[:, :, 0] = yuyv[:, 0::2]                    # Y
> -        yuv[:, :, 1] = yuyv[:, 1::4].repeat(2, axis=1)  # U
> -        yuv[:, :, 2] = yuyv[:, 3::4].repeat(2, axis=1)  # V
> -
> -        m = np.array([
> -            [1.0, 1.0, 1.0],
> -            [-0.000007154783816076815, -0.3441331386566162, 1.7720025777816772],
> -            [1.4019975662231445, -0.7141380310058594, 0.00001542569043522235]
> -        ])
> -
> -        rgb = np.dot(yuv, m)
> -        rgb[:, :, 0] -= 179.45477266423404
> -        rgb[:, :, 1] += 135.45870971679688
> -        rgb[:, :, 2] -= 226.8183044444304
> -        rgb = rgb.astype(np.uint8)
> -
> -    elif fmt == libcam.formats.RGB888:
> -        rgb = data.reshape((h, w, 3))
> -        rgb[:, :, [0, 1, 2]] = rgb[:, :, [2, 1, 0]]
> -
> -    elif fmt == libcam.formats.BGR888:
> -        rgb = data.reshape((h, w, 3))
> -
> -    elif fmt in [libcam.formats.ARGB8888, libcam.formats.XRGB8888]:
> -        rgb = data.reshape((h, w, 4))
> -        rgb = np.flip(rgb, axis=2)
> -        # drop alpha component
> -        rgb = np.delete(rgb, np.s_[0::4], axis=2)
> -
> -    elif str(fmt).startswith('S'):
> -        fmt = str(fmt)
> -        bayer_pattern = fmt[1:5]
> -        bitspp = int(fmt[5:])
> -
> -        # \todo shifting leaves the lowest bits 0
> -        if bitspp == 8:
> -            data = data.reshape((h, w))
> -            data = data.astype(np.uint16) << 8
> -        elif bitspp in [10, 12]:
> -            data = data.view(np.uint16)
> -            data = data.reshape((h, w))
> -            data = data << (16 - bitspp)
> -        else:
> -            raise Exception('Bad bitspp:' + str(bitspp))
> -
> -        idx = bayer_pattern.find('R')
> -        assert(idx != -1)
> -        r0 = (idx % 2, idx // 2)
> -
> -        idx = bayer_pattern.find('G')
> -        assert(idx != -1)
> -        g0 = (idx % 2, idx // 2)
> -
> -        idx = bayer_pattern.find('G', idx + 1)
> -        assert(idx != -1)
> -        g1 = (idx % 2, idx // 2)
> -
> -        idx = bayer_pattern.find('B')
> -        assert(idx != -1)
> -        b0 = (idx % 2, idx // 2)
> -
> -        rgb = demosaic(data, r0, g0, g1, b0)
> -        rgb = (rgb >> 8).astype(np.uint8)
> -
> -    else:
> -        rgb = None
> -
> -    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
> diff --git a/src/py/cam/cam_qt.py b/src/py/cam/helpers.py
> similarity index 55%
> copy from src/py/cam/cam_qt.py
> copy to src/py/cam/helpers.py
> index c294c999..d571c753 100644
> --- a/src/py/cam/cam_qt.py
> +++ b/src/py/cam/helpers.py
> @@ -3,23 +3,10 @@
>  #
>  # Debayering code from PiCamera documentation
>  
> -from io import BytesIO
>  from numpy.lib.stride_tricks import as_strided
> -from PIL import Image
> -from PIL.ImageQt import ImageQt
> -from PyQt5 import QtCore, QtGui, QtWidgets
>  import libcamera as libcam
>  import libcamera.utils
>  import numpy as np
> -import sys
> -
> -
> -def rgb_to_pix(rgb):
> -    img = Image.frombuffer('RGB', (rgb.shape[1], rgb.shape[0]), rgb)
> -    qim = ImageQt(img).copy()
> -    pix = QtGui.QPixmap.fromImage(qim)
> -    return pix
> -
>  
>  def demosaic(data, r0, g0, g1, b0):
>      # Separate the components from the Bayer data to RGB planes
> @@ -166,147 +153,7 @@ def to_rgb(fmt, size, data):
>  
>  
>  # A naive format conversion to 24-bit RGB
> -def mfb_to_rgb(mfb, cfg):
> +def mfb_to_rgb(mfb: libcamera.utils.MappedFrameBuffer, cfg: libcam.StreamConfiguration):
>      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
> -
> -        self.cm = state.cm
> -        self.contexts = state.contexts
> -
> -    def setup(self):
> -        self.app = QtWidgets.QApplication([])
> -
> -        windows = []
> -
> -        for ctx in self.contexts:
> -            for stream in ctx.streams:
> -                window = MainWindow(ctx, stream)
> -                window.show()
> -                windows.append(window)
> -
> -        self.windows = windows
> -
> -    def run(self):
> -        camnotif = QtCore.QSocketNotifier(self.cm.event_fd, QtCore.QSocketNotifier.Read)
> -        camnotif.activated.connect(lambda _: self.readcam())
> -
> -        keynotif = QtCore.QSocketNotifier(sys.stdin.fileno(), QtCore.QSocketNotifier.Read)
> -        keynotif.activated.connect(lambda _: self.readkey())
> -
> -        print('Capturing...')
> -
> -        self.app.exec()
> -
> -        print('Exiting...')
> -
> -    def readcam(self):
> -        running = self.state.event_handler()
> -
> -        if not running:
> -            self.app.quit()
> -
> -    def readkey(self):
> -        sys.stdin.readline()
> -        self.app.quit()
> -
> -    def request_handler(self, ctx, req):
> -        buffers = req.buffers
> -
> -        for stream, fb in buffers.items():
> -            wnd = next(wnd for wnd in self.windows if wnd.stream == stream)
> -
> -            wnd.handle_request(stream, fb)
> -
> -        self.state.request_processed(ctx, req)
> -
> -    def cleanup(self):
> -        for w in self.windows:
> -            w.close()
> -
> -
> -class MainWindow(QtWidgets.QWidget):
> -    def __init__(self, ctx, stream):
> -        super().__init__()
> -
> -        self.ctx = ctx
> -        self.stream = stream
> -
> -        self.label = QtWidgets.QLabel()
> -
> -        windowLayout = QtWidgets.QHBoxLayout()
> -        self.setLayout(windowLayout)
> -
> -        windowLayout.addWidget(self.label)
> -
> -        controlsLayout = QtWidgets.QVBoxLayout()
> -        windowLayout.addLayout(controlsLayout)
> -
> -        windowLayout.addStretch()
> -
> -        group = QtWidgets.QGroupBox('Info')
> -        groupLayout = QtWidgets.QVBoxLayout()
> -        group.setLayout(groupLayout)
> -        controlsLayout.addWidget(group)
> -
> -        lab = QtWidgets.QLabel(ctx.id)
> -        groupLayout.addWidget(lab)
> -
> -        self.frameLabel = QtWidgets.QLabel()
> -        groupLayout.addWidget(self.frameLabel)
> -
> -        group = QtWidgets.QGroupBox('Properties')
> -        groupLayout = QtWidgets.QVBoxLayout()
> -        group.setLayout(groupLayout)
> -        controlsLayout.addWidget(group)
> -
> -        camera = ctx.camera
> -
> -        for cid, cv in camera.properties.items():
> -            lab = QtWidgets.QLabel()
> -            lab.setText('{} = {}'.format(cid, cv))
> -            groupLayout.addWidget(lab)
> -
> -        group = QtWidgets.QGroupBox('Controls')
> -        groupLayout = QtWidgets.QVBoxLayout()
> -        group.setLayout(groupLayout)
> -        controlsLayout.addWidget(group)
> -
> -        for cid, cinfo in camera.controls.items():
> -            lab = QtWidgets.QLabel()
> -            lab.setText('{} = {}/{}/{}'
> -                        .format(cid, cinfo.min, cinfo.max, cinfo.default))
> -            groupLayout.addWidget(lab)
> -
> -        controlsLayout.addStretch()
> -
> -    def buf_to_qpixmap(self, stream, fb):
> -        with libcamera.utils.MappedFrameBuffer(fb) as mfb:
> -            cfg = stream.configuration
> -
> -            if cfg.pixel_format == libcam.formats.MJPEG:
> -                img = Image.open(BytesIO(mfb.planes[0]))
> -                qim = ImageQt(img).copy()
> -                pix = QtGui.QPixmap.fromImage(qim)
> -            else:
> -                rgb = mfb_to_rgb(mfb, cfg)
> -                if rgb is None:
> -                    raise Exception('Format not supported: ' + cfg.pixel_format)
> -
> -                pix = rgb_to_pix(rgb)
> -
> -        return pix
> -
> -    def handle_request(self, stream, fb):
> -        ctx = self.ctx
> -
> -        pix = self.buf_to_qpixmap(stream, fb)
> -        self.label.setPixmap(pix)
> -
> -        self.frameLabel.setText('Queued: {}\nDone: {}\nFps: {:.2f}'
> -                                .format(ctx.reqs_queued, ctx.reqs_completed, ctx.fps))

-- 
Regards,

Laurent Pinchart


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