On Wed, Nov 27, 2013 at 2:16 PM, Peter Rennert <[email protected]>
wrote:
> As a solution I have done something similar as it was proposed earlier,
> just that I derived from ndarray and kept the QImage reference it it:
>
> from PySide import QtGui as _qt
> import numpy as _np
>
> class MemoryTie(np.ndarray):
> def __new__(cls, image):
> # Retrieving parameters for _np.ndarray()
> dims = [image.height(), image.width()]
>
> strides = [[] for i in range(2)]
> strides[0] = image.bytesPerLine()
>
> bits = image.bits()
>
> if image.format() == _qt.QImage.Format_Indexed8:
> dtype = _np.uint8
> strides[1] = 1
> elif image.format() == _qt.QImage.Format_RGB32 \
> or image.format() == _qt.QImage.Format_ARGB32 \
> or image.format() == _qt.QImage.Format_ARGB32_Premultiplied:
> dtype = _np.uint32
> strides[1] = 4
> elif image.format() == _qt.QImage.Format_Invalid:
> raise ValueError("qimageview got invalid QImage")
> else:
> raise ValueError("qimageview can only handle 8- or 32-bit
> QImages")
>
> # creation of ndarray
> obj = _np.ndarray(dims, _np.uint32, bits, 0, strides,
> 'C').view(cls)
> obj._image = image
>
> return obj
Don't do that. Use my recipe. You don't really want your RGBA tuples
interpreted as uint32s, do you?
from PySide import QtGui
import numpy as np
class QImageArray(object):
def __init__(self, qimage):
shape = (qimage.height(), qimage.width(), -1)
# Generate an ndarray from the image bits and steal its
# __array_interface__ information.
arr = np.frombuffer(qimage.bits(), dtype=np.uint8).reshape(shape)
self.__array_interface__ = arr.__array_interface__
# Keep the QImage alive.
self.qimage = qimage
def qimage2ndarray(qimage):
return np.asarray(QImageArray(qimage))
qimage =
QtGui.QImage('/Users/rkern/git/scipy/scipy/misc/tests/data/icon.png')
arr = qimage2ndarray(qimage)
del qimage
print arr
--
Robert Kern
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