def numpy_to_QImage(array, QImage_format=None):
"""
Transform numpy array into QImage.
Data copy is avoided if possible.
The QImage.data attribute contain the underlying numpy array
to prevent python freeing that memory while the image is in use.
(same or a copy of the given array, if copy was needed )
"""
if numpy.ndim(array) == 2:
h, w = array.shape
if (QImage_format is None) or (
QImage_format is QImage.Format_Indexed8
): # lent pour affichage sur QWidget par contre rapide pour QGlWidget
qimage = QImage(
numpy.require(array, numpy.uint8, "C").data,
w,
h,
QImage.Format_Indexed8,
)
qimage.setColorTable(grayTable)
qimage.data = array
return qimage
elif QImage_format is QImage.Format_RGB32:
bgrx = numpy.require(
array * 65793, numpy.uint32,
"C") # 0.7 a 0.9 msec (65793 = (1<<16)+(1<<8)+1)
qimage = QImage(bgrx.data, w, h, QImage.Format_RGB32)
qimage.data = (
bgrx # permet de garder un reference de l'image et lui eviter un destruction qui fait planter PySide2
)
return qimage
elif QImage_format is QImage.Format_ARGB32:
bgra = numpy.empty((h, w, 4), numpy.uint8, "C") # 0.01 mec
bgra[..., 0] = array
bgra[..., 1] = array # 0.38 msec
bgra[..., 2] = array
bgra[..., 3] = 255
qimage = QImage(bgra.data, w, h, QImage.Format_ARGB32)
qimage.data = bgra
return qimage
elif numpy.ndim(array) == 3:
h, w, channels = array.shape
if channels == 3:
bgrx = numpy.empty((h, w, 4), numpy.uint8, "C")
bgrx[..., :3] = array
qimage = QImage(bgrx.data, w, h, QImage.Format_RGB32)
qimage.data = bgrx
return qimage
elif channels == 4:
bgrx = numpy.require(array, numpy.uint8, "C")
qimage = QImage(bgrx.data, w, h, QImage.Format_ARGB32)
qimage.data = bgrx
return qimage
else:
raise ValueError(
"Color images can expects the last dimension to contain exactly three (R,G,B) or four (R,G,B,A) channels"
)
else:
raise ValueError("can only convert 2D or 3D arrays")
