def imread(filename):
"""
Read an image using QT's QImage.load
"""
qtimg = QImage()
if not qtimg.load(filename):
# QImage.load() returns false on failure, so raise an exception
raise IOError('Unable to load file %s' % filename)
if qtimg.depth() == 1:
raise IOError('1-bit images currently not supported')
# TODO: Warn about other odd formats we don't currently handle properly,
# such as the odd 16-bit packed formats QT supports
arrayptr = qtimg.bits()
# QT may pad the image, so we need to use bytesPerLine, not width for
# the conversion to a numpy array
bytes_per_pixel = qtimg.depth() // 8
pixels_per_line = qtimg.bytesPerLine() // bytes_per_pixel
img_size = pixels_per_line * qtimg.height() * bytes_per_pixel
arrayptr.setsize(img_size)
img = np.array(arrayptr)
# Reshape and trim down to correct dimensions
if bytes_per_pixel > 1:
img = img.reshape((qtimg.height(), pixels_per_line, bytes_per_pixel))
img = img[:, :qtimg.width(), :]
else:
img = img.reshape((qtimg.height(), pixels_per_line))
img = img[:, :qtimg.width()]
# Strip qt's false alpha channel if needed
# and reorder color axes as required
if bytes_per_pixel == 4 and not qtimg.hasAlphaChannel():
img = img[:, :, 2::-1]
elif bytes_per_pixel == 4:
img[:, :, 0:3] = img[:, :, 2::-1]
return img
def get_font_array(sz, chars=DEFAULT_CHARS):
from qtpy.QtGui import QFont, QPainter, QColor
font = QFont()
font.setFixedPitch(True)
font.setPixelSize(int(sz))
font.setStyleStrategy(QFont.NoAntialias)
dummy = QImage(10, 10, QImage.Format_ARGB32)
pnt = QPainter(dummy)
pnt.setFont(font)
metric = pnt.fontMetrics()
rct = metric.boundingRect(chars)
pnt.end()
h = rct.height()
w = rct.width()
img = QImage(w, h, QImage.Format_ARGB32)
paint = QPainter()
paint.begin(img)
paint.setFont(font)
paint.setBrush(QColor(255, 255, 255))
paint.setPen(QColor(255, 255, 255))
paint.drawRect(0, 0, w + 1, h + 1)
paint.setPen(QColor(0, 0, 0))
paint.setBrush(QColor(0, 0, 0))
paint.drawText(0, paint.fontMetrics().ascent(), chars)
paint.end()
try:
try:
# PyQt4 (at least until Qt 4.8)
data = img.bits().asstring(img.numBytes())
except AttributeError:
if PYSIDE2:
# PySide2
data = bytes(img.bits())
else:
# PyQt5
data = img.bits().asstring(img.byteCount())
except SystemError:
# PyQt4 (4.11.3) and PyQt5 (5.3.2) on Python 3
return
npy = np.frombuffer(data, np.uint8)
npy.shape = img.height(), int(img.bytesPerLine() / 4), 4
return npy[:, :, 0]
def imread(filename):
"""
Read an image using QT's QImage.load
"""
warn(
'`qt` plugin is deprecated and will be removed in 0.20. '
'For alternatives, refer to '
'https://scikit-image.org/docs/stable/user_guide/visualization.html',
FutureWarning,
stacklevel=2)
qtimg = QImage()
if not qtimg.load(filename):
# QImage.load() returns false on failure, so raise an exception
raise IOError('Unable to load file %s' % filename)
if qtimg.depth() == 1:
raise IOError('1-bit images currently not supported')
# TODO: Warn about other odd formats we don't currently handle properly,
# such as the odd 16-bit packed formats QT supports
arrayptr = qtimg.bits()
# QT may pad the image, so we need to use bytesPerLine, not width for
# the conversion to a numpy array
bytes_per_pixel = qtimg.depth() // 8
pixels_per_line = qtimg.bytesPerLine() // bytes_per_pixel
img_size = pixels_per_line * qtimg.height() * bytes_per_pixel
arrayptr.setsize(img_size)
img = np.array(arrayptr)
# Reshape and trim down to correct dimensions
if bytes_per_pixel > 1:
img = img.reshape((qtimg.height(), pixels_per_line, bytes_per_pixel))
img = img[:, :qtimg.width(), :]
else:
img = img.reshape((qtimg.height(), pixels_per_line))
img = img[:, :qtimg.width()]
# Strip qt's false alpha channel if needed
# and reorder color axes as required
if bytes_per_pixel == 4 and not qtimg.hasAlphaChannel():
img = img[:, :, 2::-1]
elif bytes_per_pixel == 4:
img[:, :, 0:3] = img[:, :, 2::-1]
return img
