Python Matplotlib/PyQT4:透明图形
我将Python与PyQt4一起使用,我希望在GUI中嵌入matplotlib图形。 对我来说重要的是,Python Matplotlib/PyQT4:透明图形,python,matplotlib,pyqt4,Python,Matplotlib,Pyqt4,我将Python与PyQt4一起使用,我希望在GUI中嵌入matplotlib图形。 对我来说重要的是,图的背景与GUI的背景颜色相匹配。(实际地块周围无灰色背景) 我的部分解决方案是使用以下代码使图透明: ... fig.patch.set_alpha(0.5) ... 当在pylab模式下打印时,这很好,但是当嵌入PyQt4时,重新渲染不会清除旧图形,而是在顶部添加我提供的透明度。如下面的示例所示,这是调整窗口大小的结果: 样本是通过在mymplnavas的\uuuu init\uuuu
图的背景与GUI的背景颜色相匹配。(实际地块周围无灰色背景)
我的部分解决方案是使用以下代码使图
透明:
...
fig.patch.set_alpha(0.5)
...
当在pylab模式下打印时,这很好,但是当嵌入PyQt4时,重新渲染不会清除旧图形,而是在顶部添加我提供的透明度。如下面的示例所示,这是调整窗口大小的结果:
样本是通过在mymplnavas
的\uuuu init\uuuu
语句中添加set\u alpha(0.5)
行生成的 您在matplotlib
中发现了一个有趣的bug。Qt4
后端在重绘之前没有清除用于显示图形的qImage
,因此您可以看到阴影。通过向matplotlib.backends.backed_qt4Agg.FigureCanvasQTAgg.paintEvent添加几行代码,可以轻松解决此问题
def paintEvent(self, e):
"""
Copy the image from the Agg canvas to the qt.drawable.
In Qt, all drawing should be done inside of here when a widget is
shown onscreen.
"""
#FigureCanvasQT.paintEvent(self, e)
if DEBUG:
print('FigureCanvasQtAgg.paintEvent: ', self,
self.get_width_height())
if self.blitbox is None:
# matplotlib is in rgba byte order. QImage wants to put the bytes
# into argb format and is in a 4 byte unsigned int. Little endian
# system is LSB first and expects the bytes in reverse order
# (bgra).
if QtCore.QSysInfo.ByteOrder == QtCore.QSysInfo.LittleEndian:
stringBuffer = self.renderer._renderer.tostring_bgra()
else:
stringBuffer = self.renderer._renderer.tostring_argb()
refcnt = sys.getrefcount(stringBuffer)
qImage = QtGui.QImage(stringBuffer, self.renderer.width,
self.renderer.height,
QtGui.QImage.Format_ARGB32)
rect = qImage.rect() ### <-- added this line
p = QtGui.QPainter(self)
p.eraseRect(rect) ### <-- added this line
p.drawPixmap(QtCore.QPoint(0, 0), QtGui.QPixmap.fromImage(qImage))
# draw the zoom rectangle to the QPainter
if self.drawRect:
p.setPen(QtGui.QPen(QtCore.Qt.black, 1, QtCore.Qt.DotLine))
p.drawRect(self.rect[0], self.rect[1],
self.rect[2], self.rect[3])
p.end()
# This works around a bug in PySide 1.1.2 on Python 3.x,
# where the reference count of stringBuffer is incremented
# but never decremented by QImage.
# TODO: revert PR #1323 once the issue is fixed in PySide.
del qImage
if refcnt != sys.getrefcount(stringBuffer):
_decref(stringBuffer)
else:
bbox = self.blitbox
l, b, r, t = bbox.extents
w = int(r) - int(l)
h = int(t) - int(b)
t = int(b) + h
reg = self.copy_from_bbox(bbox)
stringBuffer = reg.to_string_argb()
qImage = QtGui.QImage(stringBuffer, w, h,
QtGui.QImage.Format_ARGB32)
pixmap = QtGui.QPixmap.fromImage(qImage)
p = QtGui.QPainter(self)
p.drawPixmap(QtCore.QPoint(l, self.renderer.height-t), pixmap)
p.end()
self.blitbox = None
self.drawRect = False
您可以修改本地安装,也可以在代码中对其进行修补
它已被合并并将出现在1.3.1中最好粘贴您在此处使用的所有代码,而不是仅提供链接。其他页面可能会更改,这将使您的问题不适定。还可以将其缩减到显示您的问题所需的最小值。谢谢您的提示。关于减少问题并将其直接发布到SO上,您是对的。就在这种情况下,我想表明,即使是官方配方也会出现问题,而不仅仅是我的潜在错误方式。在这种情况下,我认为正确的做法是将官方代码剥离到动态图部分。
diff --git a/lib/matplotlib/backends/backend_qt4agg.py b/lib/matplotlib/backends/backend_qt4agg.py
index 8433731..718d352 100644
--- a/lib/matplotlib/backends/backend_qt4agg.py
+++ b/lib/matplotlib/backends/backend_qt4agg.py
@@ -118,7 +118,9 @@ class FigureCanvasQTAgg(FigureCanvasQT, FigureCanvasAgg):
qImage = QtGui.QImage(stringBuffer, self.renderer.width,
self.renderer.height,
QtGui.QImage.Format_ARGB32)
+ rect = qImage.rect()
p = QtGui.QPainter(self)
+ p.eraseRect(rect)
p.drawPixmap(QtCore.QPoint(0, 0), QtGui.QPixmap.fromImage(qImage))
# draw the zoom rectangle to the QPainter