pyqtgraph/pyqtgraph/exporters/ImageExporter.py
Karl Georg Bedrich 68b8dbac1a
moved some functionality from method 'export' to new method (#390)
* moved some functionality from method 'export' to new method
'getSupportedFormats' making it accessible from outside
2020-06-01 11:05:39 -07:00

114 lines
4.3 KiB
Python

from .Exporter import Exporter
from ..parametertree import Parameter
from ..Qt import QtGui, QtCore, QtSvg, QT_LIB
from .. import functions as fn
import numpy as np
__all__ = ['ImageExporter']
class ImageExporter(Exporter):
Name = "Image File (PNG, TIF, JPG, ...)"
allowCopy = True
def __init__(self, item):
Exporter.__init__(self, item)
tr = self.getTargetRect()
if isinstance(item, QtGui.QGraphicsItem):
scene = item.scene()
else:
scene = item
bgbrush = scene.views()[0].backgroundBrush()
bg = bgbrush.color()
if bgbrush.style() == QtCore.Qt.NoBrush:
bg.setAlpha(0)
self.params = Parameter(name='params', type='group', children=[
{'name': 'width', 'type': 'int', 'value': int(tr.width()), 'limits': (0, None)},
{'name': 'height', 'type': 'int', 'value': int(tr.height()), 'limits': (0, None)},
{'name': 'antialias', 'type': 'bool', 'value': True},
{'name': 'background', 'type': 'color', 'value': bg},
{'name': 'invertValue', 'type': 'bool', 'value': False}
])
self.params.param('width').sigValueChanged.connect(self.widthChanged)
self.params.param('height').sigValueChanged.connect(self.heightChanged)
def widthChanged(self):
sr = self.getSourceRect()
ar = float(sr.height()) / sr.width()
self.params.param('height').setValue(int(self.params['width'] * ar), blockSignal=self.heightChanged)
def heightChanged(self):
sr = self.getSourceRect()
ar = float(sr.width()) / sr.height()
self.params.param('width').setValue(int(self.params['height'] * ar), blockSignal=self.widthChanged)
def parameters(self):
return self.params
@staticmethod
def getSupportedImageFormats():
filter = ["*."+f.data().decode('utf-8') for f in QtGui.QImageWriter.supportedImageFormats()]
preferred = ['*.png', '*.tif', '*.jpg']
for p in preferred[::-1]:
if p in filter:
filter.remove(p)
filter.insert(0, p)
return filter
def export(self, fileName=None, toBytes=False, copy=False):
if fileName is None and not toBytes and not copy:
filter = self.getSupportedImageFormats()
self.fileSaveDialog(filter=filter)
return
w = int(self.params['width'])
h = int(self.params['height'])
if w == 0 or h == 0:
raise Exception("Cannot export image with size=0 (requested "
"export size is %dx%d)" % (w, h))
targetRect = QtCore.QRect(0, 0, w, h)
sourceRect = self.getSourceRect()
bg = np.empty((h, w, 4), dtype=np.ubyte)
color = self.params['background']
bg[:,:,0] = color.blue()
bg[:,:,1] = color.green()
bg[:,:,2] = color.red()
bg[:,:,3] = color.alpha()
self.png = fn.makeQImage(bg, alpha=True, copy=False, transpose=False)
self.bg = bg
## set resolution of image:
origTargetRect = self.getTargetRect()
resolutionScale = targetRect.width() / origTargetRect.width()
#self.png.setDotsPerMeterX(self.png.dotsPerMeterX() * resolutionScale)
#self.png.setDotsPerMeterY(self.png.dotsPerMeterY() * resolutionScale)
painter = QtGui.QPainter(self.png)
#dtr = painter.deviceTransform()
try:
self.setExportMode(True, {'antialias': self.params['antialias'], 'background': self.params['background'], 'painter': painter, 'resolutionScale': resolutionScale})
painter.setRenderHint(QtGui.QPainter.Antialiasing, self.params['antialias'])
self.getScene().render(painter, QtCore.QRectF(targetRect), QtCore.QRectF(sourceRect))
finally:
self.setExportMode(False)
painter.end()
if self.params['invertValue']:
mn = bg[...,:3].min(axis=2)
mx = bg[...,:3].max(axis=2)
d = (255 - mx) - mn
bg[...,:3] += d[...,np.newaxis]
if copy:
QtGui.QApplication.clipboard().setImage(self.png)
elif toBytes:
return self.png
else:
return self.png.save(fileName)
ImageExporter.register()