PyQt5: Overlay two pixmaps with alpha value using QPainter
1
I'm trying to overlay 2 pixmaps and convert them into a single pixmap in a QGraphics scene. Both pixmaps are transparent at certain locations. I want to combine the maps using the 'SourceOver' blend type listed here: I have a simple toy example below to illustrate my issue where I have created two dummy transparent pixmaps, one green and one blue. In reality, these maps are loaded from images and painted over, but this example reproduces the problem. Based on this How to add an image on the top of another image?, the approach I tried (4 lines commented out) was to create a QPainter with one of the pixmaps and then draw the other pixmap on top of it, however that crashes the program. Any ideas on how to fix this? I eventually want to be able to save the combined pixmap.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtGui import QPixmap, QPainter, QPen, QBrush, QPainterPath
from PyQt5.QtCore import (QLineF, QPointF, QRectF, Qt)
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent):
super(Viewer, self).__init__(parent)
self._scene = QtWidgets.QGraphicsScene(self)
self.photo = QtWidgets.QGraphicsPixmapItem()
self.label = QtWidgets.QGraphicsPixmapItem()
self._scene.addItem(self.photo)
self._scene.addItem(self.label)
self.setScene(self._scene)
def overlayMaps(self):
blue = QtGui.QPixmap(600, 600)
blue.fill(QtGui.QColor(0,0,255,0))
p = QPainter(blue)
self.pen = QPen()
self.pen.setColor(QtGui.QColor(0,0,255,255))
self.pen.setWidth(10)
p.setPen(self.pen)
p.drawLine(0,0,600,600)
green = QtGui.QPixmap(600, 600)
green.fill(QtGui.QColor(0,255,0,0))
p = QPainter(green)
self.pen = QPen()
self.pen.setColor(QtGui.QColor(0,255,0,255))
self.pen.setWidth(10)
p.setPen(self.pen)
p.drawLine(600,0,0,600)
self.photo.setPixmap(blue)
self.label.setPixmap(green)
resultPixmap = QtGui.QPixmap(self.photo.pixmap().width(), self.photo.pixmap().height())
# resultPainter = QtGui.QPainter(resultPixmap)
# resultPainter.setCompositionMode(QtGui.QPainter.CompositionMode_SourceOver)
# resultPainter.drawPixmap(300,300, self.photo.pixmap())
# resultPainter.drawPixmap(300,300, self.label.pixmap())
def saveOverlayMap(self):
pass
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.viewer = Viewer(self)
self.viewer.overlayMaps()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Window()
window.setGeometry(500, 300, 600, 600)
window.show()
sys.exit(app.exec_())
python pyqt pyqt5 qpainter qpixmap
edited Nov 21 '18 at 23:01
eyllanesc
77.8k103156
asked Nov 21 '18 at 21:38
CSforStructuralEngineerCSforStructuralEngineer
687
|
show 3 more comments
1
I'm trying to overlay 2 pixmaps and convert them into a single pixmap in a QGraphics scene. Both pixmaps are transparent at certain locations. I want to combine the maps using the 'SourceOver' blend type listed here: I have a simple toy example below to illustrate my issue where I have created two dummy transparent pixmaps, one green and one blue. In reality, these maps are loaded from images and painted over, but this example reproduces the problem. Based on this How to add an image on the top of another image?, the approach I tried (4 lines commented out) was to create a QPainter with one of the pixmaps and then draw the other pixmap on top of it, however that crashes the program. Any ideas on how to fix this? I eventually want to be able to save the combined pixmap.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtGui import QPixmap, QPainter, QPen, QBrush, QPainterPath
from PyQt5.QtCore import (QLineF, QPointF, QRectF, Qt)
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent):
super(Viewer, self).__init__(parent)
self._scene = QtWidgets.QGraphicsScene(self)
self.photo = QtWidgets.QGraphicsPixmapItem()
self.label = QtWidgets.QGraphicsPixmapItem()
self._scene.addItem(self.photo)
self._scene.addItem(self.label)
self.setScene(self._scene)
def overlayMaps(self):
blue = QtGui.QPixmap(600, 600)
blue.fill(QtGui.QColor(0,0,255,0))
p = QPainter(blue)
self.pen = QPen()
self.pen.setColor(QtGui.QColor(0,0,255,255))
self.pen.setWidth(10)
p.setPen(self.pen)
p.drawLine(0,0,600,600)
green = QtGui.QPixmap(600, 600)
green.fill(QtGui.QColor(0,255,0,0))
p = QPainter(green)
self.pen = QPen()
self.pen.setColor(QtGui.QColor(0,255,0,255))
self.pen.setWidth(10)
p.setPen(self.pen)
p.drawLine(600,0,0,600)
self.photo.setPixmap(blue)
self.label.setPixmap(green)
resultPixmap = QtGui.QPixmap(self.photo.pixmap().width(), self.photo.pixmap().height())
# resultPainter = QtGui.QPainter(resultPixmap)
# resultPainter.setCompositionMode(QtGui.QPainter.CompositionMode_SourceOver)
# resultPainter.drawPixmap(300,300, self.photo.pixmap())
# resultPainter.drawPixmap(300,300, self.label.pixmap())
def saveOverlayMap(self):
pass
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.viewer = Viewer(self)
self.viewer.overlayMaps()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Window()
window.setGeometry(500, 300, 600, 600)
window.show()
sys.exit(app.exec_())
python pyqt pyqt5 qpainter qpixmap
edited Nov 21 '18 at 23:01
eyllanesc
77.8k103156
asked Nov 21 '18 at 21:38
CSforStructuralEngineerCSforStructuralEngineer
687
both items have the same pixmap, do not you think that's wrong?
– eyllanesc
Nov 21 '18 at 22:13
The code snippet is just to illustrate the issue. In my full code, the pixmaps are different.
– CSforStructuralEngineer
Nov 21 '18 at 22:14
you could then show that in your question, you can place both pixmaps in your question
– eyllanesc
Nov 21 '18 at 22:15
Okay, edited the question and code
– CSforStructuralEngineer
Nov 21 '18 at 22:18
1
I have already published a solution, hopefully what you are looking for. On the other hand now his example is much better, even if it is a trivial example his code must be a Minimal, Complete, and Verifiable example, that is, something that allows us to take as a basis to try to provide you with a solution. :-)
– eyllanesc
Nov 21 '18 at 22:54
|
show 3 more comments
1
1
1
I'm trying to overlay 2 pixmaps and convert them into a single pixmap in a QGraphics scene. Both pixmaps are transparent at certain locations. I want to combine the maps using the 'SourceOver' blend type listed here: I have a simple toy example below to illustrate my issue where I have created two dummy transparent pixmaps, one green and one blue. In reality, these maps are loaded from images and painted over, but this example reproduces the problem. Based on this How to add an image on the top of another image?, the approach I tried (4 lines commented out) was to create a QPainter with one of the pixmaps and then draw the other pixmap on top of it, however that crashes the program. Any ideas on how to fix this? I eventually want to be able to save the combined pixmap.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtGui import QPixmap, QPainter, QPen, QBrush, QPainterPath
from PyQt5.QtCore import (QLineF, QPointF, QRectF, Qt)
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent):
super(Viewer, self).__init__(parent)
self._scene = QtWidgets.QGraphicsScene(self)
self.photo = QtWidgets.QGraphicsPixmapItem()
self.label = QtWidgets.QGraphicsPixmapItem()
self._scene.addItem(self.photo)
self._scene.addItem(self.label)
self.setScene(self._scene)
def overlayMaps(self):
blue = QtGui.QPixmap(600, 600)
blue.fill(QtGui.QColor(0,0,255,0))
p = QPainter(blue)
self.pen = QPen()
self.pen.setColor(QtGui.QColor(0,0,255,255))
self.pen.setWidth(10)
p.setPen(self.pen)
p.drawLine(0,0,600,600)
green = QtGui.QPixmap(600, 600)
green.fill(QtGui.QColor(0,255,0,0))
p = QPainter(green)
self.pen = QPen()
self.pen.setColor(QtGui.QColor(0,255,0,255))
self.pen.setWidth(10)
p.setPen(self.pen)
p.drawLine(600,0,0,600)
self.photo.setPixmap(blue)
self.label.setPixmap(green)
resultPixmap = QtGui.QPixmap(self.photo.pixmap().width(), self.photo.pixmap().height())
# resultPainter = QtGui.QPainter(resultPixmap)
# resultPainter.setCompositionMode(QtGui.QPainter.CompositionMode_SourceOver)
# resultPainter.drawPixmap(300,300, self.photo.pixmap())
# resultPainter.drawPixmap(300,300, self.label.pixmap())
def saveOverlayMap(self):
pass
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.viewer = Viewer(self)
self.viewer.overlayMaps()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Window()
window.setGeometry(500, 300, 600, 600)
window.show()
sys.exit(app.exec_())
python pyqt pyqt5 qpainter qpixmap
edited Nov 21 '18 at 23:01
eyllanesc
77.8k103156
asked Nov 21 '18 at 21:38
CSforStructuralEngineerCSforStructuralEngineer
687
I'm trying to overlay 2 pixmaps and convert them into a single pixmap in a QGraphics scene. Both pixmaps are transparent at certain locations. I want to combine the maps using the 'SourceOver' blend type listed here: I have a simple toy example below to illustrate my issue where I have created two dummy transparent pixmaps, one green and one blue. In reality, these maps are loaded from images and painted over, but this example reproduces the problem. Based on this How to add an image on the top of another image?, the approach I tried (4 lines commented out) was to create a QPainter with one of the pixmaps and then draw the other pixmap on top of it, however that crashes the program. Any ideas on how to fix this? I eventually want to be able to save the combined pixmap.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtGui import QPixmap, QPainter, QPen, QBrush, QPainterPath
from PyQt5.QtCore import (QLineF, QPointF, QRectF, Qt)
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent):
super(Viewer, self).__init__(parent)
self._scene = QtWidgets.QGraphicsScene(self)
self.photo = QtWidgets.QGraphicsPixmapItem()
self.label = QtWidgets.QGraphicsPixmapItem()
self._scene.addItem(self.photo)
self._scene.addItem(self.label)
self.setScene(self._scene)
def overlayMaps(self):
blue = QtGui.QPixmap(600, 600)
blue.fill(QtGui.QColor(0,0,255,0))
p = QPainter(blue)
self.pen = QPen()
self.pen.setColor(QtGui.QColor(0,0,255,255))
self.pen.setWidth(10)
p.setPen(self.pen)
p.drawLine(0,0,600,600)
green = QtGui.QPixmap(600, 600)
green.fill(QtGui.QColor(0,255,0,0))
p = QPainter(green)
self.pen = QPen()
self.pen.setColor(QtGui.QColor(0,255,0,255))
self.pen.setWidth(10)
p.setPen(self.pen)
p.drawLine(600,0,0,600)
self.photo.setPixmap(blue)
self.label.setPixmap(green)
resultPixmap = QtGui.QPixmap(self.photo.pixmap().width(), self.photo.pixmap().height())
# resultPainter = QtGui.QPainter(resultPixmap)
# resultPainter.setCompositionMode(QtGui.QPainter.CompositionMode_SourceOver)
# resultPainter.drawPixmap(300,300, self.photo.pixmap())
# resultPainter.drawPixmap(300,300, self.label.pixmap())
def saveOverlayMap(self):
pass
class Window(QtWidgets.QWidget):
def __init__(self):
super(Window, self).__init__()
self.viewer = Viewer(self)
self.viewer.overlayMaps()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Window()
window.setGeometry(500, 300, 600, 600)
window.show()
sys.exit(app.exec_())
python pyqt pyqt5 qpainter qpixmap
python pyqt pyqt5 qpainter qpixmap
edited Nov 21 '18 at 23:01
eyllanesc
77.8k103156
asked Nov 21 '18 at 21:38
CSforStructuralEngineerCSforStructuralEngineer
687
edited Nov 21 '18 at 23:01
eyllanesc
77.8k103156
asked Nov 21 '18 at 21:38
CSforStructuralEngineerCSforStructuralEngineer
687
edited Nov 21 '18 at 23:01
eyllanesc
77.8k103156
edited Nov 21 '18 at 23:01
eyllanesc
77.8k103156
edited Nov 21 '18 at 23:01
eyllanesc
77.8k103156
77.8k103156
asked Nov 21 '18 at 21:38
CSforStructuralEngineerCSforStructuralEngineer
687
asked Nov 21 '18 at 21:38
CSforStructuralEngineerCSforStructuralEngineer
687
asked Nov 21 '18 at 21:38
CSforStructuralEngineerCSforStructuralEngineer
687
687
both items have the same pixmap, do not you think that's wrong?
– eyllanesc
Nov 21 '18 at 22:13
The code snippet is just to illustrate the issue. In my full code, the pixmaps are different.
– CSforStructuralEngineer
Nov 21 '18 at 22:14
you could then show that in your question, you can place both pixmaps in your question
– eyllanesc
Nov 21 '18 at 22:15
Okay, edited the question and code
– CSforStructuralEngineer
Nov 21 '18 at 22:18
1
I have already published a solution, hopefully what you are looking for. On the other hand now his example is much better, even if it is a trivial example his code must be a Minimal, Complete, and Verifiable example, that is, something that allows us to take as a basis to try to provide you with a solution. :-)
– eyllanesc
Nov 21 '18 at 22:54
|
show 3 more comments
both items have the same pixmap, do not you think that's wrong?
– eyllanesc
Nov 21 '18 at 22:13
The code snippet is just to illustrate the issue. In my full code, the pixmaps are different.
– CSforStructuralEngineer
Nov 21 '18 at 22:14
you could then show that in your question, you can place both pixmaps in your question
– eyllanesc
Nov 21 '18 at 22:15
Okay, edited the question and code
– CSforStructuralEngineer
Nov 21 '18 at 22:18
1
I have already published a solution, hopefully what you are looking for. On the other hand now his example is much better, even if it is a trivial example his code must be a Minimal, Complete, and Verifiable example, that is, something that allows us to take as a basis to try to provide you with a solution. :-)
– eyllanesc
Nov 21 '18 at 22:54
both items have the same pixmap, do not you think that's wrong?
– eyllanesc
Nov 21 '18 at 22:13
both items have the same pixmap, do not you think that's wrong?
– eyllanesc
Nov 21 '18 at 22:13
The code snippet is just to illustrate the issue. In my full code, the pixmaps are different.
– CSforStructuralEngineer
Nov 21 '18 at 22:14
The code snippet is just to illustrate the issue. In my full code, the pixmaps are different.
– CSforStructuralEngineer
Nov 21 '18 at 22:14
you could then show that in your question, you can place both pixmaps in your question
– eyllanesc
Nov 21 '18 at 22:15
you could then show that in your question, you can place both pixmaps in your question
– eyllanesc
Nov 21 '18 at 22:15
Okay, edited the question and code
– CSforStructuralEngineer
Nov 21 '18 at 22:18
Okay, edited the question and code
– CSforStructuralEngineer
Nov 21 '18 at 22:18
1
1
I have already published a solution, hopefully what you are looking for. On the other hand now his example is much better, even if it is a trivial example his code must be a Minimal, Complete, and Verifiable example, that is, something that allows us to take as a basis to try to provide you with a solution. :-)
– eyllanesc
Nov 21 '18 at 22:54
I have already published a solution, hopefully what you are looking for. On the other hand now his example is much better, even if it is a trivial example his code must be a Minimal, Complete, and Verifiable example, that is, something that allows us to take as a basis to try to provide you with a solution. :-)
– eyllanesc
Nov 21 '18 at 22:54
|
show 3 more comments
1 Answer
1
active
oldest
votes
2
I have implemented a function that performs the action of joining depending on the mode, for a better appreciation I have moved the items.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
def join_pixmap(p1, p2, mode=QtGui.QPainter.CompositionMode_SourceOver):
s = p1.size().expandedTo(p2.size())
result = QtGui.QPixmap(s)
result.fill(QtCore.Qt.transparent)
painter = QtGui.QPainter(result)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
painter.drawPixmap(QtCore.QPoint(), p1)
painter.setCompositionMode(mode)
painter.drawPixmap(result.rect(), p2, p2.rect())
painter.end()
return result
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(Viewer, self).__init__(parent)
self._scene = QtWidgets.QGraphicsScene(self)
self.setScene(self._scene)
blue = QtGui.QPixmap(100, 100)
blue.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(blue)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0,0,255)), 10)
p.setPen(pen)
p.drawLine(0, 0, 100, 100)
p.end()
self.photo = self._scene.addPixmap(blue)
green = QtGui.QPixmap(100, 100)
green.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(green)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0, 255, 0, 255)), 10)
p.setPen(pen)
p.drawLine(100, 0, 0, 100)
p.end()
self.label = self._scene.addPixmap(green)
self.label.setPos(200, 0)
self.overlayMaps()
def overlayMaps(self):
p1 = QtGui.QPixmap(self.photo.pixmap())
p2 = QtGui.QPixmap(self.label.pixmap())
result_pixmap = join_pixmap(self.photo.pixmap(), self.label.pixmap())
self.result_item = self._scene.addPixmap(result_pixmap)
self.result_item.setPos(100, 200)
result_pixmap.save("result_pixmap.png")
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Viewer()
window.resize(640, 480)
window.show()
sys.exit(app.exec_())
result_pixmap.png
answered Nov 21 '18 at 22:50
eyllanesceyllanesc
77.8k103156
add a comment |
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1 Answer
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active
oldest
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1 Answer
1
active
oldest
votes
active
oldest
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active
oldest
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2
I have implemented a function that performs the action of joining depending on the mode, for a better appreciation I have moved the items.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
def join_pixmap(p1, p2, mode=QtGui.QPainter.CompositionMode_SourceOver):
s = p1.size().expandedTo(p2.size())
result = QtGui.QPixmap(s)
result.fill(QtCore.Qt.transparent)
painter = QtGui.QPainter(result)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
painter.drawPixmap(QtCore.QPoint(), p1)
painter.setCompositionMode(mode)
painter.drawPixmap(result.rect(), p2, p2.rect())
painter.end()
return result
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(Viewer, self).__init__(parent)
self._scene = QtWidgets.QGraphicsScene(self)
self.setScene(self._scene)
blue = QtGui.QPixmap(100, 100)
blue.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(blue)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0,0,255)), 10)
p.setPen(pen)
p.drawLine(0, 0, 100, 100)
p.end()
self.photo = self._scene.addPixmap(blue)
green = QtGui.QPixmap(100, 100)
green.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(green)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0, 255, 0, 255)), 10)
p.setPen(pen)
p.drawLine(100, 0, 0, 100)
p.end()
self.label = self._scene.addPixmap(green)
self.label.setPos(200, 0)
self.overlayMaps()
def overlayMaps(self):
p1 = QtGui.QPixmap(self.photo.pixmap())
p2 = QtGui.QPixmap(self.label.pixmap())
result_pixmap = join_pixmap(self.photo.pixmap(), self.label.pixmap())
self.result_item = self._scene.addPixmap(result_pixmap)
self.result_item.setPos(100, 200)
result_pixmap.save("result_pixmap.png")
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Viewer()
window.resize(640, 480)
window.show()
sys.exit(app.exec_())
result_pixmap.png
answered Nov 21 '18 at 22:50
eyllanesceyllanesc
77.8k103156
add a comment |
2
I have implemented a function that performs the action of joining depending on the mode, for a better appreciation I have moved the items.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
def join_pixmap(p1, p2, mode=QtGui.QPainter.CompositionMode_SourceOver):
s = p1.size().expandedTo(p2.size())
result = QtGui.QPixmap(s)
result.fill(QtCore.Qt.transparent)
painter = QtGui.QPainter(result)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
painter.drawPixmap(QtCore.QPoint(), p1)
painter.setCompositionMode(mode)
painter.drawPixmap(result.rect(), p2, p2.rect())
painter.end()
return result
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(Viewer, self).__init__(parent)
self._scene = QtWidgets.QGraphicsScene(self)
self.setScene(self._scene)
blue = QtGui.QPixmap(100, 100)
blue.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(blue)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0,0,255)), 10)
p.setPen(pen)
p.drawLine(0, 0, 100, 100)
p.end()
self.photo = self._scene.addPixmap(blue)
green = QtGui.QPixmap(100, 100)
green.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(green)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0, 255, 0, 255)), 10)
p.setPen(pen)
p.drawLine(100, 0, 0, 100)
p.end()
self.label = self._scene.addPixmap(green)
self.label.setPos(200, 0)
self.overlayMaps()
def overlayMaps(self):
p1 = QtGui.QPixmap(self.photo.pixmap())
p2 = QtGui.QPixmap(self.label.pixmap())
result_pixmap = join_pixmap(self.photo.pixmap(), self.label.pixmap())
self.result_item = self._scene.addPixmap(result_pixmap)
self.result_item.setPos(100, 200)
result_pixmap.save("result_pixmap.png")
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Viewer()
window.resize(640, 480)
window.show()
sys.exit(app.exec_())
result_pixmap.png
answered Nov 21 '18 at 22:50
eyllanesceyllanesc
77.8k103156
add a comment |
2
2
2
I have implemented a function that performs the action of joining depending on the mode, for a better appreciation I have moved the items.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
def join_pixmap(p1, p2, mode=QtGui.QPainter.CompositionMode_SourceOver):
s = p1.size().expandedTo(p2.size())
result = QtGui.QPixmap(s)
result.fill(QtCore.Qt.transparent)
painter = QtGui.QPainter(result)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
painter.drawPixmap(QtCore.QPoint(), p1)
painter.setCompositionMode(mode)
painter.drawPixmap(result.rect(), p2, p2.rect())
painter.end()
return result
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(Viewer, self).__init__(parent)
self._scene = QtWidgets.QGraphicsScene(self)
self.setScene(self._scene)
blue = QtGui.QPixmap(100, 100)
blue.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(blue)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0,0,255)), 10)
p.setPen(pen)
p.drawLine(0, 0, 100, 100)
p.end()
self.photo = self._scene.addPixmap(blue)
green = QtGui.QPixmap(100, 100)
green.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(green)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0, 255, 0, 255)), 10)
p.setPen(pen)
p.drawLine(100, 0, 0, 100)
p.end()
self.label = self._scene.addPixmap(green)
self.label.setPos(200, 0)
self.overlayMaps()
def overlayMaps(self):
p1 = QtGui.QPixmap(self.photo.pixmap())
p2 = QtGui.QPixmap(self.label.pixmap())
result_pixmap = join_pixmap(self.photo.pixmap(), self.label.pixmap())
self.result_item = self._scene.addPixmap(result_pixmap)
self.result_item.setPos(100, 200)
result_pixmap.save("result_pixmap.png")
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Viewer()
window.resize(640, 480)
window.show()
sys.exit(app.exec_())
result_pixmap.png
answered Nov 21 '18 at 22:50
eyllanesceyllanesc
77.8k103156
I have implemented a function that performs the action of joining depending on the mode, for a better appreciation I have moved the items.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
def join_pixmap(p1, p2, mode=QtGui.QPainter.CompositionMode_SourceOver):
s = p1.size().expandedTo(p2.size())
result = QtGui.QPixmap(s)
result.fill(QtCore.Qt.transparent)
painter = QtGui.QPainter(result)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
painter.drawPixmap(QtCore.QPoint(), p1)
painter.setCompositionMode(mode)
painter.drawPixmap(result.rect(), p2, p2.rect())
painter.end()
return result
class Viewer(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super(Viewer, self).__init__(parent)
self._scene = QtWidgets.QGraphicsScene(self)
self.setScene(self._scene)
blue = QtGui.QPixmap(100, 100)
blue.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(blue)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0,0,255)), 10)
p.setPen(pen)
p.drawLine(0, 0, 100, 100)
p.end()
self.photo = self._scene.addPixmap(blue)
green = QtGui.QPixmap(100, 100)
green.fill(QtCore.Qt.transparent)
p = QtGui.QPainter(green)
pen = QtGui.QPen(QtGui.QBrush(QtGui.QColor(0, 255, 0, 255)), 10)
p.setPen(pen)
p.drawLine(100, 0, 0, 100)
p.end()
self.label = self._scene.addPixmap(green)
self.label.setPos(200, 0)
self.overlayMaps()
def overlayMaps(self):
p1 = QtGui.QPixmap(self.photo.pixmap())
p2 = QtGui.QPixmap(self.label.pixmap())
result_pixmap = join_pixmap(self.photo.pixmap(), self.label.pixmap())
self.result_item = self._scene.addPixmap(result_pixmap)
self.result_item.setPos(100, 200)
result_pixmap.save("result_pixmap.png")
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
window = Viewer()
window.resize(640, 480)
window.show()
sys.exit(app.exec_())
result_pixmap.png
answered Nov 21 '18 at 22:50
eyllanesceyllanesc
77.8k103156
answered Nov 21 '18 at 22:50
eyllanesceyllanesc
77.8k103156
answered Nov 21 '18 at 22:50
eyllanesceyllanesc
77.8k103156
answered Nov 21 '18 at 22:50
eyllanesceyllanesc
77.8k103156
77.8k103156
add a comment |
add a comment |
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both items have the same pixmap, do not you think that's wrong?
– eyllanesc
Nov 21 '18 at 22:13
The code snippet is just to illustrate the issue. In my full code, the pixmaps are different.
– CSforStructuralEngineer
Nov 21 '18 at 22:14
you could then show that in your question, you can place both pixmaps in your question
– eyllanesc
Nov 21 '18 at 22:15
Okay, edited the question and code
– CSforStructuralEngineer
Nov 21 '18 at 22:18
1
I have already published a solution, hopefully what you are looking for. On the other hand now his example is much better, even if it is a trivial example his code must be a Minimal, Complete, and Verifiable example, that is, something that allows us to take as a basis to try to provide you with a solution. :-)
– eyllanesc
Nov 21 '18 at 22:54