main.py

'''
A simple player that mixes the Pi camera output with the mlx90640 thermal
camera output into one stream.  Each capture is run in its own thread and
their outputs (received using Signal/Slot mechanism) are combined in the
player thread. The refersh happends on the receiver of the Pi camera since
it has a faster capture rate. A mutex is used to serialize access to thermal
image pixmap.
'''
import sys
import threading

from PyQt5.QtWidgets import  QWidget, QLabel, QApplication
from PyQt5.QtCore import QThread, Qt, pyqtSignal, pyqtSlot, QPoint
from PyQt5.QtGui import QPixmap, QPainter

from pixread import VidThread
from mlxread import MLXThread

class ThermalPlayer(QWidget):
    def __init__(self):
        super().__init__()
        self.title = 'Thermal Cam'
        self.left = 50
        self.top = 50
        self.leftmargin = 100
        self.topmargin = 50
        self.width = 640
        self.height = 480
        self.heatpix = QPixmap(640,480)
        self.heatpix.fill(Qt.transparent)
        self.campix = None
        self.heatpixlock = threading.Lock()
        self.initUI()


    @pyqtSlot(QPixmap)
    def setImage(self, pixmap):
        # Currently campix isn't used, but if used
        # it needs to be deep copied.
        self.campix = pixmap.copy()

        # Image compositing
        dispix = pixmap
        painter = QPainter(dispix)
        painter.setRenderHint(QPainter.Antialiasing)
        # painter.setCompositionMode(QPainter.CompositionMode_Plus)
        painter.setCompositionMode(QPainter.CompositionMode_Screen)
        # painter.setCompositionMode(QPainter.CompositionMode_HardLight)
        # painter.setCompositionMode(QPainter.CompositionMode_SourceAtop)

        # setHeat callback also accesses heatpix
        with self.heatpixlock:
            painter.drawPixmap(QPoint(), self.heatpix)
        painter.end()

        self.label.setPixmap(dispix)


    @pyqtSlot(QPixmap)
    def setHeat(self, pixmap):
        # setImage callback also accesses heatpix
        with self.heatpixlock:
            self.heatpix = pixmap.copy()


    def initUI(self):
        self.setWindowTitle(self.title)
        self.setGeometry(self.left, self.top, self.width, self.height)
        self.resize(self.width+2*self.leftmargin,self.height+2*self.topmargin)

        self.label = QLabel(self)
        self.label.move(self.leftmargin,self.topmargin)
        self.label.resize(self.width, self.height)

        self.show()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    myapp = ThermalPlayer()

    print("Video Thread")
    vthread = QThread()
    vthread.start()
    vth = VidThread()
    vth.width = myapp.width
    vth.height = myapp.height
    vth.mirror = True
    vth.changePixmap.connect(myapp.setImage)
    vth.moveToThread(vthread)
    vth.go.emit()

    print("MLX Thread")
    mlxthread = QThread()
    mlxthread.start()
    mlxt = MLXThread()
    mlxt.changeHeatmap.connect(myapp.setHeat)
    mlxt.moveToThread(mlxthread)
    mlxt.go.emit()

    sys.exit(app.exec_())