Set a png icon for linux compatitlity

artemis.py

@@ -59,7 +59,6 @@ class Artemis(QMainWindow, Ui_MainWindow):
         super().__init__()
         self.setupUi(self)
         self.set_initial_size()
-        self.setWindowIcon(QtGui.QIcon(":/icon/default_pics/Artemis3.500px.png"))  # TODO: Not clear if necessary.
         self.closing = False
         self.download_window = DownloadWindow()
         self.download_window.complete.connect(self.show_downloaded_signals)
@@ -1594,9 +1593,8 @@ class Artemis(QMainWindow, Ui_MainWindow):
 
 if __name__ == '__main__':
     my_app = QApplication(sys.argv)
-    img = QPixmap(os.path.join(
-        ":", "icon", "default_pics", "Artemis3.500px.png")
-    )
+    ARTEMIS_ICON = os.path.join(":", "icon", "default_pics", "Artemis3.500px.png")
+    img = QPixmap(ARTEMIS_ICON)
     splash = QSplashScreen(img)
     splash.show()
     start= time()

artemis.ui

@@ -21,7 +21,7 @@
   </property>
   <property name="windowIcon">
    <iconset resource="default_imgs.qrc">
-    <normaloff>:/icon/default_pics/Artemis3.ico</normaloff>:/icon/default_pics/Artemis3.ico</iconset>
+    <normaloff>:/icon/default_pics/Artemis3.500px.png</normaloff>:/icon/default_pics/Artemis3.500px.png</iconset>
   </property>
   <property name="styleSheet">
    <string notr="true"/>

default_imgs.qrc

@@ -1,8 +1,6 @@
 <RCC>
   <qresource prefix="icon">
     <file>default_pics/Artemis3.500px.png</file>
-    <file>default_pics/Artemis3.ico</file>
-    <file>default_pics/Artemis3.png</file>
   </qresource>
   <qresource prefix="pics">
     <file>default_pics/nosignalselected.png</file>

download_db_window.ui

@@ -15,7 +15,7 @@
   </property>
   <property name="windowIcon">
    <iconset resource="default_imgs.qrc">
-    <normaloff>:/icon/default_pics/Artemis3.ico</normaloff>:/icon/default_pics/Artemis3.ico</iconset>
+    <normaloff>:/icon/default_pics/Artemis3.500px.png</normaloff>:/icon/default_pics/Artemis3.500px.png</iconset>
   </property>
   <property name="styleSheet">
    <string notr="true"/>