Bug 61950 [Markers] Images being created twice potentially
org.eclipse.ui.views.internal is using a static called ImageFactory which has it's own ImageRegistry. It should use JFaceResources.getImageRegistry to be sure that images are not being created twice (Image creation can be very expensive). I am not sure that this is a problem currently with performance but it could add to start up time.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/FieldDone.java
if (obj == null || !(obj instanceof TaskMarker)) {
            return null;
        }
        TaskMarker marker = (TaskMarker) obj;
        int done = marker.getDone();
        if (done == -1) {
            return null;
        }
        if (done == 1) {
            return ImageFactory.getImage(COMPLETE_IMAGE_PATH);
        }
        return ImageFactory.getImage(INCOMPLETE_IMAGE_PATH);
    }
    /*
     *  (non-Javadoc)
     * @see org.eclipse.ui.views.markers.internal.IField#compare(java.lang.Object, java.lang.Object)
     */
    public int compare(Object obj1, Object obj2) {
        if (obj1 == null || obj2 == null || !(obj1 instanceof TaskMarker)
                || !(obj2 instanceof TaskMarker)) {
            return 0;
        }
        TaskMarker marker1 = (TaskMarker) obj1;
        TaskMarker marker2 = (TaskMarker) obj2;
        int value1 = marker1.getDone();
        int value2 = marker2.getDone();
        return value1 - value2;
    }
}