Macro Image Scaling

Description
Macro for easy scaling of drawings, graphics, diagrams, blueprints and similar 2D images in the Image workbench. It works for images imported as planar images in the 3D space.

Note: For photos of objects, or images involving objects lying at different distances from the viewpoint, the effect of Parallax (distortion due to "difference in the apparent position of an object viewed along two different lines of sight") must be kept in mind. In the following diagram the 2 blue objects are co-planar with the plane being perpendicular to the user viewpoint and scaling can be used:



In the second diagram, the red and green objects are not co-planar with the 2 blue objects and scaling can not be used. Additionally the fact that the red object is co-planar with 1 blue object can not be determined from the single diagram based on the user viewpoint:



Use

 * run the Macro - a dialogue pops up
 * click on the two points in the image that you know the true distance between
 * Select the Image Plane in the tree view
 * Enter the true distance in mm between the points in the text field of the dialogue and click OK
 * The image is scaled and the dialogue closes.

Script
QtGui.QDialogButtonBox.Ok)      self.buttonBox.setObjectName(_fromUtf8("buttonBox"))        self.buttonBox.button(QtGui.QDialogButtonBox.Ok).setEnabled(False)        self.label = QtGui.QLabel(Dialog)        self.label.setGeometry(QtCore.QRect(30, 10, 66, 17))        self.label.setObjectName(_fromUtf8("label"))        self.lineEdit = QtGui.QLineEdit(Dialog)        self.lineEdit.setGeometry(QtCore.QRect(100, 10, 113, 29))        self.lineEdit.setObjectName(_fromUtf8("lineEdit"))        self.label1 = QtGui.QLabel(Dialog)        self.label1.setGeometry(QtCore.QRect(20, 45, 260, 17))        self.label1.setObjectName(_fromUtf8("label1"))        self.retranslateUi(Dialog)        QtCore.QObject.connect(self.buttonBox, QtCore.SIGNAL(_fromUtf8("accepted")), self.accept)        QtCore.QObject.connect(self.buttonBox, QtCore.SIGNAL(_fromUtf8("rejected")), self.reject)        QtCore.QMetaObject.connectSlotsByName(Dialog) self.tracker = DraftTrackers.lineTracker(scolor=(1,0,0)) self.tracker.raiseTracker self.tracker.on       self.dialog.show

def retranslateUi(self, Dialog): Dialog.setWindowTitle(_translate("Dialog", "Dialog", None)) self.label.setText(_translate("Dialog", "Distance", None)) self.label1.setText(_translate("Dialog", "Select first point", None)) def accept(self): sel = FreeCADGui.Selection.getSelection try: locale=QtCore.QLocale.system d, ok = locale.toFloat(self.lineEdit.text) if not ok: raise ValueError s=d/self.distance sel[0].XSize.Value=sel[0].XSize.Value*s sel[0].YSize.Value=sel[0].YSize.Value*s FreeCAD.Console.PrintMessage("Scale="+str(s)) self.tracker.off self.tracker.finalize self.dialog.hide except ValueError, ZeroDivisionError: self.label1.setText(_translate("Dialog", "Enter distance ", None)) return except IndexError, AttributeError: self.label1.setText(_translate("Dialog", "Select ImagePlane ", None)) return def reject(self): self.stack=[] self.view.removeEventCallbackPivy(pvy.SoMouseButtonEvent.getClassTypeId,self.callback) self.view.removeEventCallbackPivy(pvy.SoLocation2Event.getClassTypeId,self.callmouse) self.tracker.off self.tracker.finalize self.dialog.hide def getmousepoint(self, event_cb): event = event_cb.getEvent if len(self.stack)==1: pos = event.getPosition point = self.view.getPoint(pos[0],pos[1]) self.tracker.p2(point) def getpoint(self,event_cb): event = event_cb.getEvent if event.getState == pvy.SoMouseButtonEvent.DOWN: pos = event.getPosition point = self.view.getPoint(pos[0],pos[1]) self.stack.append(point) self.label1.setText(_translate("Dialog", "Select second point", None)) if len(self.stack)==1: self.tracker.p1(point) elif len(self.stack) == 2: self.distance=distance(self.stack[0], self.stack[1]) self.tracker.p2(point) self.view.removeEventCallbackPivy(pvy.SoMouseButtonEvent.getClassTypeId,self.callback) self.view.removeEventCallbackPivy(pvy.SoLocation2Event.getClassTypeId,self.callmouse) self.buttonBox.button(QtGui.QDialogButtonBox.Ok).setEnabled(True) self.label1.setText(_translate("Dialog", "Select Image Plane and type distance", None)) d = QtGui.QWidget ui = Ui_Dialog ui.setupUi(d)
 * 1) Init

Links

 * [Forum discussion]
 * [Download zip]
 * [Movie created by microelly2]