Macro Image Scaling

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Text-x-python.png Image Scaling

Description
Scaling of drawings
Author
JAndersM
Links
Macros recipes
How to install macros
How to customize toolbars
Version
1.0
Date last modification
2016-01-19


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:

Perspective.png

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:

Parallax.jpg

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

import FreeCADGui, FreeCAD, Part
import math
import pivy.coin as pvy
from PySide import QtCore, QtGui
import DraftTrackers, Draft

__title__   = "Macro Image Scaling"
__author__  = "JAndersM"
__url__     = "http://www.freecadweb.org/index-fr.html"
__version__ = "00.01"
__date__    = "19/01/2016"

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

def distance(p1,p2):
    dx=p2[0]-p1[0]
    dy=p2[1]-p1[1]
    dz=p2[2]-p1[2]
    return math.sqrt(dx*dx+dy*dy+dz*dz)
    
class Ui_Dialog(object):
    def setupUi(self, Dialog):
        self.view = FreeCADGui.ActiveDocument.ActiveView
        self.stack = []
        self.callback = self.view.addEventCallbackPivy(pvy.SoMouseButtonEvent.getClassTypeId(),self.getpoint)
        self.callmouse=self.view.addEventCallbackPivy(pvy.SoLocation2Event.getClassTypeId(),self.getmousepoint)
        self.distance=0
        self.dialog=Dialog
        Dialog.setObjectName(_fromUtf8("Dialog"))
        Dialog.setWindowFlags(QtCore.Qt.WindowStaysOnTopHint)
        Dialog.resize(300, 102)
        self.buttonBox = QtGui.QDialogButtonBox(Dialog)
        self.buttonBox.setGeometry(QtCore.QRect(50, 70, 191, 32))
        self.buttonBox.setOrientation(QtCore.Qt.Horizontal)
        self.buttonBox.setStandardButtons(QtGui.QDialogButtonBox.Cancel.__or__(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", "<font color='red'>Enter distance</font>", None))
            return
        except IndexError, AttributeError:
            self.label1.setText(_translate("Dialog", "<font color='red'>Select ImagePlane</font>", 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))
                
#Init               
d = QtGui.QWidget()
ui = Ui_Dialog()
ui.setupUi(d) 

Links


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