diff --git a/Model/ImageWriter.py b/Model/ImageWriter.py
index 9852523..4fdf7fc 100644
--- a/Model/ImageWriter.py
+++ b/Model/ImageWriter.py
@@ -1,18 +1,128 @@
 from iptcinfo3 import IPTCInfo
+import os
+import exiv2
 
 class ImageWriter:
-    def writeTagsFromPredictionsInImages(self, predictions):
+
+    _max_bytes = {
+        'Iptc.Application2.Byline'             :   32,
+        'Iptc.Application2.BylineTitle'        :   32,
+        'Iptc.Application2.Caption'            : 2000,
+        'Iptc.Application2.City'               :   32,
+        'Iptc.Application2.Contact'            :  128,
+        'Iptc.Application2.Copyright'          :  128,
+        'Iptc.Application2.CountryCode'        :    3,
+        'Iptc.Application2.CountryName'        :   64,
+        'Iptc.Application2.Credit'             :   32,
+        'Iptc.Application2.Headline'           :  256,
+        'Iptc.Application2.Keywords'           :   64,
+        'Iptc.Application2.ObjectName'         :   64,
+        'Iptc.Application2.Program'            :   32,
+        'Iptc.Application2.ProgramVersion'     :   10,
+        'Iptc.Application2.ProvinceState'      :   32,
+        'Iptc.Application2.SpecialInstructions':  256,
+        'Iptc.Application2.SubLocation'        :   32,
+        'Iptc.Envelope.CharacterSet'           :   32,
+        }
+
+
+    def changeToRawExtension(self, file_path, newExtension):
+        base_path, extension = os.path.splitext(file_path)
+        raw_file_path = base_path + "." + newExtension
+        return raw_file_path
+    
+    @classmethod
+    def truncate_iptc(cls, tag, value):
+        if tag in cls._max_bytes:
+            value = value.encode('utf-8')[:cls._max_bytes[tag]]
+            value = value.decode('utf-8', errors='ignore')
+        return value
+
+    def set_iptc_value(self, iptcData, tag, value):
+        if not value:
+            self.clear_iptc_tag(tag)
+            return
+        # make list of values
+        key = exiv2.IptcKey(tag)
+        type_id = exiv2.IptcDataSets.dataSetType(key.tag(), key.record())
+        if type_id == exiv2.TypeId.date:
+            values = [exiv2.DateValue(*value)]
+        elif type_id == exiv2.TypeId.time:
+            values = [exiv2.TimeValue(*value)]
+        elif isinstance(value, (list, tuple)):
+            values = [self.truncate_iptc(tag, x) for x in value]
+        else:
+            values = [self.truncate_iptc(tag, value)]
+        # update or delete existing values
+        datum = iptcData.findKey(key)
+        while datum != iptcData.end():
+            if datum.key() == tag:
+                if values:
+                    datum.setValue(values.pop(0))
+                else:
+                    datum = iptcData.erase(datum)
+                    continue
+            next(datum)
+        # append remaining values
+        while values:
+            datum = exiv2.Iptcdatum(key)
+            datum.setValue(values.pop(0))
+            if iptcData.add(datum) != 0:
+                print('duplicated tag %s', tag)
+                return
+        return iptcData
+    
+    def writeTagsFromPredictionsInImages(self, predictions, applyToRaw, overwrite):
+        startApplyToRaw = applyToRaw
         for data in predictions:
+            applyToRaw = startApplyToRaw
             filename = data[0]
+            filenameRaw = None
             prediction = data[1]
 
             iptcInfo = IPTCInfo(filename, force=True)
+            iptcInfoRaw = None
+            if applyToRaw:
+                extensions = ['dng','DNG']
+                for extension in extensions:
+                    filenameRaw = self.changeToRawExtension(filename, extension)
+                    if os.path.exists(filenameRaw):
+                        iptcInfoRaw = exiv2.ImageFactory.open(filenameRaw)
+                        iptcInfoRaw.readMetadata()
+                        break
+                applyToRaw = iptcInfoRaw != None                
+            
+            addedKeywords = []
+
+            if overwrite:
+                iptcInfo['keywords'] = []
 
             if prediction.m_label not in iptcInfo['keywords']: 
                 iptcInfo['keywords'].append(prediction.m_label)
+                addedKeywords.append(prediction.m_label)
             
             for category in prediction.m_categories:
                 if category not in iptcInfo['keywords']:
                     iptcInfo['keywords'].append(category)
+                    addedKeywords.append(category)       
+
+            try:
+                iptcInfo.save()
+                tempFilename = filename + "~"
+                if os.path.exists(tempFilename):
+                    os.remove(tempFilename)
+            except Exception as e:
+                print('Error in file "'+filename+'" : \n\t', e)
+
+            if applyToRaw:
+                try:
+                    separator = '; '
+                    iptcData = iptcInfoRaw.iptcData()
+                    iptcData = self.set_iptc_value(iptcData, 'Iptc.Envelope.CharacterSet', '\x1b%G')
+                    iptcData = self.set_iptc_value(iptcData,"Iptc.Application2.Keywords",addedKeywords)
+                    iptcInfoRaw.setIptcData(iptcData)
+                    iptcInfoRaw.writeMetadata()
+                except Exception as e:
+                    print('Error in file "'+filenameRaw+'" : \n\t', e)     
 
-            iptcInfo.save()
\ No newline at end of file
+            
\ No newline at end of file
diff --git a/UI/MainWindow.py b/UI/MainWindow.py
index 9471c6e..8c5b051 100644
--- a/UI/MainWindow.py
+++ b/UI/MainWindow.py
@@ -15,6 +15,8 @@ def __init__(self, parent=None):
         # UI
         self.m_loadFileButton = QtWidgets.QPushButton("Load files...")
         self.m_classifyImageButton = QtWidgets.QPushButton("Classify images")
+        self.m_writeTagsCheckBox = QtWidgets.QCheckBox("Apply to DNG")
+        self.m_overwriteTagsCheckBox = QtWidgets.QCheckBox("Overwrite tags")
         self.m_writeTagsButton = QtWidgets.QPushButton("Write tags in images")
 
         self.m_fileNamesPlainTextEdit = QtWidgets.QPlainTextEdit("No files loaded...")
@@ -31,8 +33,14 @@ def __init__(self, parent=None):
         self.layout = QtWidgets.QVBoxLayout(self)
         self.layout.addWidget(self.m_loadFileButton)
         self.layout.addWidget(self.m_fileNamesPlainTextEdit)
-        self.layout.addWidget(self.m_classifyImageButton)
+        self.layout.addWidget(self.m_classifyImageButton)       
         self.layout.addWidget(self.m_resultTable)
+
+        buttonLayout = QtWidgets.QHBoxLayout()
+        buttonLayout.addWidget(self.m_writeTagsCheckBox)
+        buttonLayout.addWidget(self.m_overwriteTagsCheckBox)
+        self.layout.addLayout(buttonLayout)
+
         self.layout.addWidget(self.m_writeTagsButton)
 
         self.m_loadFileButton.clicked.connect(self.onLoadFileButtonClicked)
@@ -59,5 +67,7 @@ def onClassifyImageButtonClicked(self):
     @QtCore.Slot()
     def onWriteTagsButtonClicked(self):
         lastPredictions = self.m_predictionModel.getLastPredictions()
-        self.m_imageWriter.writeTagsFromPredictionsInImages(lastPredictions)
+        applyToRaw = self.m_writeTagsCheckBox.isChecked()
+        overwrite = self.m_overwriteTagsCheckBox.isChecked()
+        self.m_imageWriter.writeTagsFromPredictionsInImages(lastPredictions, applyToRaw, overwrite)
         
\ No newline at end of file