diff --git a/pixelocr/gui/__init__.py b/pixelocr/gui/__init__.py
index 315605e..cb0847f 100644
--- a/pixelocr/gui/__init__.py
+++ b/pixelocr/gui/__init__.py
@@ -16,17 +16,22 @@
 
 import sys
 import signal
+from threading import Thread
 
 import sip
 sip.setapi('QString', 2)
 
-from .window import MainWindow
-
+from PyQt4 import QtCore
+QtCore.signal = QtCore.pyqtSignal
+QtCore.slot = QtCore.pyqtSlot
 
 from PyQt4.QtGui import (
     QApplication,
 )
 
+from .window import MainWindow
+from .ocrengine import OCREngine
+
 
 def main():
     app = QApplication(sys.argv)
@@ -37,9 +42,11 @@ def main():
     win = MainWindow()
     win.show()
 
-    from ..page import Page
-    from ..image import Image
-    win.pageScene.setPage(Page(Image.fromfile(sys.argv[1]).unframe(10)))
+    ocr = OCREngine(sys.argv[1:])
+    ocr.pageChanged.connect(win.pageScene.setPage)
+    ocr.unknownLetter.connect(win.unknownLetter)
+    win.letterEntered.connect(ocr.give_help)
+    ocr.start()
 
     signal.signal(signal.SIGINT, signal.SIG_DFL)
     sys.exit(app.exec_())
diff --git a/pixelocr/gui/pageview.py b/pixelocr/gui/pageview.py
index 3671f1b..d0fe025 100644
--- a/pixelocr/gui/pageview.py
+++ b/pixelocr/gui/pageview.py
@@ -14,12 +14,17 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-from PyQt4.QtCore import Qt
+from PyQt4.QtCore import (
+    signal,
+    slot,
+)
+
 from PyQt4.QtGui import (
     QBrush,
     QColor,
     QFrame,
     QGraphicsDropShadowEffect,
+    QGraphicsItem,
     QGraphicsScene,
     QGraphicsView,
     QImage,
@@ -45,11 +50,21 @@ class PageScene(QGraphicsScene):
     page = None
     pageItem = None
 
+    letterPen = QColor(0, 0, 0, 80)
+    letterBrush = QColor(255, 255, 0, 80)
+    spacePen = QColor(0, 0, 0, 80)
+    spaceBrush = QColor(0, 0, 255, 20)
+    linePen = QColor(255, 50, 50, 100)
+
+    pageItemChanged = signal([QGraphicsItem])
+
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
+        self.highlightedLetters = {}
         self.setBackgroundBrush(self.palette().window())
 
     def setPage(self, page):
+        self.highlightedLetters.clear()
         for item in self.items():
             self.remoteItem(item)
         self.page = page
@@ -59,27 +74,36 @@ class PageScene(QGraphicsScene):
         shadow.setBlurRadius(20)
         shadow.setOffset(2, 2)
         self.pageItem.setGraphicsEffect(shadow)
+        self.pageItemChanged.emit(self.pageItem)
 
-        letterPen = QColor(0, 0, 0, 80)
-        letterBrush = QColor(255, 255, 0, 80)
-        spacePen = QColor(0, 0, 0, 80)
-        spaceBrush = QColor(0, 0, 255, 20)
-        linePen = QColor(255, 50, 50, 100)
+    def highlightAll(self):
         for line in page:
             for letter in line:
                 if not letter.image.isspace:
-                    self.addRect(letter.x - 1, letter.y - 1, letter.width + 1, letter.height + 1, letterPen, letterBrush)
+                    self.addRect(letter.x - 1, letter.y - 1, letter.width + 1, letter.height + 1, self.letterPen, self.letterBrush)
                 else:
-                    self.addRect(letter.x - 1, letter.y - 1, letter.width + 1, letter.height + 1, spacePen, spaceBrush)
-            self.addLine(line.left, line.baseline, line.right, line.baseline, linePen)
+                    self.addRect(letter.x - 1, letter.y - 1, letter.width + 1, letter.height + 1, self.spacePen, self.spaceBrush)
+            self.addLine(line.left, line.baseline, line.right, line.baseline, self.linePen)
 
     def addPage(self, page):
         qimage = ndimage2qimage(page.image.data)
         graphicsitem = self.addPixmap(QPixmap.fromImage(qimage))
         return graphicsitem
 
+    def highlightLetter(self, letter):
+        rect = self.addRect(letter.x - 1, letter.y - 1, letter.width + 1, letter.height + 1, self.letterPen, self.letterBrush)
+        self.highlightedLetters[letter] = rect
+
+    def clearHighlight(self):
+        for item in self.highlightedLetters.values():
+            self.removeItem(item)
+        self.highlightedLetters.clear()
+
 
 class PageView(QGraphicsView):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.setFrameShape(self.NoFrame)
+
+    def centerOnPage(self, pageItem):
+        self.centerOn(pageItem)
diff --git a/pixelocr/gui/window.py b/pixelocr/gui/window.py
index 09ece52..cff172f 100644
--- a/pixelocr/gui/window.py
+++ b/pixelocr/gui/window.py
@@ -15,6 +15,8 @@
 
 
 from PyQt4.QtCore import (
+    signal,
+    slot,
     Qt,
     QSettings,
     QSize,
@@ -28,9 +30,12 @@ from PyQt4.QtGui import (
 )
 
 from .pageview import PageScene, PageView
+from .glyphedit import GlyphEdit
 
 
 class MainWindow(QMainWindow):
+    letterEntered = signal([str])
+
     def __init__(self):
         super().__init__()
         self.setWindowTitle('PixelOCR')
@@ -39,10 +44,16 @@ class MainWindow(QMainWindow):
         self.setCentralWidget(centralWidget)
         self.pageScene = PageScene(self)
         self.page = PageView(self.pageScene, centralWidget)
+        self.pageScene.pageItemChanged.connect(self.page.centerOnPage)
+        self.glyphEdit = GlyphEdit(centralWidget)
+        self.glyphEdit.letterEntered.connect(self.letterEntered)
+        self.glyphEdit.letterEntered.connect(self.pageScene.clearHighlight)
 
         layout = QVBoxLayout(centralWidget)
-        layout.addWidget(self.page)
+        layout.setSpacing(0)
         layout.setContentsMargins(0, 0, 0, 0)
+        layout.addWidget(self.page)
+        layout.addWidget(self.glyphEdit)
 
         self.readSettings()
 
@@ -63,3 +74,8 @@ class MainWindow(QMainWindow):
         self.restoreGeometry(settings.value("windowGeometry") or b'')
         self.restoreState(settings.value("windowState") or b'')
 
+    def unknownLetter(self, letter):
+        self.pageScene.highlightLetter(letter)
+        self.glyphEdit.setEnabled(True)
+        self.glyphEdit.text.clear()
+        self.glyphEdit.text.setFocus()