diff --git a/native/src/defines_touch_position_correction.h b/native/src/defines_touch_position_correction.h
new file mode 100644
index 0000000..1229068
--- /dev/null
+++ b/native/src/defines_touch_position_correction.h
@@ -0,0 +1,61 @@
+/*
+**
+** Copyright 2011, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+#ifndef LATINIME_DEFINES_TOUCH_POSITION_CORRECTION_H
+#define LATINIME_DEFINES_TOUCH_POSITION_CORRECTION_H
+
+#define OUTER_SWEET_SPOT_RADIUS_RATIO 1.3
+
+static const char* TOUCH_POSITION_CORRECTION_GROUPS[] = {
+        "qwertyuiop",
+        "a",
+        "sdfghjk",
+        "l",
+        "zxcvbnm",
+};
+
+// (center X) / (key width)
+static const float RELATIVE_TOUCH_CENTER_X[] = {
+        0,          // qwertyuiop
+        -0.26871,   // a
+        0,          // sdfghjk
+        0.028050,   // l
+        0,          // zxcvbnm
+};
+
+// (center Y) / (key height)
+static const float RELATIVE_TOUCH_CENTER_Y[] = {
+        0.192088,   // qwertyuiop
+        0.214100,   // a
+        0.216640,   // sdfghjk
+        0.233288,   // l
+        0.286598,   // zxcvbnm
+};
+
+// (sweet spot radius) / ((key width) + (key height))
+static const float SWEET_SPOT_RADIUS[] = {
+        0.148955,   // qwertyuiop
+        0.185437,   // a
+        0.145522,   // sdfghjk
+        0.156882,   // l
+        0.144211,   // zxcvbnm
+};
+
+#define CORRECTION_GROUP_COUNT \
+    ((int)(sizeof(TOUCH_POSITION_CORRECTION_GROUPS) / sizeof(TOUCH_POSITION_CORRECTION_GROUPS[0])))
+
+#endif // LATINIME_DEFINES_TOUCH_POSITION_CORRECTION_H
diff --git a/native/src/proximity_info.cpp b/native/src/proximity_info.cpp
index 361bdac..94cccc3 100644
--- a/native/src/proximity_info.cpp
+++ b/native/src/proximity_info.cpp
@@ -14,11 +14,13 @@
  * limitations under the License.
  */
 
+#include <assert.h>
 #include <stdio.h>
 #include <string.h>
 
 #define LOG_TAG "LatinIME: proximity_info.cpp"
 
+#include "defines_touch_position_correction.h"
 #include "dictionary.h"
 #include "proximity_info.h"
 
@@ -26,17 +28,59 @@
 
 ProximityInfo::ProximityInfo(const int maxProximityCharsSize, const int keyboardWidth,
         const int keyboardHeight, const int gridWidth, const int gridHeight,
-        const uint32_t *proximityCharsArray)
+        const uint32_t *proximityCharsArray, const int keyCount, const int32_t *keyXCoordinates,
+        const int32_t *keyYCoordinates, const int32_t *keyWidths, const int32_t *keyHeights,
+        const int32_t *keyCharCodes)
         : MAX_PROXIMITY_CHARS_SIZE(maxProximityCharsSize), KEYBOARD_WIDTH(keyboardWidth),
           KEYBOARD_HEIGHT(keyboardHeight), GRID_WIDTH(gridWidth), GRID_HEIGHT(gridHeight),
           CELL_WIDTH((keyboardWidth + gridWidth - 1) / gridWidth),
-          CELL_HEIGHT((keyboardHeight + gridHeight - 1) / gridHeight) {
+          CELL_HEIGHT((keyboardHeight + gridHeight - 1) / gridHeight),
+          KEY_COUNT(min(keyCount, MAX_KEY_COUNT_IN_A_KEYBOARD)) {
     const int len = GRID_WIDTH * GRID_HEIGHT * MAX_PROXIMITY_CHARS_SIZE;
     mProximityCharsArray = new uint32_t[len];
     if (DEBUG_PROXIMITY_INFO) {
         LOGI("Create proximity info array %d", len);
     }
     memcpy(mProximityCharsArray, proximityCharsArray, len * sizeof(mProximityCharsArray[0]));
+
+    if (KEY_COUNT > 0) {
+        if (DEBUG_PROXIMITY_INFO) {
+            LOGI("Create key coordinate array %d", keyCount);
+        }
+        memcpy(mKeyXCoordinates, keyXCoordinates, KEY_COUNT * sizeof(mKeyXCoordinates[0]));
+        memcpy(mKeyYCoordinates, keyYCoordinates, KEY_COUNT * sizeof(mKeyYCoordinates[0]));
+        memcpy(mKeyWidths, keyWidths, KEY_COUNT * sizeof(mKeyWidths[0]));
+        memcpy(mKeyHeights, keyHeights, KEY_COUNT * sizeof(mKeyHeights[0]));
+        memcpy(mKeyCharCodes, keyCharCodes, KEY_COUNT * sizeof(mKeyCharCodes[0]));
+    }
+
+    initializeCodeToGroup();
+    initializeCodeToKeyIndex();
+}
+
+// Build the reversed look up table from the char code to the index in its group.
+// see TOUCH_POSITION_CORRECTION_GROUPS
+void ProximityInfo::initializeCodeToGroup() {
+    memset(mCodeToGroup, -1, (MAX_GROUPED_CHAR_CODE + 1) * sizeof(mCodeToGroup[0]));
+    for (int i = 0; i < CORRECTION_GROUP_COUNT; ++i) {
+        const char *group = TOUCH_POSITION_CORRECTION_GROUPS[i];
+        for (int j = 0; group[j]; ++j) {
+            const int code = group[j];
+            if (0 <= code && code <= MAX_GROUPED_CHAR_CODE)
+                mCodeToGroup[code] = i;
+        }
+    }
+}
+
+// Build the reversed look up table from the char code to the index in mKeyXCoordinates,
+// mKeyYCoordinates, mKeyWidths, mKeyHeights, mKeyCharCodes.
+void ProximityInfo::initializeCodeToKeyIndex() {
+    memset(mCodeToKeyIndex, -1, (MAX_GROUPED_CHAR_CODE + 1) * sizeof(mCodeToKeyIndex[0]));
+    for (int i = 0; i < KEY_COUNT; ++i) {
+        const int code = mKeyCharCodes[i];
+        if (0 <= code && code <= MAX_GROUPED_CHAR_CODE)
+            mCodeToKeyIndex[code] = i;
+    }
 }
 
 ProximityInfo::~ProximityInfo() {
@@ -162,4 +206,7 @@
     return true;
 }
 
+const int ProximityInfo::MAX_KEY_COUNT_IN_A_KEYBOARD;
+const int ProximityInfo::MAX_GROUPED_CHAR_CODE;
+
 } // namespace latinime
diff --git a/native/src/proximity_info.h b/native/src/proximity_info.h
index 75fc8fb..834997f 100644
--- a/native/src/proximity_info.h
+++ b/native/src/proximity_info.h
@@ -35,7 +35,9 @@
 
     ProximityInfo(const int maxProximityCharsSize, const int keyboardWidth,
             const int keybaordHeight, const int gridWidth, const int gridHeight,
-            const uint32_t *proximityCharsArray);
+            const uint32_t *proximityCharsArray, const int keyCount, const int32_t *keyXCoordinates,
+            const int32_t *keyYCoordinates, const int32_t *keyWidths, const int32_t *keyHeights,
+            const int32_t *keyCharCodes);
     ~ProximityInfo();
     bool hasSpaceProximity(const int x, const int y) const;
     void setInputParams(const int* inputCodes, const int inputLength);
@@ -51,7 +53,14 @@
     }
 
 private:
+    // The max number of the keys in one keyboard layout
+    static const int MAX_KEY_COUNT_IN_A_KEYBOARD = 64;
+    // The upper limit of the char code in TOUCH_POSITION_CORRECTION_GROUP
+    static const int MAX_GROUPED_CHAR_CODE = 127;
+
     int getStartIndexFromCoordinates(const int x, const int y) const;
+    void initializeCodeToGroup();
+    void initializeCodeToKeyIndex();
     const int MAX_PROXIMITY_CHARS_SIZE;
     const int KEYBOARD_WIDTH;
     const int KEYBOARD_HEIGHT;
@@ -59,10 +68,18 @@
     const int GRID_HEIGHT;
     const int CELL_WIDTH;
     const int CELL_HEIGHT;
+    const int KEY_COUNT;
     const int *mInputCodes;
     uint32_t *mProximityCharsArray;
+    int32_t mKeyXCoordinates[MAX_KEY_COUNT_IN_A_KEYBOARD];
+    int32_t mKeyYCoordinates[MAX_KEY_COUNT_IN_A_KEYBOARD];
+    int32_t mKeyWidths[MAX_KEY_COUNT_IN_A_KEYBOARD];
+    int32_t mKeyHeights[MAX_KEY_COUNT_IN_A_KEYBOARD];
+    int32_t mKeyCharCodes[MAX_KEY_COUNT_IN_A_KEYBOARD];
     int mInputLength;
     unsigned short mPrimaryInputWord[MAX_WORD_LENGTH_INTERNAL];
+    int mCodeToGroup[MAX_GROUPED_CHAR_CODE + 1];
+    int mCodeToKeyIndex[MAX_GROUPED_CHAR_CODE + 1];
 };
 
 } // namespace latinime