diff --git a/src/mo_detect.cpp b/src/mo_detect.cpp
index 1ec2d20..83b5ba2 100644
--- a/src/mo_detect.cpp
+++ b/src/mo_detect.cpp
@@ -14,22 +14,15 @@
 
 bool pixDiff(const uchar &pixA, const uchar &pixB, shared_t *share)
 {
-    auto diff = 0;
+    if (pixA > pixB) return true;
+    if (pixB > pixA) return true;
 
-    if (pixA > pixB) diff = pixA - pixB;
-    if (pixB > pixA) diff = pixB - pixA;
-
-    if (diff < share->colorThresh)
-    {
-        diff = 0;
-    }
-
-    return diff != 0;
+    return false;
 }
 
-void secDiff(const Mat &imgA, const Mat &imgB, int rows, int cols, int rowOffs, int colOffs, vector<sec_t> *results, mutex *secMutex, shared_t *share)
+void secDiff(const Mat &imgA, const Mat &imgB, int id, int rows, int cols, int rowOffs, int colOffs, vector<sec_t> *results, mutex *secMutex, shared_t *share)
 {
-    auto pnts = 0;
+    auto diff = 0;
 
     for (auto y = rowOffs; y < (rowOffs + rows); y++)
     {
@@ -38,20 +31,21 @@ void secDiff(const Mat &imgA, const Mat &imgB, int rows, int cols, int rowOffs,
             auto pixA = imgA.at<uchar>(Point(x, y));
             auto pixB = imgB.at<uchar>(Point(x, y));
 
-            if (pixDiff(pixA, pixB, share))
-            {
-                pnts += 1;
-            }
+            if (pixDiff(pixA, pixB, share)) diff += 1;
+            else                            diff -= 1;
         }
     }
 
+    if (diff < 0) diff = 0;
+
     struct sec_t res;
 
     res.x       = colOffs;
     res.y       = rowOffs;
     res.xSize   = cols;
     res.ySize   = rows;
-    res.pixDiff = pnts;
+    res.pixDiff = diff;
+    res.id      = id;
 
     lock_guard<mutex> guard(*secMutex);
 
@@ -64,12 +58,14 @@ bool imgDiff(const Mat &prev, const Mat &next, shared_t *share)
     vector<sec_t>  results;
     mutex          secMutex;
 
+    auto id = 0;
+
     for (auto x = 0; x < prev.cols; x += share->blockX)
     {
         // spawn all of the block motion detection threads.
-        for (auto y = 0; y < prev.rows; y += share->blockY)
+        for (auto y = 0; y < prev.rows; y += share->blockY, id += 1)
         {
-            threads.push_back(thread(secDiff, prev, next, share->blockY, share->blockX, y, x, &results, &secMutex, share));
+            threads.push_back(thread(secDiff, prev, next, id, share->blockY, share->blockX, y, x, &results, &secMutex, share));
         }
     }
 
@@ -89,12 +85,9 @@ bool imgDiff(const Mat &prev, const Mat &next, shared_t *share)
         auto x    = results[i].x;
         auto y    = results[i].y;
         auto diff = results[i].pixDiff;
+        auto id   = results[i].id;
 
-        share->stat += string("block_thread:")
-                    + " x="       + to_string(x)
-                    + " y="       + to_string(y)
-                    + " pixdiff=" + to_string(diff)
-                    + "\n";
+        share->stat += string("block_thread:") + " id=" + to_string(id) + " diff=" + to_string(diff) + "\n";
 
         if ((results[i].pixDiff >= share->blockThresh) && (results[i].pixDiff > maxPixDiff))
         {
@@ -103,19 +96,7 @@ bool imgDiff(const Mat &prev, const Mat &next, shared_t *share)
         }
     }
 
-    if (maxPixDiff >= share->blockThresh)
-    {
-        // run optical flow calcuations on the block with the highest
-        // pixDiff.
-        auto res   = results[blockPick];
-        auto block = Rect(res.x, res.y, res.xSize, res.ySize);
-
-        return objectFlowInImage(prev, next, block, share);
-    }
-    else
-    {
-        return false;
-    }
+    return maxPixDiff >= share->blockThresh;
 }
 
 bool moDetect(const string &buffFile, shared_t *share)
@@ -129,8 +110,6 @@ bool moDetect(const string &buffFile, shared_t *share)
         Mat prev;
         Mat next;
 
-        share->stat += "motion_detection-- clip_file - " + buffFile + "\n";
-
         while (capPair(prev, next, capture, share))
         {
             if (imgDiff(toGray(prev), toGray(next), share))
diff --git a/src/mo_detect.h b/src/mo_detect.h
index 575ef53..fd35186 100644
--- a/src/mo_detect.h
+++ b/src/mo_detect.h
@@ -14,10 +14,10 @@
 //    GNU General Public License for more details.
 
 #include "common.h"
-#include "obj_detect.h"
 
 struct sec_t
 {
+    int id;
     int x;
     int y;
     int xSize;
@@ -25,7 +25,7 @@ struct sec_t
     int pixDiff;
 };
 
-void secDiff(const Mat &imgA, const Mat &imgB, int rows, int cols, int rowOffs, int colOffs, vector<sec_t> *results, mutex *secMutex, shared_t *share);
+void secDiff(const Mat &imgA, const Mat &imgB, int id, int rows, int cols, int rowOffs, int colOffs, vector<sec_t> *results, mutex *secMutex, shared_t *share);
 bool pixDiff(const uchar &pixA, const uchar &pixB, shared_t *share);
 bool imgDiff(const Mat &prev, const Mat &next, shared_t *share);
 bool moDetect(const string &buffFile, shared_t *share);