diff --git a/modules/calib3d/src/stereobm.cpp b/modules/calib3d/src/stereobm.cpp
index e7094c642c..2c8e23f4a9 100644
--- a/modules/calib3d/src/stereobm.cpp
+++ b/modules/calib3d/src/stereobm.cpp
@@ -344,7 +344,7 @@ static void findStereoCorrespondenceBM_SSE2( const Mat& left, const Mat& right,
     {
         hsad = hsad0 - dy0*ndisp; cbuf = cbuf0 + (x + wsz2 + 1)*cstep - dy0*ndisp;
         lptr = lptr0 + MIN(MAX(x, -lofs), width-lofs-1) - dy0*sstep;
-        rptr = rptr0 + MIN(MAX(x, -rofs), width-rofs-1) - dy0*sstep;
+        rptr = rptr0 + MIN(MAX(x, -rofs), width-rofs-ndisp) - dy0*sstep;
 
         for( y = -dy0; y < height + dy1; y++, hsad += ndisp, cbuf += ndisp, lptr += sstep, rptr += sstep )
         {
@@ -385,7 +385,7 @@ static void findStereoCorrespondenceBM_SSE2( const Mat& left, const Mat& right,
         hsad = hsad0 - dy0*ndisp;
         lptr_sub = lptr0 + MIN(MAX(x0, -lofs), width-1-lofs) - dy0*sstep;
         lptr = lptr0 + MIN(MAX(x1, -lofs), width-1-lofs) - dy0*sstep;
-        rptr = rptr0 + MIN(MAX(x1, -rofs), width-1-rofs) - dy0*sstep;
+        rptr = rptr0 + MIN(MAX(x1, -rofs), width-ndisp-rofs) - dy0*sstep;
 
         for( y = -dy0; y < height + dy1; y++, cbuf += ndisp, cbuf_sub += ndisp,
              hsad += ndisp, lptr += sstep, lptr_sub += sstep, rptr += sstep )
@@ -610,7 +610,7 @@ findStereoCorrespondenceBM( const Mat& left, const Mat& right,
     {
         hsad = hsad0 - dy0*ndisp; cbuf = cbuf0 + (x + wsz2 + 1)*cstep - dy0*ndisp;
         lptr = lptr0 + std::min(std::max(x, -lofs), width-lofs-1) - dy0*sstep;
-        rptr = rptr0 + std::min(std::max(x, -rofs), width-rofs-1) - dy0*sstep;
+        rptr = rptr0 + std::min(std::max(x, -rofs), width-rofs-ndisp) - dy0*sstep;
 
         for( y = -dy0; y < height + dy1; y++, hsad += ndisp, cbuf += ndisp, lptr += sstep, rptr += sstep )
         {
@@ -661,7 +661,7 @@ findStereoCorrespondenceBM( const Mat& left, const Mat& right,
         hsad = hsad0 - dy0*ndisp;
         lptr_sub = lptr0 + MIN(MAX(x0, -lofs), width-1-lofs) - dy0*sstep;
         lptr = lptr0 + MIN(MAX(x1, -lofs), width-1-lofs) - dy0*sstep;
-        rptr = rptr0 + MIN(MAX(x1, -rofs), width-1-rofs) - dy0*sstep;
+        rptr = rptr0 + MIN(MAX(x1, -rofs), width-ndisp-rofs) - dy0*sstep;
 
         for( y = -dy0; y < height + dy1; y++, cbuf += ndisp, cbuf_sub += ndisp,
              hsad += ndisp, lptr += sstep, lptr_sub += sstep, rptr += sstep )
diff --git a/modules/calib3d/src/stereosgbm.cpp b/modules/calib3d/src/stereosgbm.cpp
index 01661813a2..4c8adb9f9d 100644
--- a/modules/calib3d/src/stereosgbm.cpp
+++ b/modules/calib3d/src/stereosgbm.cpp
@@ -99,7 +99,7 @@ StereoSGBM::~StereoSGBM()
 }
 
 /*
- For each pixel row1[x], max(-maxD, 0) <= minX <= x < maxX <= width - max(0, -minD),
+ For each pixel row1[x], max(-maxD, 0) <= minX <= x < maxX <= width - max(0, minD),
  and for each disparity minD<=d<maxD the function
  computes the cost (cost[(x-minX)*(maxD - minD) + (d - minD)]), depending on the difference between
  row1[x] and row2[x-d]. The subpixel algorithm from
@@ -114,8 +114,8 @@ static void calcPixelCostBT( const Mat& img1, const Mat& img2, int y,
                             int tabOfs, int )
 {
     int x, c, width = img1.cols, cn = img1.channels();
-    int minX1 = max(-maxD, 0), maxX1 = width + min(minD, 0);
-    int minX2 = max(minX1 - maxD, 0), maxX2 = min(maxX1 - minD, width);
+    int minX1 = max(-maxD, 0), maxX1 = width + min(-minD, 0);
+    int minX2 = max(minX1 + minD, 0), maxX2 = min(maxX1 + maxD, width);
     int D = maxD - minD, width1 = maxX1 - minX1, width2 = maxX2 - minX2;
     const PixType *row1 = img1.ptr<PixType>(y), *row2 = img2.ptr<PixType>(y);
     PixType *prow1 = buffer + width2*2, *prow2 = prow1 + width*cn*2;
@@ -200,6 +200,19 @@ static void calcPixelCostBT( const Mat& img1, const Mat& img2, int y,
             int u0 = min(ul, ur); u0 = min(u0, u);
             int u1 = max(ul, ur); u1 = max(u1, u);
 
+            int minDlocal = max(minD, x-width+1);
+            int maxDlocal = min(maxD, x);
+            int d;
+            for( d = minD; d < minDlocal; d++ )
+            {
+                int v = prow2[0];
+                int v0 = buffer[0];
+                int v1 = buffer[width2];
+                int c0 = max(0, u - v1); c0 = max(c0, v0 - u);
+                int c1 = max(0, v - u1); c1 = max(c1, u0 - v);
+
+                cost[x*D + d] = (CostType)(cost[x*D+d] + (min(c0, c1) >> diff_scale));
+            }
         #if CV_SSE2
             if( useSIMD )
             {
@@ -207,7 +220,7 @@ static void calcPixelCostBT( const Mat& img1, const Mat& img2, int y,
                 __m128i _u1 = _mm_set1_epi8((char)u1), z = _mm_setzero_si128();
                 __m128i ds = _mm_cvtsi32_si128(diff_scale);
 
-                for( int d = minD; d < maxD; d += 16 )
+                for( ; d < maxDlocal - 15; d += 16 )
                 {
                     __m128i _v = _mm_loadu_si128((const __m128i*)(prow2 + width-x-1 + d));
                     __m128i _v0 = _mm_loadu_si128((const __m128i*)(buffer + width-x-1 + d));
@@ -223,19 +236,26 @@ static void calcPixelCostBT( const Mat& img1, const Mat& img2, int y,
                     _mm_store_si128((__m128i*)(cost + x*D + d + 8), _mm_adds_epi16(c1, _mm_srl_epi16(_mm_unpackhi_epi8(diff,z), ds)));
                 }
             }
-            else
         #endif
+            for( ; d < maxDlocal; d++ )
             {
-                for( int d = minD; d < maxD; d++ )
-                {
-                    int v = prow2[width-x-1 + d];
-                    int v0 = buffer[width-x-1 + d];
-                    int v1 = buffer[width-x-1 + d + width2];
-                    int c0 = max(0, u - v1); c0 = max(c0, v0 - u);
-                    int c1 = max(0, v - u1); c1 = max(c1, u0 - v);
+                int v = prow2[width-x-1 + d];
+                int v0 = buffer[width-x-1 + d];
+                int v1 = buffer[width-x-1 + d + width2];
+                int c0 = max(0, u - v1); c0 = max(c0, v0 - u);
+                int c1 = max(0, v - u1); c1 = max(c1, u0 - v);
 
-                    cost[x*D + d] = (CostType)(cost[x*D+d] + (min(c0, c1) >> diff_scale));
-                }
+                cost[x*D + d] = (CostType)(cost[x*D+d] + (min(c0, c1) >> diff_scale));
+            }
+            for( ; d < maxD; d++ )
+            {
+                int v = prow2[width-1];
+                int v0 = buffer[width-1];
+                int v1 = buffer[width-1 + width2];
+                int c0 = max(0, u - v1); c0 = max(c0, v0 - u);
+                int c1 = max(0, v - u1); c1 = max(c1, u0 - v);
+
+                cost[x*D + d] = (CostType)(cost[x*D+d] + (min(c0, c1) >> diff_scale));
             }
         }
     }
@@ -329,7 +349,7 @@ static void computeDisparitySGBM( const Mat& img1, const Mat& img2,
     int disp12MaxDiff = params.disp12MaxDiff > 0 ? params.disp12MaxDiff : 1;
     int P1 = params.P1 > 0 ? params.P1 : 2, P2 = max(params.P2 > 0 ? params.P2 : 5, P1+1);
     int k, width = disp1.cols, height = disp1.rows;
-    int minX1 = max(-maxD, 0), maxX1 = width + min(minD, 0);
+    int minX1 = max(-maxD, 0), maxX1 = width + min(-minD, 0);
     int D = maxD - minD, width1 = maxX1 - minX1;
     int INVALID_DISP = minD - 1, INVALID_DISP_SCALED = INVALID_DISP*DISP_SCALE;
     int SW2 = SADWindowSize.width/2, SH2 = SADWindowSize.height/2;
@@ -377,6 +397,7 @@ static void computeDisparitySGBM( const Mat& img1, const Mat& img2,
 
     // summary cost over different (nDirs) directions
     CostType* Cbuf = (CostType*)alignPtr(buffer.data, ALIGN);
+    memset(Cbuf, 0, CSBufSize*sizeof(CostType));
     CostType* Sbuf = Cbuf + CSBufSize;
     CostType* hsumBuf = Sbuf + CSBufSize;
     CostType* pixDiff = hsumBuf + costBufSize*hsumBufNRows;