diff --git a/sdk/plugins/algorithms.cpp b/sdk/plugins/algorithms.cpp
index 232201d..28efccc 100644
--- a/sdk/plugins/algorithms.cpp
+++ b/sdk/plugins/algorithms.cpp
@@ -50,6 +50,7 @@ class AlgorithmsInitializer : public Initializer
         Globals->abbreviations.insert("SmallSIFT", "Open+LimitSize(512)+KeyPointDetector(SIFT)+KeyPointDescriptor(SIFT):KeyPointMatcher(BruteForce)");
         Globals->abbreviations.insert("SmallSURF", "Open+LimitSize(512)+KeyPointDetector(SURF)+KeyPointDescriptor(SURF):KeyPointMatcher(BruteForce)");
         Globals->abbreviations.insert("ColorHist", "Open+LimitSize(512)!EnsureChannels(3)+SplitChannels+Hist(256,0,8)+Cat+Normalize(L1):L2");
+        Globals->abbreviations.insert("IHH", "Open+SplitChannels/(Cvt(Gray)+Gradient+Bin(0,6.283,8,true))+Integral+Merge+IntegralSampler");
 
         // Hash
         Globals->abbreviations.insert("FileName", "Name+Identity:Identical");
diff --git a/sdk/plugins/hist.cpp b/sdk/plugins/hist.cpp
index 0a87290..1a94431 100644
--- a/sdk/plugins/hist.cpp
+++ b/sdk/plugins/hist.cpp
@@ -164,91 +164,6 @@ class IntegralHistTransform : public UntrainableTransform
 
 BR_REGISTER(Transform, IntegralHistTransform)
 
-/*!
- * \ingroup transforms
- * \brief Detects regions of low variance
- * \author Josh Klontz \cite jklontz
- */
-class VarianceChangeDetectorTransform : public UntrainableTransform
-{
-    Q_OBJECT
-    Q_PROPERTY(int bins READ get_bins WRITE set_bins RESET reset_bins STORED false)
-    Q_PROPERTY(int radius READ get_radius WRITE set_radius RESET reset_radius STORED false)
-    BR_PROPERTY(int, bins, 256)
-    BR_PROPERTY(int, radius, 16)
-
-    float stddev(const Mat &integral, int i, int j, int scale, int *buffer) const
-    {
-        const float count = scale*scale*radius*radius;
-
-        float mean = 0;
-        for (int k=0; k<bins; k++) {
-            buffer[k] = integral.at<qint32>(i+scale,(j+scale)*bins+k)
-                      - integral.at<qint32>(i+scale, j       *bins+k)
-                      - integral.at<qint32>(i      ,(j+scale)*bins+k)
-                      + integral.at<qint32>(i      , j       *bins+k);
-            mean += k*buffer[k];
-        }
-        mean /= count;
-
-        float variance = 0;
-        for (int k=0; k<bins; k++)
-            variance += buffer[k] * (k-mean) * (k-mean);
-
-        return sqrt(variance/count);
-    }
-
-    void project(const Template &src, Template &dst) const
-    {
-        const Mat &m = src.m();
-        if (m.type() != CV_32SC1) qFatal("VarianceChangeDetector requires CV_32SC1 images from IntegralHist");
-
-        int *buffer = new int[bins];
-
-        float bestRatio = -std::numeric_limits<float>::max();
-        QRectF bestRect;
-
-        const int rows = m.rows;
-        const int cols = m.cols/bins;
-        const int maxSize = min(m.rows, m.cols/bins);
-        int scale = 2;
-        while (scale < maxSize) {
-            const int step = std::max(1, scale/6);
-            for (int i=0; i+scale < rows; i+=step) {
-                for (int j=0; j+scale < cols; j+=step) {
-                    float internalStdDev = stddev(m, i, j, scale, buffer);
-                    float externalStdDev = std::numeric_limits<float>::max();
-                    externalStdDev = std::min(externalStdDev, ((i-2*scale >= 0)   && (j-2*scale >= 0))   ? stddev(m, i-2*scale, j-2*scale, scale, buffer) : 0);
-                    externalStdDev = std::min(externalStdDev,  (i-2*scale >= 0)                          ? stddev(m, i-2*scale, j        , scale, buffer) : 0);
-                    externalStdDev = std::min(externalStdDev, ((i-2*scale >= 0)   && (j+3*scale < cols)) ? stddev(m, i-2*scale, j+2*scale, scale, buffer) : 0);
-                    externalStdDev = std::min(externalStdDev,                        (j+3*scale < cols)  ? stddev(m, i        , j+2*scale, scale, buffer) : 0);
-                    externalStdDev = std::min(externalStdDev, ((i+3*scale < rows) && (j+3*scale < cols)) ? stddev(m, i+2*scale, j+2*scale, scale, buffer) : 0);
-                    externalStdDev = std::min(externalStdDev,  (i+3*scale < rows)                        ? stddev(m, i+2*scale, j        , scale, buffer) : 0);
-                    externalStdDev = std::min(externalStdDev, ((i+3*scale < rows) && (j-2*scale >= 0))   ? stddev(m, i+2*scale, j-2*scale, scale, buffer) : 0);
-                    externalStdDev = std::min(externalStdDev,                        (j-2*scale >= 0)    ? stddev(m, i        , j-2*scale, scale, buffer) : 0);
-
-                    float ratio;
-                    if      (externalStdDev == 0) ratio = 0;
-                    else if (internalStdDev == 0) ratio = std::numeric_limits<float>::max() * (float(scale)/float(maxSize));
-                    else                          ratio = scale*scale * pow(externalStdDev,2) / pow(internalStdDev, 2);
-
-                    if (ratio > bestRatio) {
-                        bestRatio = ratio;
-                        bestRect = QRect(j*radius, i*radius, scale*radius, scale*radius);
-                    }
-                }
-            }
-            scale = std::max(scale+1, int(scale*1.25));
-        }
-
-        delete[] buffer;
-        dst.file.appendRect(bestRect);
-        dst.file.setLabel(bestRatio);
-    }
-};
-
-BR_REGISTER(Transform, VarianceChangeDetectorTransform)
-
 } // namespace br
 
 #include "hist.moc"
diff --git a/sdk/plugins/integral.cpp b/sdk/plugins/integral.cpp
index 152cb41..f19fdc0 100644
--- a/sdk/plugins/integral.cpp
+++ b/sdk/plugins/integral.cpp
@@ -1,6 +1,9 @@
 #include <opencv2/imgproc/imgproc.hpp>
+#include <Eigen/Core>
 #include <openbr_plugin.h>
 
+using namespace cv;
+
 namespace br
 {
 
@@ -15,7 +18,7 @@ class IntegralTransform : public UntrainableTransform
 
     void project(const Template &src, Template &dst) const
     {
-        cv::integral(src, dst);
+        integral(src, dst);
     }
 };
 
@@ -23,6 +26,71 @@ BR_REGISTER(Transform, IntegralTransform)
 
 /*!
  * \ingroup transforms
+ * \brief Sliding window object recognition from a multi-channel intergral image.
+ * \author Josh Klontz \cite jklontz
+ */
+class IntegralSampler : public UntrainableTransform
+{
+    Q_OBJECT
+    Q_PROPERTY(int scales READ get_scales WRITE set_scales RESET reset_scales STORED false)
+    Q_PROPERTY(float scaleFactor READ get_scaleFactor WRITE set_scaleFactor RESET reset_scaleFactor STORED false)
+    Q_PROPERTY(float stepFactor READ get_stepFactor WRITE set_stepFactor RESET reset_stepFactor STORED false)
+    Q_PROPERTY(int minSize READ get_minSize WRITE set_minSize RESET reset_minSize STORED false)
+    BR_PROPERTY(int, scales, 1)
+    BR_PROPERTY(float, scaleFactor, 1.25)
+    BR_PROPERTY(float, stepFactor, 0.25)
+    BR_PROPERTY(int, minSize, 8)
+
+    void project(const Template &src, Template &dst) const
+    {
+        typedef Eigen::Map< const Eigen::Matrix<qint32,Eigen::Dynamic,1> > InputDescriptor;
+        typedef Eigen::Map< Eigen::Matrix<qint32,Eigen::Dynamic,1> > OutputDescriptor;
+        const Mat &m = src.m();
+        if (m.depth() != CV_32S) qFatal("Expected CV_32S matrix depth.");
+        const int channels = m.channels();
+        const int rowStep = channels * m.cols;
+
+        int descriptors = 0;
+        int currentSize = min(m.rows, m.cols)-1;
+        for (int scale=0; scale<scales; scale++) {
+            descriptors += ceil((m.rows-currentSize)*stepFactor/currentSize) *
+                    ceil((m.cols-currentSize)*stepFactor/currentSize);
+            currentSize /= scaleFactor;
+            if (currentSize < minSize)
+                break;
+        }
+        Mat n(descriptors, channels, CV_32SC1);
+
+        const qint32 *dataIn = (qint32*)m.data;
+        qint32 *dataOut = (qint32*)n.data;
+        currentSize = min(m.rows, m.cols)-1;
+        int index = 0;
+        for (int scale=0; scale<scales; scale++) {
+            const int currentStep = currentSize * stepFactor;
+            for (int i=currentSize; i<m.rows; i+=currentStep) {
+                for (int j=currentSize; j<m.cols; j+=currentStep) {
+                    InputDescriptor a(dataIn+((i-currentSize)*rowStep+(j-currentSize)*channels), channels, 1);
+                    InputDescriptor b(dataIn+((i-currentSize)*rowStep+ j             *channels), channels, 1);
+                    InputDescriptor c(dataIn+( i             *rowStep+(j-currentSize)*channels), channels, 1);
+                    InputDescriptor d(dataIn+( i             *rowStep+ j             *channels), channels, 1);
+                    OutputDescriptor y(dataOut+(index*channels), channels, 1);
+                    y = d-b-c+a;
+                    index++;
+                }
+            }
+            currentSize /= scaleFactor;
+            if (currentSize < minSize)
+                break;
+        }
+
+        dst.m() = n;
+    }
+};
+
+BR_REGISTER(Transform, IntegralSampler)
+
+/*!
+ * \ingroup transforms
  * \brief Computes magnitude and/or angle of image.
  * \author Josh Klontz \cite jklontz
  */
@@ -41,10 +109,10 @@ private:
     void project(const Template &src, Template &dst) const
     {
         if (src.m().type() != CV_8UC1) qFatal("Requires CV_8UC1 input.");
-        cv::Mat dx, dy, magnitude, angle;
-        cv::Sobel(src, dx, CV_32F, 1, 0);
-        cv::Sobel(src, dy, CV_32F, 0, 1);
-        cv::cartToPolar(dx, dy, magnitude, angle, true);
+        Mat dx, dy, magnitude, angle;
+        Sobel(src, dx, CV_32F, 1, 0);
+        Sobel(src, dy, CV_32F, 0, 1);
+        cartToPolar(dx, dy, magnitude, angle, true);
         if ((channel == Magnitude) || (channel == MagnitudeAndAngle))
             dst.append(magnitude);
         if ((channel == Angle) || (channel == MagnitudeAndAngle))
diff --git a/sdk/plugins/regions.cpp b/sdk/plugins/regions.cpp
index 7f13a9e..6248879 100644
--- a/sdk/plugins/regions.cpp
+++ b/sdk/plugins/regions.cpp
@@ -111,6 +111,26 @@ BR_REGISTER(Transform, CatTransform)
 
 /*!
  * \ingroup transforms
+ * \brief Wraps OpenCV merge
+ * \author Josh Klontz \cite jklontz
+ */
+class MergeTransform : public UntrainableMetaTransform
+{
+    Q_OBJECT
+
+    void project(const Template &src, Template &dst) const
+    {
+        std::vector<Mat> mv;
+        foreach (const Mat &m, src)
+            mv.push_back(m);
+        merge(mv, dst);
+    }
+};
+
+BR_REGISTER(Transform, MergeTransform)
+
+/*!
+ * \ingroup transforms
  * \brief Duplicates the template data.
  * \author Josh Klontz \cite jklontz
  */