diff --git a/api/reduce.cpp b/api/reduce.cpp
index fbe3d427e0..4bca02847b 100644
--- a/api/reduce.cpp
+++ b/api/reduce.cpp
@@ -11,6 +11,7 @@ REDUCED_ARRAY::REDUCED_ARRAY() {
     rdata = 0;
     ftemp = 0;
     itemp = 0;
+	reduce_method = REDUCE_METHOD_AVG;
 }
 
 REDUCED_ARRAY::~REDUCED_ARRAY() {
@@ -54,6 +55,7 @@ void REDUCED_ARRAY::init(int sx, int sy) {
     last_ry = 0;
     last_ry_count = 0;
     rdata_max = 0;
+	rdata_min = (float)1e20;
 }
 
 bool REDUCED_ARRAY::full() {
@@ -86,12 +88,27 @@ void REDUCED_ARRAY::reduce_source_row(float* in, float* out) {
     memset(itemp, 0, rdimx*sizeof(int));
     for (i=0; i<sdimx; i++) {
         ri = (i*rdimx)/sdimx;
-        out[ri] += in[i];
-        itemp[ri]++;
-    }
-    for (i=0; i<rdimx; i++) {
-        if (itemp[i] > 1) out[i] /= itemp[i];
+		switch (reduce_method) {
+		case REDUCE_METHOD_AVG:
+            out[ri] += in[i];
+            itemp[ri]++;
+            break;
+		case REDUCE_METHOD_SUM:
+            out[ri] += in[i];
+            break;
+		case REDUCE_METHOD_MIN:
+            out[ri] = min(out[ri],in[i]);
+            break;
+		case REDUCE_METHOD_MAX:
+            out[ri] = max(out[ri],in[i]);
+            break;
+		}
     }
+	if (reduce_method==REDUCE_METHOD_AVG) {
+        for (i=0; i<rdimx; i++) {
+            if (itemp[i] > 1) out[i] /= itemp[i];
+        }
+	}
 }
 
 void REDUCED_ARRAY::update_max(int row) {
@@ -100,6 +117,7 @@ void REDUCED_ARRAY::update_max(int row) {
 
     for (i=0; i<rdimx; i++) {
         if (p[i] > rdata_max) rdata_max = p[i];
+        if (p[i] < rdata_min) rdata_min = p[i];
     }
 }
 
@@ -183,10 +201,10 @@ void REDUCED_ARRAY::draw_row_quad(int row) {
     for (i=0; i<rdimx-1; i++) {
         x0 = draw_pos[0] + (draw_size[0]*i)/rdimx;
         x1 = x0 + draw_deltax;
-        float h00 = row0[i]/rdata_max;
-        float h01 = row0[i+1]/rdata_max;
-        float h10 = row1[i]/rdata_max;
-        float h11 = row1[i+1]/rdata_max;
+        float h00 = (row0[i]-rdata_min)/(rdata_max-rdata_min);
+        float h01 = (row0[i+1]-rdata_min)/(rdata_max-rdata_min);
+        float h10 = (row1[i]-rdata_min)/(rdata_max-rdata_min);
+        float h11 = (row1[i+1]-rdata_min)/(rdata_max-rdata_min);
 
         y00 = draw_pos[1] + draw_size[1]*h00;
         y01 = draw_pos[1] + draw_size[1]*h01;
@@ -217,10 +235,10 @@ void REDUCED_ARRAY::draw_row_quad(int row) {
         x0 = draw_pos[0] + (draw_size[0]*i)/rdimx;
         x1 = x0 + draw_deltax;
         float eps=.03f;
-        y00 = draw_pos[1] + draw_size[1]*row0[i]/rdata_max+eps;
-        y01 = draw_pos[1] + draw_size[1]*row0[i+1]/rdata_max+eps;
-        y10 = draw_pos[1] + draw_size[1]*row1[i]/rdata_max+eps;
-        y11 = draw_pos[1] + draw_size[1]*row1[i+1]/rdata_max+eps;
+        y00 = draw_pos[1] + draw_size[1]*(row0[i]-rdata_min)/rdata_max+eps;
+        y01 = draw_pos[1] + draw_size[1]*(row0[i+1]-rdata_min)/rdata_max+eps;
+        y10 = draw_pos[1] + draw_size[1]*(row1[i]-rdata_min)/rdata_max+eps;
+        y11 = draw_pos[1] + draw_size[1]*(row1[i+1]-rdata_min)/rdata_max+eps;
         glVertex3f(x0, y00, z0);
         glVertex3f(x1, y01, z0);
         glVertex3f(x1, y01, z0);
@@ -240,7 +258,7 @@ void REDUCED_ARRAY::draw_row_rect_x(int row) {
     for (i=0; i<rdimx; i++) {
         x0 = draw_pos[0] + (draw_size[0]*i)/rdimx;
         x1 = x0 + draw_deltax*.8f;
-        float h = row0[i]/rdata_max;
+        float h = (row0[i]-rdata_min)/(rdata_max-rdata_min);
 
         y0 = draw_pos[1];
         y1 = draw_pos[1] + draw_size[1]*h;
@@ -267,7 +285,7 @@ void REDUCED_ARRAY::draw_row_rect_x(int row) {
     for (i=0; i<rdimx; i++) {
         x0 = draw_pos[0] + (draw_size[0]*i)/rdimx;
         x1 = x0 + draw_deltax*.8f;
-        float h = row0[i]/rdata_max;
+        float h = (row0[i]-rdata_min)/(rdata_max-rdata_min);
 
         y1 = draw_pos[1] + draw_size[1]*h;
 
@@ -287,7 +305,7 @@ void REDUCED_ARRAY::draw_row_rect_y(int row) {
     glBegin(GL_QUADS);
     for (i=0; i<rdimx-1; i++) {
         x0 = draw_pos[0] + (draw_size[0]*i)/rdimx;
-        float h = row0[i]/rdata_max;
+        float h = (row0[i]-rdata_min)/(rdata_max-rdata_min);
 
         y0 = draw_pos[1];
         y1 = draw_pos[1] + draw_size[1]*h;
@@ -313,7 +331,7 @@ void REDUCED_ARRAY::draw_row_rect_y(int row) {
     glColor3f(0., 0., 0.);
     for (i=0; i<rdimx-1; i++) {
         x0 = draw_pos[0] + (draw_size[0]*i)/rdimx;
-        float h = row0[i]/rdata_max;
+        float h = (row0[i]-rdata_min)/(rdata_max-rdata_min);
 
         y1 = draw_pos[1] + draw_size[1]*h;
 
diff --git a/api/reduce.h b/api/reduce.h
index 772e0cb7f4..99e2b5a1cb 100644
--- a/api/reduce.h
+++ b/api/reduce.h
@@ -19,6 +19,12 @@
 //     If reduced in one dimension, draw vertical rectangles.
 //     Otherwise draw quadrilaterals.
 
+
+#define REDUCE_METHOD_AVG	0		// Take the average of reduced elements
+#define REDUCE_METHOD_SUM	1		// Take the sum of reduced elements
+#define REDUCE_METHOD_MAX	2		// Take the maximum of reduced elements
+#define REDUCE_METHOD_MIN	3		// Take the minimum of reduced elements
+
 class REDUCED_ARRAY {
 public:
     int sdimx, sdimy;           // size of the source array
@@ -28,6 +34,7 @@ public:
     int scury;                  // next row of source array
     float* rdata;
     float rdata_max;            // estimated or actual maximum
+    float rdata_min;            // estimated or actual minimum
     float* ftemp;
     int* itemp;
         // the following 2 are relevant only if sdimy > rdimy
@@ -39,6 +46,7 @@ public:
     float draw_size[3];
     float draw_deltax;
     float draw_deltaz;
+	int reduce_method;			// Which method to use for data row reduction
     double hue0;
     double dhue;