adding emd

examples/emd.js

@@ -0,0 +1,72 @@
+var cv = require('../lib/opencv');
+
+// (B)lue, (G)reen, (R)ed
+var histSize = 256;
+
+cv.readImage('./files/car1.jpg', function(err, im1) {
+  if (err) throw err;
+  if (im.width() < 1 || im.height() < 1) throw new Error('Image has no size');
+  cv.readImage('./files/car2.jpg', function(err, im2) {
+
+    var bgrPlanes = im.split();
+
+    var size = [4, 4, 4],
+        channels = [0, 1, 2],
+        range = [[0, 256], [0, 256], [0, 256]],
+        uniform = true,
+        accumulate = true,
+        histFile = 'files/chart2.png';
+
+
+    /// Compute 64 (=4^3) histograms:
+
+    var firstImageHist64 = cv.histogram.calcHist(im1, channels, size, range, uniform, accumulate);
+    var secondImageHist64 = cv.histogram.calcHist(im2, channels, size, range, uniform, accumulate);
+
+    var sig1 = flatten(firstImageHist64);
+    var sig2 = flatten(secondImageHist64);
+
+    var step = 256/4;
+    var halfStep = Math.round(step/2)
+
+    var middles = flatten(firstImageHist64.map(function(bHist, bIndex){
+      return blueValue.map(function(bgHist, gIndex){
+        return greenValue.map(function(bgrHist, rIndex){
+          return [
+            bIndex*step + halfStep,
+            gIndex*step + halfStep,
+            rIndex*step + halfStep
+          ];/*{
+            b : bIndex*step + halfStep,
+            g : gIndex*step + halfStep,
+            r : rIndex*step + halfStep
+          }*/
+        })
+      })
+    }));
+
+    var mat = new opencv.Matrix(64,1,cv.Constants.CV_8UC3);
+    var buf = Buffer(64*1*3);
+    buf.fill(0);
+    for(var i=0;i<64*1*3;i++){
+      buf[i] = middles[i];
+    }
+    mat.put(buf);
+    mat.cvtColor("CV_BGR2Luv");
+
+    var luvValues = mat.toArray()[0];
+
+    var distance = function(luv1, luv2){
+      return Math.sqrt((luv1[0]-luv2[0])*(luv1[0]-luv2[0]) + (luv1[1]-luv2[1])*(luv1[1]-luv2[1]) + (luv1[2]-luv2[2])*(luv1[2]-luv2[2]));
+    };
+
+    var costs = luvValues.map(function(luvMiddle1){
+      return middles.map(function(luvMiddle2){
+        return distance(luvMiddle1, luvMiddle2);
+      })
+    })
+
+    emd(sig1, sig2, cv.Constants.CV_DIST_USER, cost);
+
+  });
+});