From aeb2618a345dd7a180faa505d74a1b735da07202 Mon Sep 17 00:00:00 2001
From: Pierre Colle <piercus@gmail.com>
Date: Sat, 12 Nov 2016 17:34:06 +0100
Subject: [PATCH] revert dct example

---
 examples/mat-dct.js | 116 ++++----------------------------------------
 1 file changed, 9 insertions(+), 107 deletions(-)

diff --git a/examples/mat-dct.js b/examples/mat-dct.js
index ec9d193..b3fa89f 100644
--- a/examples/mat-dct.js
+++ b/examples/mat-dct.js
@@ -1,120 +1,22 @@
 var cv = require('../lib/opencv');
 
-var createGaussianKernel = function(sigma){
-  var cst = 1;
-  var denom = (2*sigma*sigma);
-  var factor = 100;
-  return {
-    get : function(i,j){
-      //console.log(cst, denom, ((i/10)*(i/10)+(j/10)*(j/10)), denom, Math.exp((i*i+j*j)/denom))
-      return cst*Math.exp(-1*(i*i+j*j)/denom);
-    }
-  }
-};
-
-var convolve = function(m1, m2){
-  var nCols = m1.width();
-  var nRows = m1.height();
-
-  var max = 0;
-
-  var res = new cv.Matrix(nRows, nCols, cv.Constants.CV_32FC1);
-
-  for(var i = 0; i < nCols; i++){
-    for(var j = 0; j < nRows; j++){
-      sum = 0;
-
-      for(var i2 = i-nCols+1; i2 <= i; i2++){
-        for(var j2 = j-nRows+1; j2 <= j; j2++){
-          sum += m1.get(i-i2,j-j2)*m2.get(i2,j2)
-          if(isNaN(sum)){
-            console.log(m1.get(i-i2,j-j2),m2.get(i2,j2), i-i2,i2,j-j2,j2)
-            throw("sum is NaN")
-          }
-        }
-      }
-      //console.log(sum)
-
-      if(sum > max){
-        max = sum
-      }
-
-      res.set(i,j, sum);
-    }
-  }
-  //console.log(max);
-
-  for(var i = 0; i < nCols; i++){
-    for(var j = 0; j < nRows; j++){
-      res.set(i,j, res.get(i,j)/max);
-    }
-  }
-  return res;
-
-};
-
-var getSalient = function(channel){
-  var floatInputMatrix = new cv.Matrix();
-  channel.convertTo(floatInputMatrix, cv.Constants.CV_32F);
-  var floatAfterDct = floatInputMatrix.dct();
-
-  var nCols = channel.width();
-  var nRows = channel.height();
-
-  var signs = new cv.Matrix(nRows, nCols, cv.Constants.CV_32FC1);
-  var arr = [];
-  for(var i = 0; i < nCols; i++){
-    var row = [];
-    for(var j = 0; j < nRows; j++){
-      if(floatAfterDct.get(i,j) < 0){
-        signs.set(i, j,  -1);
-      } else if(floatAfterDct.get(i,j) == 0){
-        signs.set(i, j, 0);
-      } else {
-        signs.set(i, j, 1);
-      }
-    }
-    arr.push(row)
-  }
-  // for inverse dct, set argument to "true"
-  var afterDoubleDct = signs.idct();
-  //console.log(afterDoubleDct.getData())
-  var squaredFloat = new cv.Matrix(nRows, nCols, cv.Constants.CV_32FC1);
-
-  for(var i = 0; i < nCols; i++){
-    for(var j = 0; j < nRows; j++){
-      var v = afterDoubleDct.get(i,j)
-      squaredFloat.set(i,j, v * v)
-    }
-  }
-
-  var sigma = 0.3;
-
-  var res = convolve(squaredFloat, createGaussianKernel(sigma))
-  var outChannel = new cv.Matrix(nRows, nCols, cv.Constants.CV_8U);
-
-  res.convertTo(outChannel, cv.Constants.CV_8U, 255);
-
-  return outChannel;
-};
-
 cv.readImage("./files/mona.png", function(err, orig) {
   if (err) throw err;
 
-  orig.resize(64, 64);
+  var chan1 = orig.split()[0];
 
-  var channels = orig.split();
-  var outChannels = [];
+  var floatInputMatrix = new cv.Matrix();
+  chan1.convertTo(floatInputMatrix, cv.Constants.CV_32F)
 
-  for(var chanIdx = 0; chanIdx < channels.length; chanIdx++){
-    outChannels.push(getSalient(channels[chanIdx]));
-  }
+  var foatAfterDct = floatInputMatrix.dct();
 
-  var outImg = new cv.Matrix()
+  // for inverse dct, set argument to "true"
+  var afterDoubleDct = foatAfterDct.dct(true);
 
-  outImg.merge(outChannels)
+  var intOutImage = new cv.Matrix();
 
-  outImg.save("./tmp/dct.png");
+  afterDoubleDct.convertTo(intOutImage, cv.Constants.CV_8U);
+  intOutImage.save("./tmp/dct.png");
   console.log('Image saved to ./tmp/dct.png');
 
 });