merge compare with piercus's master branch

binding.gyp

@@ -20,7 +20,8 @@
         "src/Calib3D.cc",
         "src/ImgProc.cc",
         "src/Stereo.cc",
-        "src/LDAWrap.cc"
+        "src/LDAWrap.cc",
+        "src/Histogram.cc",        
       ],
 
       "libraries": [

examples/calc-hist.js

@@ -0,0 +1,67 @@
+var cv = require('../lib/opencv');
+
+// (B)lue, (G)reen, (R)ed
+var histSize = 256;
+
+cv.readImage('./files/car1.jpg', function(err, im) {
+  if (err) throw err;
+  if (im.width() < 1 || im.height() < 1) throw new Error('Image has no size');
+
+  var bgrPlanes = im.split();
+
+  var size = 256,
+      range = [0, 256],
+      uniform = true,
+      histFile = 'files/chart2.png';
+
+
+  /// Compute a 3 dimension histogram
+  var hist64 = cv.histogram.calcHist( im, [0, 1, 2], [4, 4, 4], [[0, 256], [0, 256], [0, 256]], uniform);
+
+  /// Compute 3 histograms
+  var bHist = cv.histogram.calcHist( im, [0], [size], [range], uniform);
+  var gHist = cv.histogram.calcHist( im, [1], [size], [range], uniform);
+  var rHist = cv.histogram.calcHist( im, [2], [size], [range], uniform);
+
+//////
+//  Uncommentand run `npm install chartjs-node` to draw the histogram !
+///
+/*
+  var ChartjsNode = require('chartjs-node');
+  var chartNode = new ChartjsNode(1200, 1200);
+  chartNode.drawChart({
+      type: 'bar',
+      data: {
+        labels: bHist.map(function(a,i){return i.toString()}),
+        datasets : [{
+          data : bHist,
+          backgroundColor : "#4183c4",
+          borderColor : "#0c4b8a",
+          label : 'Blue'
+        },{
+          data : gHist,
+          backgroundColor : "#83c441",
+          borderColor : "#0c4b8a",
+          label : 'Green'
+        },{
+          data : rHist,
+          backgroundColor : "#c44183",
+          borderColor : "#0c4b8a",
+          label : 'Red'
+        }]
+      },
+      options: {
+        title: {
+            display: true,
+            text: 'RGB Histograms'
+        }
+      }
+  }).then(function(){
+    return chartNode.writeImageToFile('image/png', histFile);
+  }).then(function(){
+    console.log("result has been written in "+histFile)
+  }).catch(function(e){
+    console.log("error",e)
+  });
+*/
+});

examples/emd.js

@@ -0,0 +1,161 @@
+var cv = require('../lib/opencv');
+
+//
+//  Example of use of EMD distance using histograms
+//  1. Build 2 histograms from images using calcHist
+//  2. Transform each histogram to a 64 x 4 (hist, b, g, r) x 1 normalized signatures in BGR space
+//  3. Compute the cost matrix (64 x 64 x 1), calculating the cost in LUV space
+//  4. Run EMD algorithm
+//
+
+/// Useful flatten function for step 2
+
+function flatten(array, accu) {
+  if(!accu){
+    accu = [];
+  }
+  array.forEach(function(a){
+    if(Array.isArray(a)) {
+      flatten(a, accu)
+    } else {
+      accu.push(a)
+    }
+  });
+  return accu
+};
+
+cv.readImage('./files/car1.jpg', function(err, im1) {
+  if (err) throw err;
+  if (im1.width() < 1 || im1.height() < 1) throw new Error('Image has no size');
+  cv.readImage('./files/car2.jpg', function(err, im2) {
+    if (err) throw err;
+    if (im2.width() < 1 || im2.height() < 1) throw new Error('Image has no size');
+
+    ///////////////////
+    //  1. Build 2 histograms from images using calcHist
+    //////////////////
+
+    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);
+    var secondImageHist64 = cv.histogram.calcHist(im2, channels, size, range, uniform);
+
+    //////////////
+    //  2. Transform each histogram to a 64 x 4 (hist, b, g, r) x 1 normalized signatures in BGR space
+    ////////////////
+
+    var step = 256/4;
+    var halfStep = Math.round(step/2);
+
+    var sum1 = 0;
+    var sum2 = 0;
+
+    firstImageHist64.map(function(bHist, bIndex){
+      return bHist.map(function(bgHist, gIndex){
+        return bgHist.map(function(bgrHist, rIndex){
+          sum1 += bgrHist;
+        })
+      })
+    })
+
+    var sig1 = flatten(firstImageHist64.map(function(bHist, bIndex){
+      return bHist.map(function(bgHist, gIndex){
+        return bgHist.map(function(bgrHist, rIndex){
+          return {
+            data :[
+              [bgrHist/sum1],
+              [bIndex*step + halfStep],
+              [gIndex*step + halfStep],
+              [rIndex*step + halfStep]
+            ]
+          }
+        })
+      })
+    })).map(function(a){
+      // trick to avoid flattening and get a 64 x 4 x 1 image as needed
+      return a.data;
+    });
+
+    secondImageHist64.map(function(bHist, bIndex){
+      return bHist.map(function(bgHist, gIndex){
+        return bgHist.map(function(bgrHist, rIndex){
+          sum2 += bgrHist;
+        })
+      })
+    })
+
+    var sig2 = flatten(secondImageHist64.map(function(bHist, bIndex){
+      return bHist.map(function(bgHist, gIndex){
+        return bgHist.map(function(bgrHist, rIndex){
+          return {
+            data : [
+              [bgrHist/sum2],
+              [bIndex*step + halfStep],
+              [gIndex*step + halfStep],
+              [rIndex*step + halfStep]
+            ]
+          };
+        })
+      })
+    })).map(function(a){
+      // trick to avoid flattening and get a 64 x 4 x 1 image as needed
+      return a.data;
+    });
+
+    /////////////
+    //  3. Compute the cost matrix (64 x 64 x 1), calculating the cost in LUV space
+    /////////////
+
+    //middles is a 1 x 64 x 3 array of the middles positions in RGB used to change to LUV
+    var middles = [flatten(firstImageHist64.map(function(bHist, bIndex){
+      return bHist.map(function(bgHist, gIndex){
+        return bgHist.map(function(bgrHist, rIndex){
+          return {
+            data : [
+              bIndex*step + halfStep,
+              gIndex*step + halfStep,
+              rIndex*step + halfStep
+            ]
+          }
+        })
+      })
+    })).map(function(a){
+      // trick to avoid flattening and get a 1 x 64 x 3 image as needed
+      return a.data;
+    })];
+
+    var mat = cv.Matrix.fromArray(middles, cv.Constants.CV_8UC3);
+    mat.cvtColor("CV_BGR2Luv");
+
+    //luvValues is a 1 x 64 x 3 array of the middles positions in LUV
+    var luvMiddles = mat.toArray();
+
+    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 = luvMiddles[0].map(function(luvMiddle1){
+      return luvMiddles[0].map(function(luvMiddle2){
+        return [distance(luvMiddle1, luvMiddle2)];
+      })
+    });
+
+    //////
+    //  4. Run EMD algorithm
+    /////
+
+    var matCosts = cv.Matrix.fromArray(costs, cv.Constants.CV_32FC1);
+    var matSig1 = cv.Matrix.fromArray(sig1, cv.Constants.CV_32FC1);
+    var matSig2 = cv.Matrix.fromArray(sig2, cv.Constants.CV_32FC1);
+
+    var dist = cv.Constants.CV_DIST_L2;
+    var emd = cv.histogram.emd(matSig1, matSig2, dist);//, matCosts);
+    console.log("EMD is ", emd)
+  });
+});

examples/mat-array-conversion.js

@@ -0,0 +1,20 @@
+var cv = require('../lib/opencv');
+
+cv.readImage("./files/mona.png", function(err, orig) {
+  if (err) throw err;
+
+  var a = orig.toArray();
+  var type = orig.type();
+  var doubleConversion = cv.Matrix.fromArray(a, type).toArray();
+
+  for(var i = 0 ; i < a.length; i++){
+    for(var j = 0 ; j < a[i].length; j++){
+      for(var k = 0 ; k < a[i][j].length; k++){
+        if(a[i][j][k] !== doubleConversion[i][j][k]){
+          throw(new Error("double conversion is not equal to original"));
+        }
+      }
+    }
+  }
+
+});

lib/opencv.js

@@ -1,7 +1,8 @@
 var Stream = require('stream').Stream
   , Buffers = require('buffers')
   , util = require('util')
-  , path = require('path');
+  , path = require('path')
+  , os = require('os');
 
 var cv = module.exports = require('./bindings');
 
@@ -33,6 +34,120 @@ Matrix.prototype.inspect = function(){
   return "[ Matrix " + size + " ]";
 }
 
+// we use the Opencv constants naming convention to extract the number of bytes (8, 16, 32, 64), and the number of channels from constants names
+var getNumberOfBytesAndChannelsPerType = function(type){
+  var regExp = /CV_([0-9]+)([A-Z]+)([0-9]+)/;
+  for(var k in cv.Constants) if(cv.Constants.hasOwnProperty(k) && k.match(regExp) && cv.Constants[k] === type){
+    var bytes, channels, dataType;
+    k.replace(regExp, function(all, b, l, c){
+      bytes = b;
+      channels = c;
+      dataType = l[0]
+    });
+
+    return {
+      bytes : parseInt(bytes),
+      channels : !isNaN(parseInt(channels)) && parseInt(channels),
+      dataType : dataType,
+      label : k
+    };
+  }
+};
+
+var getBufferMethodName = function(bytes, dataType, endianness, read){
+  var fnName;
+
+  if(read){
+    fnName = "read";
+  } else {
+    fnName = "write";
+  }
+
+  if (bytes === 32 && (dataType === "F" || dataType === "S")){
+    if(dataType === "F"){
+      fnName += "Float"+endianness;
+    } else {//dataType === "S"
+      fnName += "Int32"+endianness;
+    }
+  } else if(bytes === 8){
+    fnName += (dataType === "U" ? "U" : "")+"Int8";
+  } else if(bytes === 16){
+    fnName += (dataType === "U" ? "U" : "")+"Int16"+endianness;
+  } else {
+    throw("This matrix type (CV_"+bytes+dataType+") is not compatible with fromArray/toArray")
+  }
+  return fnName;
+};
+
+Matrix.fromArray = function(arr, type){
+  var n_bytes;
+
+  var bytesAndChannels = getNumberOfBytesAndChannelsPerType(type);
+  var bytes = bytesAndChannels.bytes;
+  var channels = bytesAndChannels.channels;
+  var dataType = bytesAndChannels.dataType;
+  var label = bytesAndChannels.label;
+
+  if(!Array.isArray(arr) ||!Array.isArray(arr[0]) || !Array.isArray(arr[0][0]) || (channels && arr[0][0].length !== channels)) {
+    throw(new Error("Input array must be a 3-level array/matrix with size rows x cols x channels corresponding to dataType ("+label+")"));
+  }
+
+  if(!channels){
+    channels = 1;
+  }
+
+  var rows = arr.length;
+  var cols = arr[0].length;
+
+  var mat = new cv.Matrix(rows, cols, type);
+
+  var n_bytes = bytes/8;
+  var buf = new Buffer(rows * cols * channels * n_bytes);
+
+  buf.fill(0);
+
+  var fnName = getBufferMethodName(bytes, dataType, os.endianness(), false)
+
+  for(var i=0;i<rows * cols * channels;i++){
+    var c = i%channels;
+    var r = Math.floor(i/channels);
+    var y = r%cols;
+    var x = Math.floor(r/cols);
+    buf[fnName](arr[x][y][c], i*n_bytes);
+  }
+
+  mat.put(buf);
+
+  return mat;
+}
+
+Matrix.prototype.toArray = function(){
+  var size = this.size();
+  var buf = this.getData();
+  var type = this.type();
+  var bytesAndChannels = getNumberOfBytesAndChannelsPerType(type);
+  var bytes = bytesAndChannels.bytes;
+  var channels = bytesAndChannels.channels || this.channels();
+  var dataType = bytesAndChannels.dataType;
+
+  var n_bytes = bytes/8;
+  var fnName = getBufferMethodName(bytes, dataType, os.endianness(), true)
+
+  var res = []
+  for(var i = 0; i < size[0]; i++){
+    var row = [];
+    for(var j = 0; j < size[1]; j++){
+      var channelsValues = [];
+      for(var k = 0; k < channels; k++){
+        var index = (i*size[1]+j)*channels+k;
+        channelsValues.push(buf[fnName](index*n_bytes));
+      }
+      row.push(channelsValues);
+    }
+    res.push(row);
+  }
+  return res;
+}
 
 ImageStream = cv.ImageStream = function(){
   this.writable = true;
@@ -148,6 +263,3 @@ var CASCADES = {
 Object.keys(CASCADES).forEach(function(k){
   cv[k] = path.resolve(__dirname, '../data', CASCADES[k])
 })
-
-
-

src/Constants.cc

@@ -96,6 +96,7 @@ void Constants::Init(Local<Object> target) {
   CONST_INT(CV_DIST_C);
   CONST_INT(CV_DIST_L1);
   CONST_INT(CV_DIST_L2);
+  CONST_INT(CV_DIST_USER);
 
   CONST_INT(CV_DIST_MASK_3);
   CONST_INT(CV_DIST_MASK_5);

src/Histogram.cc

@@ -0,0 +1,135 @@
+#include "Histogram.h"
+#include "Matrix.h"
+
+void Histogram::Init(Local<Object> target) {
+  Nan::Persistent<Object> inner;
+  Local<Object> obj = Nan::New<Object>();
+  inner.Reset(obj);
+
+  Nan::SetMethod(obj, "calcHist", CalcHist);
+  Nan::SetMethod(obj, "emd", Emd);
+
+  target->Set(Nan::New("histogram").ToLocalChecked(), obj);
+}
+
+NAN_METHOD(Histogram::CalcHist) {
+  Nan::EscapableHandleScope scope;
+
+  try {
+    // Arg 0 is the image
+    Matrix* m0 = Nan::ObjectWrap::Unwrap<Matrix>(info[0]->ToObject());
+    cv::Mat inputImage = m0->mat;
+
+    // Arg 1 is the channel
+    Local<Array> nodeChannels = Local<Array>::Cast(info[1]->ToObject());
+    const unsigned int dims = nodeChannels->Length();
+    int channels[dims];
+    for (unsigned int i = 0; i < dims; i++) {
+      channels[i] = nodeChannels->Get(i)->IntegerValue();
+    }
+
+    // Arg 2 is histogram sizes in each dimension
+    Local<Array> nodeHistSizes = Local<Array>::Cast(info[2]->ToObject());
+    int histSize[dims];
+    for (unsigned int i = 0; i < dims; i++) {
+      histSize[i] = nodeHistSizes->Get(i)->IntegerValue();
+    }
+
+    // Arg 3 is array of the histogram bin boundaries in each dimension
+    Local<Array> nodeRanges = Local<Array>::Cast(info[3]->ToObject());
+    /// Set the ranges ( for B,G,R) )
+    float histRanges[dims][2];
+    const float* ranges[dims];
+
+    for (unsigned int i = 0; i < dims; i++) {
+      Local<Array> nodeRange = Local<Array>::Cast(nodeRanges->Get(i)->ToObject());
+      float lower = nodeRange->Get(0)->NumberValue();
+      float higher = nodeRange->Get(1)->NumberValue();
+      histRanges[i][0] = lower;
+      histRanges[i][1] = higher;
+      ranges[i] = histRanges[i];
+    }
+
+    // Arg 4 is uniform flag
+    bool uniform = info[4]->BooleanValue();
+
+    // Make a mat to hold the result image
+    cv::Mat outputHist;
+
+    // Perform calcHist
+    cv::calcHist(&inputImage, 1, channels, cv::Mat(), outputHist, dims, histSize, ranges, uniform);
+
+    v8::Local<v8::Array> arr = Nan::New<Array>(histSize[0]);
+
+    if(dims < 1 || dims > 3){
+      return Nan::ThrowTypeError("OPENCV nodejs binding error : only dimensions from 1 to 3 are allowed");
+    }
+
+    for (unsigned int i=0; i < (unsigned int) histSize[0]; i++) {
+      if(dims <= 1){
+        arr->Set(i, Nan::New<Number>(outputHist.at<float>(i)));
+      } else {
+        v8::Local<v8::Array> arr2 = Nan::New<Array>(dims);
+        for (unsigned int j=0; j < (unsigned int) histSize[1]; j++) {
+          if(dims <= 2){
+            arr2->Set(j, Nan::New<Number>(outputHist.at<float>(i,j)));
+          } else {
+            v8::Local<v8::Array> arr3 = Nan::New<Array>(dims);
+            for (unsigned int k=0; k < (unsigned int) histSize[1]; k++) {
+              arr3->Set(k, Nan::New<Number>(outputHist.at<float>(i,j,k)));
+            }
+            arr2->Set(j, arr3);
+          }
+        }
+        arr->Set(i, arr2);
+      }
+    }
+
+    info.GetReturnValue().Set(arr);
+  } catch (cv::Exception &e) {
+    const char *err_msg = e.what();
+    Nan::ThrowError(err_msg);
+    return;
+  }
+}
+
+// cv::distanceTransform
+NAN_METHOD(Histogram::Emd) {
+  Nan::EscapableHandleScope scope;
+
+  try {
+    // Arg 0 is the first signature
+    //std::vector<std::vector<float>> sig1 = nodeArrayToVec(info[0]->ToObject());
+    Matrix* m0 = Nan::ObjectWrap::Unwrap<Matrix>(info[0]->ToObject());
+    cv::Mat sig1 = m0->mat;
+
+    // Arg 1 is the second signature
+    //std::vector<std::vector<float>> sig2 = nodeArrayToVec(info[1]->ToObject());
+    Matrix* m1 = Nan::ObjectWrap::Unwrap<Matrix>(info[1]->ToObject());
+    cv::Mat sig2 = m1->mat;
+
+    // Arg 2 is the distance type
+    int distType = info[2]->IntegerValue();
+
+    float emd;
+
+    // Arg 3 is the cost matrix
+    if (info.Length() > 3) {
+      Matrix* m3 = Nan::ObjectWrap::Unwrap<Matrix>(info[3]->ToObject());
+      cv::Mat costs = m3->mat;
+
+      emd = cv::EMD(sig1, sig2, distType, costs);
+      info.GetReturnValue().Set(emd);
+    } else {
+      emd = cv::EMD(sig1, sig2, distType);
+    }
+
+    //printf("similarity %5.5f %%\n, DistanceType is %i\n", (1-emd)*100, distType);
+    info.GetReturnValue().Set(emd);
+
+  } catch (cv::Exception &e) {
+    const char *err_msg = e.what();
+    Nan::ThrowError(err_msg);
+    return;
+  }
+}

src/Histogram.h

@@ -0,0 +1,16 @@
+#ifndef __NODE_HISTOGRAM_H
+#define __NODE_HISTOGRAM_H
+
+#include "OpenCV.h"
+
+/**
+ * Implementation of histogram.hpp functions
+ */
+class Histogram: public Nan::ObjectWrap {
+public:
+  static void Init(Local<Object> target);
+  static NAN_METHOD(CalcHist);
+  static NAN_METHOD(Emd);  
+};
+
+#endif

src/Matrix.cc

@@ -117,6 +117,7 @@ void Matrix::Init(Local<Object> target) {
   Nan::SetPrototypeMethod(ctor, "release", Release);
   Nan::SetPrototypeMethod(ctor, "subtract", Subtract);
   Nan::SetPrototypeMethod(ctor, "compare", Compare);
+  Nan::SetPrototypeMethod(ctor, "mul", Mul);
 
   target->Set(Nan::New("Matrix").ToLocalChecked(), ctor->GetFunction());
 };
@@ -2853,7 +2854,23 @@ NAN_METHOD(Matrix::Compare) {
   cv::Mat res = cv::Mat(width, height, CV_8UC1);
 
   cv::compare(self->mat, other->mat, res, cmpop);
-
+  Local<Object> out = Nan::NewInstance(Nan::GetFunction(Nan::New(Matrix::constructor)).ToLocalChecked()).ToLocalChecked();
+  Matrix *m_out = Nan::ObjectWrap::Unwrap<Matrix>(out);
+  m_out->mat = res;
+
+  info.GetReturnValue().Set(out);
+  return;
+}
+NAN_METHOD(Matrix::Mul) {
+  SETUP_FUNCTION(Matrix)
+
+  if (info.Length() < 1) {
+    Nan::ThrowTypeError("Invalid number of arguments");
+  }
+
+  Matrix *other = Nan::ObjectWrap::Unwrap<Matrix>(info[0]->ToObject());
+
+  cv::Mat res = self->mat.mul(other->mat);
   Local<Object> out = Nan::NewInstance(Nan::GetFunction(Nan::New(Matrix::constructor)).ToLocalChecked()).ToLocalChecked();
   Matrix *m_out = Nan::ObjectWrap::Unwrap<Matrix>(out);
   m_out->mat = res;

src/Matrix.h

@@ -135,6 +135,7 @@ public:
 
   JSFUNC(Subtract)
   JSFUNC(Compare)
+  JSFUNC(Mul)
   /*
    static Handle<Value> Val(const Arguments& info);
    static Handle<Value> RowRange(const Arguments& info);

src/init.cc

@@ -15,6 +15,7 @@
 #include "Stereo.h"
 #include "BackgroundSubtractor.h"
 #include "LDAWrap.h"
+#include "Histogram.h"
 
 extern "C" void init(Local<Object> target) {
   Nan::HandleScope scope;
@@ -30,6 +31,7 @@ extern "C" void init(Local<Object> target) {
   Constants::Init(target);
   Calib3D::Init(target);
   ImgProc::Init(target);
+  Histogram::Init(target);
 #if CV_MAJOR_VERSION < 3
   StereoBM::Init(target);
   StereoSGBM::Init(target);

test/unit.js

@@ -398,15 +398,16 @@ test('Mean', function(assert) {
 });
 
 test('Compare', function(assert) {
-  var b = new cv.Matrix.Zeros(2, 2, cv.Constants.CV_8UC1);
+  var a = cv.Matrix.fromArray([[[0],[-20]],[[2],[-18]]], cv.Constants.CV_8SC1);
-  var a = new cv.Matrix.Zeros(2, 2, cv.Constants.CV_8UC1);
+  var b = cv.Matrix.fromArray([[[3],[-20]],[[0],[-16]]], cv.Constants.CV_8SC1);
 
-  a.set(0, 0, 3);
+  var compare1 = a.compare(b, cv.Constants.CMP_EQ);
+  var compare2 = a.compare(b, cv.Constants.CMP_GT);
+  var compare3 = a.compare(b, cv.Constants.CMP_LE);
 
-  var compare = a.compare(b, cv.Constants.CMP_EQ);
+  assert.deepEqual(compare1.toArray(), [[[0],[255]],[[0],[0]]]);
-  var buf = compare.getData();
+  assert.deepEqual(compare2.toArray(), [[[0],[0]],[[255],[0]]]);
-  compare.save("./test.png");
+  assert.deepEqual(compare3.toArray(), [[[255],[255]],[[0],[255]]]);
-  console.log(compare.norm());
 
   assert.end();
 });
@@ -463,5 +464,24 @@ test('setColor works will alpha channels', function(assert) {
   });
 });
 
+test('toArray/fromArray working in both ways', function(assert) {
+  var cv = require('../lib/opencv');
+
+  cv.readImage("./examples/files/mona.png", function(err, orig) {
+    if (err) throw err;
+
+    var a = orig.toArray();
+    var type = orig.type();
+    var doubleConversion = cv.Matrix.fromArray(a, type).toArray();
+
+    var randomI = Math.floor(Math.random()*a.length)
+    var randomJ = Math.floor(Math.random()*a[randomI].length)
+    var randomK = Math.floor(Math.random()*a[randomI][randomJ].length)
+
+    assert.equal(a[randomI][randomJ][randomK], doubleConversion[randomI][randomJ][randomK]);
+    assert.end();
+  });
+});
+
 // Test the examples folder.
 require('./examples')()