Added noise reduction module (#1105)

* Added Noise Removal Module

* Remove ChangePixel Function

src/Modules.js

@@ -31,6 +31,7 @@ module.exports = {
   'invert': require('image-sequencer-invert'),
   'ndvi': require('./modules/Ndvi'),
   'ndvi-colormap': require('./modules/NdviColormap'),
+  'noise-reduction': require('./modules/NoiseReduction'),
   'paint-bucket': require('./modules/PaintBucket'),
   'overlay': require('./modules/Overlay'),
   'replace-color': require('./modules/ReplaceColor'),

src/modules/NoiseReduction/Module.js

@@ -0,0 +1,38 @@
+module.exports = function NoiseReduction(options, UI){
+  var defaults = require('./../../util/getDefaults.js')(require('./info.json'));
+  var output;
+  
+  function draw(input,callback,progressObj){
+  
+    progressObj.stop(true);
+    progressObj.overrideFlag = true;
+  
+    var step = this;
+    options.method = options.method || defaults.method;
+  
+    function extraManipulation(pixels) {
+      pixels = require('./NoiseReduction.js')(pixels, options.method);
+      return pixels;
+    }
+  
+    function output(image,  datauri, mimetype){
+      // This output is accessible by Image Sequencer
+      step.output = { src: datauri, format: mimetype };
+  
+    }
+  
+    return require('../_nomodule/PixelManipulation.js')(input, {
+      output: output,
+      extraManipulation: extraManipulation,
+      format: input.format,
+      image: options.image,
+      callback: callback
+    });
+  }
+  return {
+    options: options,
+    draw: draw,
+    output: output,
+    UI: UI
+  };
+};

src/modules/NoiseReduction/NoiseReduction.js

@@ -0,0 +1,81 @@
+module.exports = function Noise(pixels, method) {
+  let neighbourX = [-1, -1, -1, 0, 0, 0, 1, 1, 1];
+  let neighbourY = [-1, 0, 1, -1, 0, 1, -1, 0, 1];
+
+  if(method == 'Median Filtering'){
+
+    for(let y = 0; y < pixels.shape[1]; y++){
+      for(let x = 0; x < pixels.shape[0]; x++){
+        let i = 0, k = 0, windowr = [],windowg = [], windowb = [];
+
+        while( k <= 8){
+          let newX = x + neighbourX[k], newY = y + neighbourY[k];
+  
+          if( newX >= 0 && newX < pixels.shape[0])
+          {
+            if( newY >= 0 && newY < pixels.shape[1]){
+              windowr[i] = pixels.get((newX),(newY),0);
+              windowg[i] = pixels.get((newX),(newY),1);
+              windowb[i] = pixels.get((newX),(newY),2);
+              i++;
+            }
+          }
+          k++;
+        }
+
+        windowr.sort();
+        windowg.sort();
+        windowb.sort();
+        
+        if(i%2 == 0)
+        {
+          let value = windowr[i/2] + windowr[(i/2)-1];
+          pixels.set(x,y,0,value);
+
+          value = windowg[i/2] + windowg[(i/2)-1];
+          pixels.set(x,y,1,value);
+
+          value = windowb[i/2] + windowb[(i/2)-1];
+          pixels.set(x,y,2,value);
+
+        }
+        else {
+          pixels.set(x, y, 0, windowr[Math.floor(i/2)]);
+          pixels.set(x, y, 1, windowg[Math.floor(i/2)]);
+          pixels.set(x, y, 2, windowb[Math.floor(i/2)]);
+
+        }
+      }
+    }
+  }
+  else if(method == 'Mean Filtering'){
+    
+    for(let y = 0; y < pixels.shape[1]; y++){
+      for(let x = 0; x < pixels.shape[0]; x++){
+        let i = 0, k = 0, sumR=0, sumG = 0, sumB =0;
+
+        while( k <= 8){
+          let newX = x + neighbourX[k], newY = y + neighbourY[k];
+
+          if( newX >= 0 && newX < pixels.shape[0])
+          {
+            if( newY >= 0 && newY < pixels.shape[1]){
+              sumR += pixels.get(newX,newY,0);
+              sumG += pixels.get(newX,newY,1);
+              sumB += pixels.get(newX,newY,2);
+              i++;
+            }
+          }
+          k++;
+        }
+
+        pixels.set(x, y, 0, sumR/i);
+        pixels.set(x, y, 1, sumG/i);
+        pixels.set(x, y, 2, sumB/i);
+
+      }
+    }
+  }
+  
+  return pixels;
+};

src/modules/NoiseReduction/index.js

@@ -0,0 +1,4 @@
+module.exports = [
+  require('./Module'),
+  require('./info.json')
+];

src/modules/NoiseReduction/info.json

@@ -0,0 +1,13 @@
+{
+    "name": "Noise Reduction",
+    "description": "Reduces noise from Image",
+    "inputs": {
+        "method": {
+            "type": "select",
+            "desc": "Select the noise filtering method",
+            "default": "Median Filtering",
+            "values": ["Mean Filtering","Median Filtering"]
+        }
+    },
+    "docs-link":""
+}

test/core/modules/noise-reduction.js

@@ -0,0 +1,4 @@
+const testModule = require('../templates/module-test'),
+  benchmark = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAAklEQVR4AewaftIAAAApSURBVKXBAQEAAAiDMKR/5xuC7QYjkEgiiSSSSCKJJJJIIokkkkgiiR5YbQIegx78CAAAAABJRU5ErkJggg==';
+
+testModule('noise-reduction', {method: 'Median Filtering'}, benchmark);