Colorbar added (#316)

* setup

Signed-off-by: tech4GT <varun.gupta1798@gmail.com>

* overlay done

Signed-off-by: tech4GT <varun.gupta1798@gmail.com>

* add colorbar fixes #285

Signed-off-by: tech4GT <varun.gupta1798@gmail.com>

* add inputs to colorbar

Signed-off-by: tech4GT <varun.gupta1798@gmail.com>

src/modules/Overlay/Module.js

@@ -0,0 +1,70 @@
+module.exports = function Dynamic(options, UI, util) {
+
+    options.x = options.x || 0;
+    options.y = options.y || 0;
+
+    var output;
+
+    // This function is called on every draw.
+    function draw(input, callback, progressObj) {
+
+        options.offset = options.offset || -2;
+
+        progressObj.stop(true);
+        progressObj.overrideFlag = true;
+
+        var step = this;
+
+        // save the pixels of the base image
+        var baseStepImage = this.getStep(options.offset).image;
+        var baseStepOutput = this.getOutput(options.offset);
+
+        var getPixels = require('get-pixels');
+
+        getPixels(input.src, function(err, pixels) {
+            options.secondImagePixels = pixels;
+
+            function changePixel(r1, g1, b1, a1, x, y) {
+
+                // overlay
+                var p = options.secondImagePixels;
+                if (x >= options.x
+                    && x < p.shape[0]
+                    && y >= options.y
+                    && y < p.shape[1])
+                    return [
+                        p.get(x, y, 0),
+                        p.get(x, y, 1),
+                        p.get(x, y, 2),
+                        p.get(x, y, 3)
+                    ];
+                else
+                    return [r1, g1, b1, a1];
+            }
+
+            function output(image, datauri, mimetype) {
+
+                // This output is accessible by Image Sequencer
+                step.output = { src: datauri, format: mimetype };
+
+            }
+
+            // run PixelManipulation on first Image pixels
+            return require('../_nomodule/PixelManipulation.js')(baseStepOutput, {
+                output: output,
+                changePixel: changePixel,
+                format: baseStepOutput.format,
+                image: baseStepImage,
+                inBrowser: options.inBrowser,
+                callback: callback
+            });
+        });
+    }
+
+    return {
+        options: options,
+        draw: draw,
+        output: output,
+        UI: UI
+    }
+}