cornerstone.js

/*! cornerstone - v0.7.3 - 2015-04-04 | (c) 2014 Chris Hafey | https://github.com/chafey/cornerstone */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    function disable(element) {
        if(element === undefined) {
            throw "disable: element element must not be undefined";
        }

        // Search for this element in this list of enabled elements
        var enabledElements = cornerstone.getEnabledElements();
        for(var i=0; i < enabledElements.length; i++) {
            if(enabledElements[i].element === element) {
                // We found it!

                // Fire an event so dependencies can cleanup
                var eventData = {
                    element : element
                };
                $(element).trigger("CornerstoneElementDisabled", eventData);

                // remove the child dom elements that we created (e.g.canvas)
                enabledElements[i].element.removeChild(enabledElements[i].canvas);

                // remove this element from the list of enabled elements
                enabledElements.splice(i, 1);
                return;
            }
        }
    }

    // module/private exports
    cornerstone.disable = disable;

    return cornerstone;
}(cornerstone));
/**
 * This module is responsible for enabling an element to display images with cornerstone
 */
var cornerstone = (function ($, cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * sets a new image object for a given element
     * @param element
     * @param image
     */
    function displayImage(element, image, viewport) {
        if(element === undefined) {
            throw "displayImage: parameter element cannot be undefined";
        }
        if(image === undefined) {
            throw "displayImage: parameter image cannot be undefined";
        }

        var enabledElement = cornerstone.getEnabledElement(element);

        enabledElement.image = image;

        if(enabledElement.viewport === undefined) {
            enabledElement.viewport = cornerstone.getDefaultViewport(enabledElement.canvas, image);
        }

        // merge viewport
        if(viewport) {
            for(var attrname in viewport)
            {
                if(viewport[attrname] !== null) {
                    enabledElement.viewport[attrname] = viewport[attrname];
                }
            }
        }

        var now = new Date();
        var frameRate;
        if(enabledElement.lastImageTimeStamp !== undefined) {
            var timeSinceLastImage = now.getTime() - enabledElement.lastImageTimeStamp;
            frameRate = (1000 / timeSinceLastImage).toFixed();
        } else {
        }
        enabledElement.lastImageTimeStamp = now.getTime();

        var newImageEventData = {
            viewport : enabledElement.viewport,
            element : enabledElement.element,
            image : enabledElement.image,
            enabledElement : enabledElement,
            frameRate : frameRate
        };

        $(enabledElement.element).trigger("CornerstoneNewImage", newImageEventData);

        cornerstone.updateImage(element);
    }

    // module/private exports
    cornerstone.displayImage = displayImage;

    return cornerstone;
}($, cornerstone));
/**
 * This module is responsible for immediately drawing an enabled element
 */

var cornerstone = (function ($, cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Immediately draws the enabled element
     *
     * @param element
     */
    function draw(element) {
        var enabledElement = cornerstone.getEnabledElement(element);

        if(enabledElement.image === undefined) {
            throw "draw: image has not been loaded yet";
        }

        cornerstone.drawImage(enabledElement);
    }

    // Module exports
    cornerstone.draw = draw;

    return cornerstone;
}($, cornerstone));
/**
 * This module is responsible for drawing an image to an enabled elements canvas element
 */

var cornerstone = (function ($, cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Internal API function to draw an image to a given enabled element
     * @param enabledElement
     * @param invalidated - true if pixel data has been invalidated and cached rendering should not be used
     */
    function drawImage(enabledElement, invalidated) {

        var start = new Date();

        enabledElement.image.render(enabledElement, invalidated);

        var context = enabledElement.canvas.getContext('2d');

        var end = new Date();
        var diff = end - start;
        //console.log(diff + ' ms');

        var eventData = {
            viewport : enabledElement.viewport,
            element : enabledElement.element,
            image : enabledElement.image,
            enabledElement : enabledElement,
            canvasContext: context,
            renderTimeInMs : diff
        };

        $(enabledElement.element).trigger("CornerstoneImageRendered", eventData);
        enabledElement.invalid = false;
    }

    // Module exports
    cornerstone.drawImage = drawImage;

    return cornerstone;
}($, cornerstone));
/**
 * This module is responsible for drawing invalidated enabled elements
 */

var cornerstone = (function ($, cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Draws all invalidated enabled elements and clears the invalid flag after drawing it
     */
    function drawInvalidated()
    {
        var enabledElements = cornerstone.getEnabledElements();
        for(var i=0;i < enabledElements.length; i++) {
            var ee = enabledElements[i];
            if(ee.invalid === true) {
                cornerstone.drawImage(ee);
            }
        }
    }

    // Module exports
    cornerstone.drawInvalidated = drawInvalidated;

    return cornerstone;
}($, cornerstone));
/**
 * This module is responsible for enabling an element to display images with cornerstone
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    function enable(element) {
        if(element === undefined) {
            throw "enable: parameter element cannot be undefined";
        }

        var canvas = document.createElement('canvas');
        element.appendChild(canvas);

        var el = {
            element: element,
            canvas: canvas,
            image : undefined, // will be set once image is loaded
            invalid: false, // true if image needs to be drawn, false if not
            data : {}
        };
        cornerstone.addEnabledElement(el);

        cornerstone.resize(element, true);

        return element;
    }

    // module/private exports
    cornerstone.enable = enable;

    return cornerstone;
}(cornerstone));
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    function getElementData(el, dataType) {
        var ee = cornerstone.getEnabledElement(el);
        if(ee.data.hasOwnProperty(dataType) === false)
        {
            ee.data[dataType] = {};
        }
        return ee.data[dataType];
    }

    function removeElementData(el, dataType) {
        var ee = cornerstone.getEnabledElement(el);
        delete ee.data[dataType];
    }

    // module/private exports
    cornerstone.getElementData = getElementData;
    cornerstone.removeElementData = removeElementData;

    return cornerstone;
}(cornerstone));
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    var enabledElements = [];

    function getEnabledElement(element) {
        if(element === undefined) {
            throw "getEnabledElement: parameter element must not be undefined";
        }
        for(var i=0; i < enabledElements.length; i++) {
            if(enabledElements[i].element == element) {
                return enabledElements[i];
            }
        }

        throw "element not enabled";
    }

    function addEnabledElement(enabledElement) {
        if(enabledElement === undefined) {
            throw "getEnabledElement: enabledElement element must not be undefined";
        }

        enabledElements.push(enabledElement);
    }

    function getEnabledElementsByImageId(imageId) {
        var ees = [];
        enabledElements.forEach(function(enabledElement) {
            if(enabledElement.image && enabledElement.image.imageId === imageId) {
                ees.push(enabledElement);
            }
        });
        return ees;
    }

    function getEnabledElements() {
        return enabledElements;
    }

    // module/private exports
    cornerstone.getEnabledElement = getEnabledElement;
    cornerstone.addEnabledElement = addEnabledElement;
    cornerstone.getEnabledElementsByImageId = getEnabledElementsByImageId;
    cornerstone.getEnabledElements = getEnabledElements;

    return cornerstone;
}(cornerstone));
/**
 * This module will fit an image to fit inside the canvas displaying it such that all pixels
 * in the image are viewable
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Adjusts an images scale and center so the image is centered and completely visible
     * @param element
     */
    function fitToWindow(element)
    {
        var enabledElement = cornerstone.getEnabledElement(element);
        var defaultViewport = cornerstone.getDefaultViewport(enabledElement.canvas, enabledElement.image);
        enabledElement.viewport.scale = defaultViewport.scale;
        enabledElement.viewport.translation.x = defaultViewport.translation.x;
        enabledElement.viewport.translation.y = defaultViewport.translation.y;
        enabledElement.viewport.rotation = defaultViewport.rotation;
        enabledElement.viewport.hflip = defaultViewport.hflip;
        enabledElement.viewport.vflip = defaultViewport.vflip;
        cornerstone.updateImage(element);
    }

    cornerstone.fitToWindow = fitToWindow;

    return cornerstone;
}(cornerstone));

/**
 * This module generates a lut for an image
 */

var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Creates a LUT used while rendering to convert stored pixel values to
     * display pixels
     *
     * @param image
     * @returns {Array}
     */
    function generateLut(image, windowWidth, windowCenter, invert)
    {
        if(image.lut === undefined) {
            image.lut =  new Int16Array(image.maxPixelValue - Math.min(image.minPixelValue,0)+1);
        }
        var lut = image.lut;

        var maxPixelValue = image.maxPixelValue;
        var minPixelValue = image.minPixelValue;
        var slope = image.slope;
        var intercept = image.intercept;
        var localWindowWidth = windowWidth;
        var localWindowCenter = windowCenter;

        var modalityLutValue;
        var voiLutValue;
        var clampedValue;
        var storedValue;

        // NOTE: As of Nov 2014, most javascript engines have lower performance when indexing negative indexes.
        // We improve performance by offsetting the pixel values for signed data to avoid negative indexes
        // when generating the lut and then undo it in storedPixelDataToCanvasImagedata.  Thanks to @jpambrun
        // for this contribution!

        var offset = 0;
        if(minPixelValue < 0) {
            offset = minPixelValue;
        }

        if(invert === true) {
            for(storedValue = image.minPixelValue; storedValue <= maxPixelValue; storedValue++)
            {
                modalityLutValue = storedValue * slope + intercept;
                voiLutValue = (((modalityLutValue - (localWindowCenter)) / (localWindowWidth) + 0.5) * 255.0);
                clampedValue = Math.min(Math.max(voiLutValue, 0), 255);
                lut[storedValue + (-offset)] = Math.round(255 - clampedValue);
            }
        }
        else {
            for(storedValue = image.minPixelValue; storedValue <= maxPixelValue; storedValue++)
            {
                modalityLutValue = storedValue * slope + intercept;
                voiLutValue = (((modalityLutValue - (localWindowCenter)) / (localWindowWidth) + 0.5) * 255.0);
                clampedValue = Math.min(Math.max(voiLutValue, 0), 255);
                lut[storedValue+ (-offset)] = Math.round(clampedValue);
            }
        }
    }


    // Module exports
    cornerstone.generateLut = generateLut;

    return cornerstone;
}(cornerstone));

/**
 * This module contains a function to get a default viewport for an image given
 * a canvas element to display it in
 *
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Creates a new viewport object containing default values for the image and canvas
     * @param canvas
     * @param image
     * @returns viewport object
     */
    function getDefaultViewport(canvas, image) {
        if(canvas === undefined) {
            throw "getDefaultViewport: parameter canvas must not be undefined";
        }
        if(image === undefined) {
            throw "getDefaultViewport: parameter image must not be undefined";
        }
        var viewport = {
            scale : 1.0,
            translation : {
                x : 0,
                y : 0
            },
            voi : {
                windowWidth: image.windowWidth,
                windowCenter: image.windowCenter,
            },
            invert: image.invert,
            pixelReplication: false,
            rotation: 0,
            hflip: false,
            vflip: false
        };

        // fit image to window
        var verticalScale = canvas.height / image.rows;
        var horizontalScale= canvas.width / image.columns;
        if(horizontalScale < verticalScale) {
            viewport.scale = horizontalScale;
        }
        else {
            viewport.scale = verticalScale;
        }
        return viewport;
    }

    // module/private exports
    cornerstone.getDefaultViewport = getDefaultViewport;

    return cornerstone;
}(cornerstone));

/**
 * This module returns a subset of the stored pixels of an image
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Returns an array of stored pixels given a rectangle in the image
     * @param element
     * @param x
     * @param y
     * @param width
     * @param height
     * @returns {Array}
     */
    function getStoredPixels(element, x, y, width, height) {
        if(element === undefined) {
            throw "getStoredPixels: parameter element must not be undefined";
        }

        x = Math.round(x);
        y = Math.round(y);
        var ee = cornerstone.getEnabledElement(element);
        var storedPixels = [];
        var index = 0;
        var pixelData = ee.image.getPixelData();
        for(var row=0; row < height; row++) {
            for(var column=0; column < width; column++) {
                var spIndex = ((row + y) * ee.image.columns) + (column + x);
                storedPixels[index++] = pixelData[spIndex];
            }
        }
        return storedPixels;
    }

    /**
     * Returns array of pixels with modality LUT transformation applied
     */
    function getPixels(element, x, y, width, height) {

        var storedPixels = getStoredPixels(element, x, y, width, height);
        var ee = cornerstone.getEnabledElement(element);
        var slope = ee.image.slope;
        var intercept = ee.image.intercept;

        var modalityPixels = storedPixels.map(function(pixel){
                return pixel * slope + intercept;
            });

        return modalityPixels;
    }

    // module exports
    cornerstone.getStoredPixels = getStoredPixels;
    cornerstone.getPixels = getPixels;

    return cornerstone;
}(cornerstone));
/**
 * This module deals with caching images
 */

var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    var imageCache = {
    };

    var cachedImages = [];

    var maximumSizeInBytes = 1024 * 1024 * 1024; // 1 GB
    var cacheSizeInBytes = 0;

    function setMaximumSizeBytes(numBytes)
    {
        if(numBytes === undefined) {
            throw "setMaximumSizeBytes: parameter numBytes must not be undefined";
        }
        if(numBytes.toFixed === undefined) {
            throw "setMaximumSizeBytes: parameter numBytes must be a number";
        }

        maximumSizeInBytes = numBytes;
        purgeCacheIfNecessary();
    }

    function purgeCacheIfNecessary()
    {
        // if max cache size has not been exceeded, do nothing
        if(cacheSizeInBytes <= maximumSizeInBytes)
        {
            return;
        }

        // cache size has been exceeded, create list of images sorted by timeStamp
        // so we can purge the least recently used image
        function compare(a,b) {
            if(a.timeStamp > b.timeStamp) {
                return -1;
            }
            if(a.timeStamp < b.timeStamp) {
                return 1;
            }
            return 0;
        }
        cachedImages.sort(compare);

        // remove images as necessary
        while(cacheSizeInBytes > maximumSizeInBytes)
        {
            var lastCachedImage = cachedImages[cachedImages.length - 1];
            cacheSizeInBytes -= lastCachedImage.sizeInBytes;
            delete imageCache[lastCachedImage.imageId];
            lastCachedImage.imagePromise.reject();
            cachedImages.pop();
        }
    }

    function putImagePromise(imageId, imagePromise) {
        if(imageId === undefined)
        {
            throw "getImagePromise: imageId must not be undefined";
        }
        if(imagePromise === undefined)
        {
            throw "getImagePromise: imagePromise must not be undefined";
        }

        if(imageCache.hasOwnProperty(imageId) === true) {
            throw "putImagePromise: imageId already in cache";
        }

        var cachedImage = {
            loaded : false,
            imageId : imageId,
            imagePromise : imagePromise,
            timeStamp : new Date(),
            sizeInBytes: 0
        };

        imageCache[imageId] = cachedImage;
        cachedImages.push(cachedImage);

        imagePromise.then(function(image) {
            cachedImage.loaded = true;

            if(image.sizeInBytes === undefined)
            {
                throw "putImagePromise: image does not have sizeInBytes property or";
            }
            if(image.sizeInBytes.toFixed === undefined) {
                throw "putImagePromise: image.sizeInBytes is not a number";
            }
            cachedImage.sizeInBytes = image.sizeInBytes;
            cacheSizeInBytes += cachedImage.sizeInBytes;
            purgeCacheIfNecessary();
        });
    }

    function getImagePromise(imageId) {
        if(imageId === undefined)
        {
            throw "getImagePromise: imageId must not be undefined";
        }
        var cachedImage = imageCache[imageId];
        if(cachedImage === undefined) {
            return undefined;
        }

        // bump time stamp for cached image
        cachedImage.timeStamp = new Date();
        return cachedImage.imagePromise;
    }

    function removeImagePromise(imageId) {
        if(imageId === undefined) {
            throw "removeImagePromise: imageId must not be undefined";
        }
        var cachedImage = imageCache[imageId];
        if(cachedImage === undefined) {
            throw "removeImagePromise: imageId must not be undefined";
        }
        cachedImages.splice( cachedImages.indexOf(cachedImage), 1);
        cacheSizeInBytes -= cachedImage.sizeInBytes;
        delete imageCache[imageId];

        return cachedImage.imagePromise;
    }

    function getCacheInfo() {
        return {
            maximumSizeInBytes : maximumSizeInBytes,
            cacheSizeInBytes : cacheSizeInBytes,
            numberOfImagesCached: cachedImages.length
        };
    }

    function purgeCache() {
        while (cachedImages.length > 0) {
            var removedCachedImage = cachedImages.pop();
            delete imageCache[removedCachedImage.imageId];
            removedCachedImage.imagePromise.reject();
        }
        cacheSizeInBytes = 0;
    }

    // module exports

    cornerstone.imageCache = {
        putImagePromise : putImagePromise,
        getImagePromise: getImagePromise,
        removeImagePromise: removeImagePromise,
        setMaximumSizeBytes: setMaximumSizeBytes,
        getCacheInfo : getCacheInfo,
        purgeCache: purgeCache
    };

    return cornerstone;
}(cornerstone));

/**
 * This module deals with ImageLoaders, loading images and caching images
 */

var cornerstone = (function ($, cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    var imageLoaders = {};

    var unknownImageLoader;

    function loadImageFromImageLoader(imageId) {
        var colonIndex = imageId.indexOf(":");
        var scheme = imageId.substring(0, colonIndex);
        var loader = imageLoaders[scheme];
        var imagePromise;
        if(loader === undefined || loader === null) {
            if(unknownImageLoader !== undefined) {
                imagePromise = unknownImageLoader(imageId);
                return imagePromise;
            }
            else {
                return undefined;
            }
        }
        imagePromise = loader(imageId);

        // broadcast an image loaded event once the image is loaded
        // This is based on the idea here: http://stackoverflow.com/questions/3279809/global-custom-events-in-jquery
        imagePromise.then(function(image) {
            $(cornerstone).trigger('CornerstoneImageLoaded', {image: image});
        });

        return imagePromise;
    }

    // Loads an image given an imageId and returns a promise which will resolve
    // to the loaded image object or fail if an error occurred.  The loaded image
    // is not stored in the cache
    function loadImage(imageId) {
        if(imageId === undefined) {
            throw "loadImage: parameter imageId must not be undefined";
        }

        var imagePromise = cornerstone.imageCache.getImagePromise(imageId);
        if(imagePromise !== undefined) {
            return imagePromise;
        }

        imagePromise = loadImageFromImageLoader(imageId);
        if(imagePromise === undefined) {
            throw "loadImage: no image loader for imageId";
        }

        return imagePromise;
    }

    // Loads an image given an imageId and returns a promise which will resolve
    // to the loaded image object or fail if an error occurred.  The image is
    // stored in the cache
    function loadAndCacheImage(imageId) {
        if(imageId === undefined) {
            throw "loadAndCacheImage: parameter imageId must not be undefined";
        }

        var imagePromise = cornerstone.imageCache.getImagePromise(imageId);
        if(imagePromise !== undefined) {
            return imagePromise;
        }

        imagePromise = loadImageFromImageLoader(imageId);
        if(imagePromise === undefined) {
            throw "loadAndCacheImage: no image loader for imageId";
        }

        cornerstone.imageCache.putImagePromise(imageId, imagePromise);

        return imagePromise;
    }


    // registers an imageLoader plugin with cornerstone for the specified scheme
    function registerImageLoader(scheme, imageLoader) {
        imageLoaders[scheme] = imageLoader;
    }

    // Registers a new unknownImageLoader and returns the previous one (if it exists)
    function registerUnknownImageLoader(imageLoader) {
        var oldImageLoader = unknownImageLoader;
        unknownImageLoader = imageLoader;
        return oldImageLoader;
    }

    // module exports

    cornerstone.loadImage = loadImage;
    cornerstone.loadAndCacheImage = loadAndCacheImage;
    cornerstone.registerImageLoader = registerImageLoader;
    cornerstone.registerUnknownImageLoader = registerUnknownImageLoader;

    return cornerstone;
}($, cornerstone));
/**
 * This module contains a function to make an image is invalid
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Sets the invalid flag on the enabled element and fire an event
     * @param element
     */
    function invalidate(element) {
        var enabledElement = cornerstone.getEnabledElement(element);
        enabledElement.invalid = true;
        var eventData = {
            element: element
        };
        $(enabledElement.element).trigger("CornerstoneInvalidated", eventData);
    }

    // module exports
    cornerstone.invalidate = invalidate;

    return cornerstone;
}(cornerstone));
/**
 * This module contains a function to immediately invalidate an image
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Forces the image to be updated/redrawn for the specified enabled element
     * @param element
     */
    function invalidateImageId(imageId) {

        var enabledElements = cornerstone.getEnabledElementsByImageId(imageId);
        enabledElements.forEach(function(enabledElement) {
            cornerstone.drawImage(enabledElement, true);
        });
    }

    // module exports
    cornerstone.invalidateImageId = invalidateImageId;

    return cornerstone;
}(cornerstone));
/**
 * This module contains a helper function to covert page coordinates to pixel coordinates
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Converts a point in the page coordinate system to the pixel coordinate
     * system
     * @param element
     * @param pageX
     * @param pageY
     * @returns {{x: number, y: number}}
     */

    function pageToPixel(element, pageX, pageY) {
        var ee = cornerstone.getEnabledElement(element);

        if(ee.image === undefined) {
            throw "image has not been loaded yet";
        }

        // TODO: replace this with a transformation matrix

        // convert the pageX and pageY to the canvas client coordinates
        var rect = element.getBoundingClientRect();
        var clientX = pageX - rect.left - window.pageXOffset;
        var clientY = pageY - rect.top - window.pageYOffset;

        // translate the client relative to the middle of the canvas
        var middleX = clientX - rect.width / 2.0;
        var middleY = clientY - rect.height / 2.0;

        // scale to image coordinates middleX/middleY
        var viewport = ee.viewport;

        // apply the scale
        var widthScale = ee.viewport.scale;
        var heightScale = ee.viewport.scale;
        if(ee.image.rowPixelSpacing < ee.image.columnPixelSpacing) {
            widthScale = widthScale * (ee.image.columnPixelSpacing / ee.image.rowPixelSpacing);
        }
        else if(ee.image.columnPixelSpacing < ee.image.rowPixelSpacing) {
            heightScale = heightScale * (ee.image.rowPixelSpacing / ee.image.columnPixelSpacing);
        }

        var scaledMiddleX = middleX / widthScale;
        var scaledMiddleY = middleY / heightScale;

        // apply pan offset
        var imageX = scaledMiddleX - viewport.translation.x;
        var imageY = scaledMiddleY - viewport.translation.y;
        
        //Apply Flips        
        if(viewport.hflip) {
			imageX*=-1;
        }	
        
        if(viewport.vflip) {
			imageY*=-1;
        } 
        
		//Apply rotations
		if(viewport.rotation!==0) {
			var angle = viewport.rotation * Math.PI/180;		
	
			var cosA = Math.cos(angle);
			var sinA = Math.sin(angle);
	
			var newX = imageX * cosA - imageY * sinA;
			var newY = imageX * sinA + imageY * cosA;
				
			if(viewport.rotation===90 || viewport.rotation===270 || viewport.rotation===-90 || viewport.rotation===-270) {
				newX*= -1;
				newY*= -1;
			}  
	
			imageX = newX;
			imageY = newY;
		}    

        // translate to image top left
        imageX += ee.image.columns / 2;
        imageY += ee.image.rows / 2;

        return {
            x: imageX,
            y: imageY
        };
    }

    // module/private exports
    cornerstone.pageToPixel = pageToPixel;

    return cornerstone;
}(cornerstone));

/**
 * This module is responsible for drawing an image to an enabled elements canvas element
 */

var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    var colorRenderCanvas = document.createElement('canvas');
    var colorRenderCanvasContext;
    var colorRenderCanvasData;

    var lastRenderedImageId;
    var lastRenderedViewport = {};

    function initializeColorRenderCanvas(image)
    {
        // Resize the canvas
        colorRenderCanvas.width = image.width;
        colorRenderCanvas.height = image.height;

        // get the canvas data so we can write to it directly
        colorRenderCanvasContext = colorRenderCanvas.getContext('2d');
        colorRenderCanvasContext.fillStyle = 'white';
        colorRenderCanvasContext.fillRect(0,0, colorRenderCanvas.width, colorRenderCanvas.height);
        colorRenderCanvasData = colorRenderCanvasContext.getImageData(0,0,image.width, image.height);
    }


    function getLut(image, viewport)
    {
        // if we have a cached lut and it has the right values, return it immediately
        if(image.lut !== undefined &&
            image.lut.windowCenter === viewport.voi.windowCenter &&
            image.lut.windowWidth === viewport.voi.windowWidth &&
            image.lut.invert === viewport.invert) {
            return image.lut;
        }

        // lut is invalid or not present, regenerate it and cache it
        cornerstone.generateLut(image, viewport.voi.windowWidth, viewport.voi.windowCenter, viewport.invert);
        image.lut.windowWidth = viewport.voi.windowWidth;
        image.lut.windowCenter = viewport.voi.windowCenter;
        image.lut.invert = viewport.invert;
        return image.lut;
    }

    function doesImageNeedToBeRendered(enabledElement, image)
    {
        if(image.imageId !== lastRenderedImageId ||
            lastRenderedViewport.windowCenter !== enabledElement.viewport.voi.windowCenter ||
            lastRenderedViewport.windowWidth !== enabledElement.viewport.voi.windowWidth ||
            lastRenderedViewport.invert !== enabledElement.viewport.invert ||
            lastRenderedViewport.rotation !== enabledElement.viewport.rotation ||  
            lastRenderedViewport.hflip !== enabledElement.viewport.hflip ||
            lastRenderedViewport.vflip !== enabledElement.viewport.vflip
            )
        {
            return true;
        }

        return false;
    }

    function getRenderCanvas(enabledElement, image, invalidated)
    {
        // apply the lut to the stored pixel data onto the render canvas

        if(enabledElement.viewport.voi.windowWidth === enabledElement.image.windowWidth &&
            enabledElement.viewport.voi.windowCenter === enabledElement.image.windowCenter &&
            enabledElement.viewport.invert === false)
        {
            // the color image voi/invert has not been modified, request the canvas that contains
            // it so we can draw it directly to the display canvas
            return image.getCanvas();
        }
        else
        {
            if(doesImageNeedToBeRendered(enabledElement, image) === false && invalidated !== true) {
                return colorRenderCanvas;
            }

            // If our render canvas does not match the size of this image reset it
            // NOTE: This might be inefficient if we are updating multiple images of different
            // sizes frequently.
            if(colorRenderCanvas.width !== image.width || colorRenderCanvas.height != image.height) {
                initializeColorRenderCanvas(image);
            }

            // get the lut to use
            var colorLut = getLut(image, enabledElement.viewport);

            // the color image voi/invert has been modified - apply the lut to the underlying
            // pixel data and put it into the renderCanvas
            cornerstone.storedColorPixelDataToCanvasImageData(image, colorLut, colorRenderCanvasData.data);
            colorRenderCanvasContext.putImageData(colorRenderCanvasData, 0, 0);
            return colorRenderCanvas;
        }
    }

    /**
     * API function to render a color image to an enabled element
     * @param enabledElement
     * @param invalidated - true if pixel data has been invaldiated and cached rendering should not be used
     */
    function renderColorImage(enabledElement, invalidated) {

        if(enabledElement === undefined) {
            throw "drawImage: enabledElement parameter must not be undefined";
        }
        var image = enabledElement.image;
        if(image === undefined) {
            throw "drawImage: image must be loaded before it can be drawn";
        }

        // get the canvas context and reset the transform
        var context = enabledElement.canvas.getContext('2d');
        context.setTransform(1, 0, 0, 1, 0, 0);

        // clear the canvas
        context.fillStyle = 'black';
        context.fillRect(0,0, enabledElement.canvas.width, enabledElement.canvas.height);

        // turn off image smooth/interpolation if pixelReplication is set in the viewport
        if(enabledElement.viewport.pixelReplication === true) {
            context.imageSmoothingEnabled = false;
            context.mozImageSmoothingEnabled = false; // firefox doesn't support imageSmoothingEnabled yet
        }
        else {
            context.imageSmoothingEnabled = true;
            context.mozImageSmoothingEnabled = true;
        }

        // save the canvas context state and apply the viewport properties
        context.save();
        cornerstone.setToPixelCoordinateSystem(enabledElement, context);

        var renderCanvas = getRenderCanvas(enabledElement, image, invalidated);

        context.drawImage(renderCanvas, 0,0, image.width, image.height, 0, 0, image.width, image.height);

        context.restore();

        lastRenderedImageId = image.imageId;
        lastRenderedViewport.windowCenter = enabledElement.viewport.voi.windowCenter;
        lastRenderedViewport.windowWidth = enabledElement.viewport.voi.windowWidth;
        lastRenderedViewport.invert = enabledElement.viewport.invert;
        lastRenderedViewport.rotation = enabledElement.viewport.rotation;
        lastRenderedViewport.hflip = enabledElement.viewport.hflip;
        lastRenderedViewport.vflip = enabledElement.viewport.vflip;
    }

    // Module exports
    cornerstone.renderColorImage = renderColorImage;

    return cornerstone;
}(cornerstone));

/**
 * This module is responsible for drawing a grayscale imageß
 */

var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    var grayscaleRenderCanvas = document.createElement('canvas');
    var grayscaleRenderCanvasContext;
    var grayscaleRenderCanvasData;

    var lastRenderedImageId;
    var lastRenderedViewport = {};

    function initializeGrayscaleRenderCanvas(image)
    {
        // Resize the canvas
        grayscaleRenderCanvas.width = image.width;
        grayscaleRenderCanvas.height = image.height;

        // NOTE - we need to fill the render canvas with white pixels since we control the luminance
        // using the alpha channel to improve rendering performance.
        grayscaleRenderCanvasContext = grayscaleRenderCanvas.getContext('2d');
        grayscaleRenderCanvasContext.fillStyle = 'white';
        grayscaleRenderCanvasContext.fillRect(0,0, grayscaleRenderCanvas.width, grayscaleRenderCanvas.height);
        grayscaleRenderCanvasData = grayscaleRenderCanvasContext.getImageData(0,0,image.width, image.height);
    }

    function getLut(image, viewport, invalidated)
    {
        // if we have a cached lut and it has the right values, return it immediately
        if(image.lut !== undefined &&
            image.lut.windowCenter === viewport.voi.windowCenter &&
            image.lut.windowWidth === viewport.voi.windowWidth &&
            image.lut.invert === viewport.invert &&
            invalidated !== true) {
            return image.lut;
        }

        // lut is invalid or not present, regenerate it and cache it
        cornerstone.generateLut(image, viewport.voi.windowWidth, viewport.voi.windowCenter, viewport.invert);
        image.lut.windowWidth = viewport.voi.windowWidth;
        image.lut.windowCenter = viewport.voi.windowCenter;
        image.lut.invert = viewport.invert;
        return image.lut;
    }

    function doesImageNeedToBeRendered(enabledElement, image)
    {
        if(image.imageId !== lastRenderedImageId ||
            lastRenderedViewport.windowCenter !== enabledElement.viewport.voi.windowCenter ||
            lastRenderedViewport.windowWidth !== enabledElement.viewport.voi.windowWidth ||
            lastRenderedViewport.invert !== enabledElement.viewport.invert ||
            lastRenderedViewport.rotation !== enabledElement.viewport.rotation ||
            lastRenderedViewport.hflip !== enabledElement.viewport.hflip ||
            lastRenderedViewport.vflip !== enabledElement.viewport.vflip
            )
        {
            return true;
        }

        return false;
    }

    function getRenderCanvas(enabledElement, image, invalidated)
    {
        // apply the lut to the stored pixel data onto the render canvas

        if(doesImageNeedToBeRendered(enabledElement, image) === false && invalidated !== true) {
            return grayscaleRenderCanvas;
        }

        // If our render canvas does not match the size of this image reset it
        // NOTE: This might be inefficient if we are updating multiple images of different
        // sizes frequently.
        if(grayscaleRenderCanvas.width !== image.width || grayscaleRenderCanvas.height != image.height) {
            initializeGrayscaleRenderCanvas(image);
        }

        // get the lut to use
        var lut = getLut(image, enabledElement.viewport, invalidated);
        // gray scale image - apply the lut and put the resulting image onto the render canvas
        cornerstone.storedPixelDataToCanvasImageData(image, lut, grayscaleRenderCanvasData.data);
        grayscaleRenderCanvasContext.putImageData(grayscaleRenderCanvasData, 0, 0);
        return grayscaleRenderCanvas;
    }

    /**
     * API function to draw a grayscale image to a given enabledElement
     * @param enabledElement
     * @param invalidated - true if pixel data has been invaldiated and cached rendering should not be used
     */
    function renderGrayscaleImage(enabledElement, invalidated) {

        if(enabledElement === undefined) {
            throw "drawImage: enabledElement parameter must not be undefined";
        }
        var image = enabledElement.image;
        if(image === undefined) {
            throw "drawImage: image must be loaded before it can be drawn";
        }

        // get the canvas context and reset the transform
        var context = enabledElement.canvas.getContext('2d');
        context.setTransform(1, 0, 0, 1, 0, 0);

        // clear the canvas
        context.fillStyle = 'black';
        context.fillRect(0,0, enabledElement.canvas.width, enabledElement.canvas.height);

        // turn off image smooth/interpolation if pixelReplication is set in the viewport
        if(enabledElement.viewport.pixelReplication === true) {
            context.imageSmoothingEnabled = false;
            context.mozImageSmoothingEnabled = false; // firefox doesn't support imageSmoothingEnabled yet
        }
        else {
            context.imageSmoothingEnabled = true;
            context.mozImageSmoothingEnabled = true;
        }

        // save the canvas context state and apply the viewport properties
        cornerstone.setToPixelCoordinateSystem(enabledElement, context);

        var renderCanvas = getRenderCanvas(enabledElement, image, invalidated);

        // Draw the render canvas half the image size (because we set origin to the middle of the canvas above)
        context.drawImage(renderCanvas, 0,0, image.width, image.height, 0, 0, image.width, image.height);

        lastRenderedImageId = image.imageId;
        lastRenderedViewport.windowCenter = enabledElement.viewport.voi.windowCenter;
        lastRenderedViewport.windowWidth = enabledElement.viewport.voi.windowWidth;
        lastRenderedViewport.invert = enabledElement.viewport.invert;
        lastRenderedViewport.rotation = enabledElement.viewport.rotation;
        lastRenderedViewport.hflip = enabledElement.viewport.hflip;
        lastRenderedViewport.vflip = enabledElement.viewport.vflip;
    }

    // Module exports
    cornerstone.renderGrayscaleImage = renderGrayscaleImage;

    return cornerstone;
}(cornerstone));

/**
 * This module is responsible for drawing an image to an enabled elements canvas element
 */

var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * API function to draw a standard web image (PNG, JPG) to an enabledImage
     *
     * @param enabledElement
     * @param invalidated - true if pixel data has been invaldiated and cached rendering should not be used
     */
    function renderWebImage(enabledElement, invalidated) {

        if(enabledElement === undefined) {
            throw "drawImage: enabledElement parameter must not be undefined";
        }
        var image = enabledElement.image;
        if(image === undefined) {
            throw "drawImage: image must be loaded before it can be drawn";
        }

        // get the canvas context and reset the transform
        var context = enabledElement.canvas.getContext('2d');
        context.setTransform(1, 0, 0, 1, 0, 0);

        // clear the canvas
        context.fillStyle = 'black';
        context.fillRect(0,0, enabledElement.canvas.width, enabledElement.canvas.height);

        // turn off image smooth/interpolation if pixelReplication is set in the viewport
        if(enabledElement.viewport.pixelReplication === true) {
            context.imageSmoothingEnabled = false;
            context.mozImageSmoothingEnabled = false; // firefox doesn't support imageSmoothingEnabled yet
        }
        else {
            context.imageSmoothingEnabled = true;
            context.mozImageSmoothingEnabled = true;
        }

        // save the canvas context state and apply the viewport properties
        cornerstone.setToPixelCoordinateSystem(enabledElement, context);

        // if the viewport ww/wc and invert all match the initial state of the image, we can draw the image
        // directly.  If any of those are changed, we call renderColorImage() to apply the lut
        if(enabledElement.viewport.voi.windowWidth === enabledElement.image.windowWidth &&
            enabledElement.viewport.voi.windowCenter === enabledElement.image.windowCenter &&
            enabledElement.viewport.invert === false)
        {
            context.drawImage(image.getImage(), 0, 0, image.width, image.height, 0, 0, image.width, image.height);
        } else {
            cornerstone.renderColorImage(enabledElement, invalidated);
        }

    }

    // Module exports
    cornerstone.renderWebImage = renderWebImage;

    return cornerstone;
}(cornerstone));
/**
 * This module is responsible for enabling an element to display images with cornerstone
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    function setCanvasSize(element, canvas)
    {
        // the device pixel ratio is 1.0 for normal displays and > 1.0
        // for high DPI displays like Retina
        /*

        This functionality is disabled due to buggy behavior on systems with mixed DPI's.  If the canvas
        is created on a display with high DPI (e.g. 2.0) and then the browser window is dragged to
        a different display with a different DPI (e.g. 1.0), the canvas is not recreated so the pageToPixel
        produces incorrect results.  I couldn't find any way to determine when the DPI changed other than
        by polling which is not very clean.  If anyone has any ideas here, please let me know, but for now
        we will disable this functionality.  We may want
        to add a mechanism to optionally enable this functionality if we can determine it is safe to do
        so (e.g. iPad or iPhone or perhaps enumerate the displays on the system.  I am choosing
        to be cautious here since I would rather not have bug reports or safety issues related to this
        scenario.

        var devicePixelRatio = window.devicePixelRatio;
        if(devicePixelRatio === undefined) {
            devicePixelRatio = 1.0;
        }
        */

        canvas.width = element.clientWidth;
        canvas.height = element.clientHeight;
        canvas.style.width = element.clientWidth + "px";
        canvas.style.height = element.clientHeight + "px";
    }

    /**
     * resizes an enabled element and optionally fits the image to window
     * @param element
     * @param fitToWindow true to refit, false to leave viewport parameters as they are
     */
    function resize(element, fitToWindow) {

        var enabledElement = cornerstone.getEnabledElement(element);

        setCanvasSize(element, enabledElement.canvas);

        if(enabledElement.image === undefined ) {
            return;
        }

        if(fitToWindow === true) {
            cornerstone.fitToWindow(element);
        }
        else {
            cornerstone.updateImage(element);
        }
    }

    // module/private exports
    cornerstone.resize = resize;

    return cornerstone;
}(cornerstone));
/**
 * This module contains a function that will set the canvas context to the pixel coordinates system
 * making it easy to draw geometry on the image
 */

var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Sets the canvas context transformation matrix to the pixel coordinate system.  This allows
     * geometry to be driven using the canvas context using coordinates in the pixel coordinate system
     * @param ee
     * @param context
     * @param scale optional scaler to apply
     */
    function setToPixelCoordinateSystem(enabledElement, context, scale)
    {
        if(enabledElement === undefined) {
            throw "setToPixelCoordinateSystem: parameter enabledElement must not be undefined";
        }
        if(context === undefined) {
            throw "setToPixelCoordinateSystem: parameter context must not be undefined";
        }

        // reset the transformation matrix
        context.setTransform(1, 0, 0, 1, 0, 0);
        // move origin to center of canvas
        context.translate(enabledElement.canvas.width/2, enabledElement.canvas.height / 2);

        // apply the scale
        var widthScale = enabledElement.viewport.scale;
        var heightScale = enabledElement.viewport.scale;
        if(enabledElement.image.rowPixelSpacing < enabledElement.image.columnPixelSpacing) {
            widthScale = widthScale * (enabledElement.image.columnPixelSpacing / enabledElement.image.rowPixelSpacing);
        }
        else if(enabledElement.image.columnPixelSpacing < enabledElement.image.rowPixelSpacing) {
            heightScale = heightScale * (enabledElement.image.rowPixelSpacing / enabledElement.image.columnPixelSpacing);
        }
        context.scale(widthScale, heightScale);

        // apply the pan offset
        context.translate(enabledElement.viewport.translation.x, enabledElement.viewport.translation.y);

        if(scale === undefined) {
            scale = 1.0;
        } else {
            // apply the font scale
            context.scale(scale, scale);
        }
        
        //Apply if rotation required        
        var angle = enabledElement.viewport.rotation;

		if(angle!==0) {
			context.rotate(angle*Math.PI/180);
		}

		//Apply Flip if required
		if(enabledElement.viewport.hflip) {
			context.translate(enabledElement.offsetWidth,0);
			context.scale(-1,1);
		} 

		if(enabledElement.viewport.vflip) {
			context.translate(0, enabledElement.offsetHeight);
			context.scale(1,-1);
		}    
        
        // translate the origin back to the corner of the image so the event handlers can draw in image coordinate system
        context.translate(-enabledElement.image.width / 2 / scale, -enabledElement.image.height/ 2 / scale);
    }

    // Module exports
    cornerstone.setToPixelCoordinateSystem = setToPixelCoordinateSystem;

    return cornerstone;
}(cornerstone));

/**
 * This module contains a function to convert stored pixel values to display pixel values using a LUT
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * This function transforms stored pixel values into a canvas image data buffer
     * by using a LUT.  This is the most performance sensitive code in cornerstone and
     * we use a special trick to make this go as fast as possible.  Specifically we
     * use the alpha channel only to control the luminance rather than the red, green and
     * blue channels which makes it over 3x faster.  The canvasImageDataData buffer needs
     * to be previously filled with white pixels.
     *
     * NOTE: Attribution would be appreciated if you use this technique!
     *
     * @param pixelData the pixel data
     * @param lut the lut
     * @param canvasImageDataData a canvasImgageData.data buffer filled with white pixels
     */
    function storedPixelDataToCanvasImageData(image, lut, canvasImageDataData)
    {
        var pixelData = image.getPixelData();
        var minPixelValue = image.minPixelValue;
        var canvasImageDataIndex = 3;
        var storedPixelDataIndex = 0;
        var localNumPixels = pixelData.length;
        var localPixelData = pixelData;
        var localLut = lut;
        var localCanvasImageDataData = canvasImageDataData;
        // NOTE: As of Nov 2014, most javascript engines have lower performance when indexing negative indexes.
        // We have a special code path for this case that improves performance.  Thanks to @jpambrun for this enhancement
        if(minPixelValue < 0){
            while(storedPixelDataIndex < localNumPixels) {
                localCanvasImageDataData[canvasImageDataIndex] = localLut[localPixelData[storedPixelDataIndex++] + (-minPixelValue)]; // alpha
                canvasImageDataIndex += 4;
            }
        }else{
            while(storedPixelDataIndex < localNumPixels) {
                localCanvasImageDataData[canvasImageDataIndex] = localLut[localPixelData[storedPixelDataIndex++]]; // alpha
                canvasImageDataIndex += 4;
            }
        }
    }

    function storedColorPixelDataToCanvasImageData(image, lut, canvasImageDataData)
    {
        var minPixelValue = image.minPixelValue;
        var canvasImageDataIndex = 0;
        var storedPixelDataIndex = 0;
        var numPixels = image.width * image.height * 4;
        var storedPixelData = image.getPixelData();
        var localLut = lut;
        var localCanvasImageDataData = canvasImageDataData;
        // NOTE: As of Nov 2014, most javascript engines have lower performance when indexing negative indexes.
        // We have a special code path for this case that improves performance.  Thanks to @jpambrun for this enhancement
        if(minPixelValue < 0){
            while(storedPixelDataIndex < numPixels) {
                localCanvasImageDataData[canvasImageDataIndex++] = localLut[storedPixelData[storedPixelDataIndex++] + (-minPixelValue)]; // red
                localCanvasImageDataData[canvasImageDataIndex++] = localLut[storedPixelData[storedPixelDataIndex++] + (-minPixelValue)]; // green
                localCanvasImageDataData[canvasImageDataIndex] = localLut[storedPixelData[storedPixelDataIndex] + (-minPixelValue)]; // blue
                storedPixelDataIndex+=2;
                canvasImageDataIndex+=2;
            }
        }else{
            while(storedPixelDataIndex < numPixels) {
                localCanvasImageDataData[canvasImageDataIndex++] = localLut[storedPixelData[storedPixelDataIndex++]]; // red
                localCanvasImageDataData[canvasImageDataIndex++] = localLut[storedPixelData[storedPixelDataIndex++]]; // green
                localCanvasImageDataData[canvasImageDataIndex] = localLut[storedPixelData[storedPixelDataIndex]]; // blue
                storedPixelDataIndex+=2;
                canvasImageDataIndex+=2;
            }
        }
    }

    // Module exports
    cornerstone.storedPixelDataToCanvasImageData = storedPixelDataToCanvasImageData;
    cornerstone.storedColorPixelDataToCanvasImageData = storedColorPixelDataToCanvasImageData;

   return cornerstone;
}(cornerstone));

/**
 * This module contains a function to immediately redraw an image
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    /**
     * Forces the image to be updated/redrawn for the specified enabled element
     * @param element
     */
    function updateImage(element, invalidated) {
        var enabledElement = cornerstone.getEnabledElement(element);

        if(enabledElement.image === undefined) {
            throw "updateImage: image has not been loaded yet";
        }

        cornerstone.drawImage(enabledElement, invalidated);
    }

    // module exports
    cornerstone.updateImage = updateImage;

    return cornerstone;
}(cornerstone));
/**
 * This module contains functions to deal with getting and setting the viewport for an enabled element
 */
var cornerstone = (function (cornerstone) {

    "use strict";

    if(cornerstone === undefined) {
        cornerstone = {};
    }

    function setViewport(element, viewport) {

        var enabledElement = cornerstone.getEnabledElement(element);

        enabledElement.viewport.scale = viewport.scale;
        enabledElement.viewport.translation.x = viewport.translation.x;
        enabledElement.viewport.translation.y = viewport.translation.y;
        enabledElement.viewport.voi.windowWidth = viewport.voi.windowWidth;
        enabledElement.viewport.voi.windowCenter = viewport.voi.windowCenter;
        enabledElement.viewport.invert = viewport.invert;
        enabledElement.viewport.pixelReplication = viewport.pixelReplication;
        enabledElement.viewport.rotation = viewport.rotation;
        enabledElement.viewport.hflip = viewport.hflip;
        enabledElement.viewport.vflip = viewport.vflip;

        // prevent window width from being < 1
        if(enabledElement.viewport.voi.windowWidth < 1) {
            enabledElement.viewport.voi.windowWidth = 1;
        }
        // prevent scale from getting too small
        if(enabledElement.viewport.scale < 0.0001) {
            enabledElement.viewport.scale = 0.25;
        }

		if(enabledElement.viewport.rotation===360 || enabledElement.viewport.rotation===-360) {
			enabledElement.viewport.rotation = 0;
        }
        
        // Force the image to be updated since the viewport has been modified
        cornerstone.updateImage(element);
    }

    /**
     * Returns the viewport for the specified enabled element
     * @param element
     * @returns {*}
     */
    function getViewport(element) {
        var enabledElement = cornerstone.getEnabledElement(element);

        var viewport = enabledElement.viewport;
        if(viewport === undefined) {
            return undefined;
        }
        return {
            scale : viewport.scale,
            translation : {
                x : viewport.translation.x,
                y : viewport.translation.y
            },
            voi : {
                windowWidth: viewport.voi.windowWidth,
                windowCenter : viewport.voi.windowCenter
            },
            invert : viewport.invert,
            pixelReplication: viewport.pixelReplication,
            rotation: viewport.rotation, 
            hflip: viewport.hflip,
            vflip: viewport.vflip
        };
    }


    // module/private exports
    cornerstone.getViewport = getViewport;
    cornerstone.setViewport=setViewport;

    return cornerstone;
}(cornerstone));