Cornerstone

# Cornerstone core API

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# Table of Contents

# Objects

# vec2

A two-dimensional vector

Type: Object (opens new window)

# Parameters

# VOI

VOI

Type: Object (opens new window)

# Parameters

# LUT

Lookup Table Array

Type: Object (opens new window)

# Properties

# ImageStats

Image Statistics Object

Type: Object (opens new window)

# Properties

# Image

An Image Object in Cornerstone

Type: Object (opens new window)

# Properties

# Viewport

A Viewport Settings Object Cornerstone

Type: Object (opens new window)

# Properties

  • scale Number (opens new window)? The scale applied to the image. A scale of 1.0 will display no zoom (one image pixel takes up one screen pixel). A scale of 2.0 will be double zoom and a scale of .5 will be zoomed out by 2x
  • translation vec2? An object with properties x and y which describe the translation to apply in the pixel coordinate system. Note that the image is initially displayed centered in the enabled element with a x and y translation of 0 and 0 respectively.
  • voi VOI? an object with properties windowWidth and windowCenter.
  • invert boolean (opens new window)? Whether or not the image is inverted.
  • pixelReplication boolean (opens new window)? true if the image smooth / interpolation should be used when zoomed in on the image or false if pixel replication should be used.
  • hflip boolean (opens new window)? true if the image is flipped horizontally. Default is false
  • vflip boolean (opens new window)? true if the image is flipped vertically. Default is false
  • rotation Number (opens new window)? the rotation of the image (90 degree increments). Default is 0
  • modalityLUT LUT? the modality LUT to apply or undefined if none
  • voiLUT LUT? the modality LUT to apply or undefined if none
  • colormap (String (opens new window) | Colormap)? an optional colormap ID or colormap object (from colors/colormap.js). This will be applied during rendering to convert the image to pseudocolor
  • labelmap Boolean (opens new window)? whether or not to render this image as a label map (i.e. skip modality and VOI LUT pipelines and use only a color lookup table)

# EnabledElement

An Enabled Element in Cornerstone

Type: Object (opens new window)

# Properties

# EnabledElementLayer

An Enabled Element Layer in Cornerstone

Type: Object (opens new window)

# Properties

# ImageLoadObject

An Image Load Object

Type: Object (opens new window)

# Properties

# VOILUTFunction

Volume of Interest Lookup Table Function

Type: Function (opens new window)

# Parameters

Returns Number (opens new window) transformed value

# EnabledElements

# getEnabledElement

Retrieves a Cornerstone Enabled Element object

# Parameters

Returns EnabledElement A Cornerstone Enabled Element

# addEnabledElement

Adds a Cornerstone Enabled Element object to the central store of enabledElements

# Parameters

  • enabledElement EnabledElement A Cornerstone enabledElement Object

Returns void

# getEnabledElementsByImageId

Adds a Cornerstone Enabled Element object to the central store of enabledElements

# Parameters

Returns Array (opens new window)<EnabledElement> An Array of Cornerstone enabledElement Objects

# getEnabledElements

Retrieve all of the currently enabled Cornerstone elements

Returns Array (opens new window)<EnabledElement> An Array of Cornerstone enabledElement Objects

# ImageLoader

This module deals with ImageLoaders, loading images and caching images

# loadImageFromImageLoader

Load an image using a registered Cornerstone Image Loader.

The image loader that is used will be determined by the image loader scheme matching against the imageId.

# Parameters

Returns ImageLoadObject An Object which can be used to act after an image is loaded or loading fails

# loadImage

Loads an image given an imageId and optional priority 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.

# Parameters

Returns ImageLoadObject An Object which can be used to act after an image is loaded or loading fails

# loadAndCacheImage

Loads an image given an imageId and optional priority 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.

# Parameters

Returns ImageLoadObject Image Loader Object

# registerImageLoader

Registers an imageLoader plugin with cornerstone for the specified scheme

# Parameters

Returns void

# registerUnknownImageLoader

Registers a new unknownImageLoader and returns the previous one

# Parameters

Returns (Function (opens new window) | Undefined (opens new window)) The previous Unknown Image Loader

# ImageCache

This module deals with caching images

# Metadata

# addProvider

Adds a metadata provider with the specified priority

# Parameters

Returns void

# removeProvider

Removes the specified provider

# Parameters

Returns void

# getMetaData

Gets metadata from the registered metadata providers. Will call each one from highest priority to lowest until one responds

# Parameters

Returns any The metadata retrieved from the metadata store

# EnabledElementLayers

# triggerEventForLayer

Helper function to trigger an event on a Cornerstone element with a specific layerId

# Parameters

Returns void

# rescaleImage

Rescale the target layer to the base layer based on the relative size of each image and their pixel dimensions.

This function will update the Viewport parameters of the target layer to a new scale.

# Parameters

  • baseLayer EnabledElementLayer The base layer
  • targetLayer EnabledElementLayer The target layer to rescale

Returns void

# addLayer

Add a layer to a Cornerstone element

# Parameters

Returns String (opens new window) layerId The new layer's unique identifier

# removeLayer

Remove a layer from a Cornerstone element given a layer ID

# Parameters

Returns void

# getLayer

Retrieve a layer from a Cornerstone element given a layer ID

# Parameters

Returns EnabledElementLayer The layer

# getLayers

Retrieve all layers for a Cornerstone element

# Parameters

Returns Array (opens new window)<EnabledElementLayer> An array of layers

# getVisibleLayers

Retrieve all visible layers for a Cornerstone element

# Parameters

Returns Array (opens new window)<EnabledElementLayer> An array of layers

# setActiveLayer

Set the active layer for a Cornerstone element

# Parameters

Returns void

# setLayerImage

Set a new image for a specific layerId

# Parameters

Returns void

# getActiveLayer

Retrieve the currently active layer for a Cornerstone element

# Parameters

Returns EnabledElementLayer The currently active layer

# Internal

# guid

Generate a unique identifier

Returns string (opens new window) A unique identifier

# drawImage

Internal API function to draw an image to a given enabled element

# Parameters

  • enabledElement EnabledElement The Cornerstone Enabled Element to redraw
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used (optional, default false)

Returns void

# drawImageSync

Draw an image to a given enabled element synchronously

# Parameters

  • enabledElement EnabledElement An enabled element to draw into
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used

Returns void

# renderLayers

Internal function to render all layers for a Cornerstone enabled element

# Parameters

Returns void

# getImageFitScale

Calculates the horizontal, vertical and minimum scale factor for an image

# Parameters

  • windowSize {width, height} The window size where the image is displayed. This can be any HTML element or structure with a width, height fields (e.g. canvas).
  • image any The cornerstone image object
  • rotation Number (opens new window) Optional. The rotation angle of the image. (optional, default null)

Returns {horizontalScale, verticalScale, scaleFactor} The calculated horizontal, vertical and minimum scale factor

# generateLut

Creates a LUT used while rendering to convert stored pixel values to display pixels

# Parameters

Returns Uint8ClampedArray (opens new window) A lookup table to apply to the image

# getDefaultViewport

Creates a new viewport object containing default values for the image and canvas

# Parameters

Returns Viewport viewport object

# createDefaultDisplayedArea

Creates the default displayed area. C.10.4 Displayed Area Module: This Module describes Attributes required to define a Specified Displayed Area space.

# createViewport

Creates a new viewport object containing default values

Returns Viewport viewport object

# generateLinearModalityLUT

Generates a linear modality transformation function

See DICOM PS3.3 C.11.1 Modality LUT Module

http://dicom.nema.org/medical/Dicom/current/output/chtml/part03/sect_C.11.html (opens new window)

# Parameters

  • slope Number (opens new window) m in the equation specified by Rescale Intercept (0028,1052).
  • intercept Number (opens new window) The value b in relationship between stored values (SV) and the output units specified in Rescale Type (0028,1054).Output units = m*SV + b.

Returns function (any): any A linear modality LUT function. Given a stored pixel it returns the modality pixel value

# getModalityLUT

Get the appropriate Modality LUT for the current situation.

# Parameters

Returns function (any): any A modality LUT function. Given a stored pixel it returns the modality pixel value.

# storedPixelDataToCanvasImageDataRGBA

This function transforms stored pixel values into a canvas image data buffer by using a LUT.

# Parameters

Returns void

# generateColorLut

Creates a LUT used while rendering to convert stored pixel values to display pixels

# Parameters

Returns Uint8ClampedArray (opens new window) A lookup table to apply to the image

# storedRGBAPixelDataToCanvasImageData

Converts stored RGBA color pixel values to display pixel values using a LUT.

# Parameters

Returns void

# computeAutoVoi

Computes the VOI to display all the pixels if no VOI LUT data (Window Width/Window Center or voiLUT) exists on the viewport object.

# Parameters

  • viewport Viewport Object containing the viewport properties
  • image Object (opens new window) An Image loaded by a Cornerstone Image Loader

Returns void

# hasVoi

Check if viewport has voi LUT data

# Parameters

  • viewport any The viewport to check for voi LUT data

Returns Boolean (opens new window) true viewport has LUT data (Window Width/Window Center or voiLUT). Otherwise, false.

# isRotated

Check if the angle is rotated

# Parameters

Returns Boolean (opens new window) true if the angle is rotated; Otherwise, false.

# getImageSize

Retrieves the current image dimensions given an enabled element

# Parameters

  • image any The Cornerstone image.
  • rotation Number (opens new window) Optional. The rotation angle of the image. (optional, default null)

Returns {width: Number (opens new window), height: Number (opens new window)} The Image dimensions

# calculateTransform

Calculate the transform for a Cornerstone enabled element

# Parameters

Returns Transform The current transform

# storedColorPixelDataToCanvasImageData

Converts stored color pixel values to display pixel values using a LUT.

Note: Skips alpha value for any input image pixel data.

# Parameters

Returns void

# storedPixelDataToCanvasImageData

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!

# Parameters

Returns void

# storedPixelDataToCanvasImageDataColorLUT

# Parameters

Returns void

# storedPixelDataToCanvasImageDataPseudocolorLUT

# Parameters

Returns void

# rendering

# getLut

Generates an appropriate Look Up Table to render the given image with the given window width and level (specified in the viewport) Uses an internal cache for performance

# Parameters

Returns Uint8ClampedArray (opens new window) Look Up Table array.

# getLut

Retrieve or generate a LUT Array for an Image and Viewport

# Parameters

  • image Image (opens new window) An Image Object
  • viewport Viewport An Viewport Object
  • invalidated Boolean (opens new window) Whether or not the LUT data has been invalidated (e.g. by a change to the windowWidth, windowCenter, or invert viewport parameters).

Returns Uint8ClampedArray (opens new window) LUT Array

# getRenderCanvas

Returns an appropriate canvas to render the Image. If the canvas available in the cache is appropriate it is returned, otherwise adjustments are made. It also sets the color transfer functions.

# Parameters

Returns HTMLCanvasElement (opens new window) An appropriate canvas for rendering the image

# getRenderCanvas

Returns an appropriate canvas to render the Image. If the canvas available in the cache is appropriate it is returned, otherwise adjustments are made. It also sets the color transfer functions.

# Parameters

Returns HTMLCanvasElement (opens new window) An appropriate canvas for rendering the image

# getRenderCanvas

Returns an appropriate canvas to render the Image. If the canvas available in the cache is appropriate it is returned, otherwise adjustments are made. It also sets the color transfer functions.

# Parameters

Returns HTMLCanvasElement (opens new window) An appropriate canvas for rendering the image

# getRenderCanvas

Returns an appropriate canvas to render the Image. If the canvas available in the cache is appropriate it is returned, otherwise adjustments are made. It also sets the color transfer functions.

# Parameters

Returns HTMLCanvasElement (opens new window) An appropriate canvas for rendering the image

# renderColorImage

API function to render a color image to an enabled element

# Parameters

  • enabledElement EnabledElement The Cornerstone Enabled Element to redraw
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used

Returns void

# doesImageNeedToBeRendered

Determine whether or not an Enabled Element needs to be re-rendered.

If the imageId has changed, or if any of the last rendered viewport parameters have changed, this function will return true.

# Parameters

Returns boolean (opens new window) Whether or not the Enabled Element needs to re-render its image

# initializeRenderCanvas

Sets size and clears canvas

# Parameters

Returns void

# saveLastRendered

Saves the parameters of the last render into renderingTools, used later to decide if data can be reused.

# Parameters

Returns Object (opens new window) enabledElement.renderingTools

# renderGrayscaleImage

API function to draw a grayscale image to a given enabledElement

# Parameters

  • enabledElement EnabledElement The Cornerstone Enabled Element to redraw
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used

Returns void

# lutMatches

Check if two lookup tables match

# Parameters

  • a LUT A lookup table function
  • b LUT Another lookup table function

Returns boolean (opens new window) Whether or not they match

# renderLabelMapImage

API function to draw a label map image to a given enabledElement

# Parameters

  • enabledElement EnabledElement The Cornerstone Enabled Element to redraw
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used

Returns void

# renderPseudoColorImage

API function to draw a pseudo-color image to a given enabledElement

# Parameters

  • enabledElement EnabledElement The Cornerstone Enabled Element to redraw
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used

Returns void

# EnabledElementStub

Type: Object (opens new window)

# Properties

# createEnabledElementStub

creates a dummy enabled element

# Parameters

  • canvas HTMLCanvasElement (opens new window) the canvas that will be assigned to the enabled element.
  • image any An Image loaded by a Cornerstone Image Loader
  • options any Options for rendering the image (e.g.enable webgl by {renderer: 'webgl' })
  • viewport any A set of Cornerstone viewport parameters

Returns EnabledElementStub a dummy enabled element

# renderToCanvas

Render the image to the provided canvas immediately.

# Parameters

  • canvas any The HTML canvas where the image will be rendered.
  • image any An Image loaded by a Cornerstone Image Loader
  • viewport any A set of Cornerstone viewport parameters (optional, default null)
  • options any Options for rendering the image (e.g. enable webgl by {renderer: 'webgl'}) (optional, default null)

Returns void

# renderWebImage

API function to draw a standard web image (PNG, JPG) to an enabledImage

# Parameters

  • enabledElement EnabledElement The Cornerstone Enabled Element to redraw
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used

Returns void

# WebGLRendering

# getImageDataType

Returns the image data type as a string representation.

# Parameters

  • image any The cornerstone image object

Returns string (opens new window) image data type (rgb, iint16, uint16, int8 and uint8)

# storedPixelDataToImageData

Convert stored pixel data to image data.

Pack int16 into three uint8 channels (r, g, b)

# Parameters

Returns Uint8Array (opens new window) The image data for use by the WebGL shader

# storedPixelDataToImageData

Convert stored pixel data to image data.

Store data in Uint8Array

# Parameters

Returns Uint8Array (opens new window) The image data for use by the WebGL shader

# storedPixelDataToImageData

Convert stored pixel data to image data.

Pack RGB images into a 3-channel RGB texture

# Parameters

Returns Uint8Array (opens new window) The image data for use by the WebGL shader

# storedPixelDataToImageData

Convert stored pixel data to image data.

For uint16 pack uint16 into two uint8 channels (r and a).

# Parameters

Returns Uint8Array (opens new window) The image data for use by the WebGL shader

# storedPixelDataToImageData

Convert stored pixel data to image data. Here we will store all data in the alpha channel.

# Parameters

Returns Uint8Array (opens new window) The image data for use by the WebGL shader

# compileShader

Creates and compiles a shader.

# Parameters

Returns WebGLShader The shader.

# createProgram

Creates a program from 2 shaders.

# Parameters

  • gl WebGLRenderingContext The WebGL context.
  • vertexShader WebGLShader A vertex shader.
  • fragmentShader WebGLShader A fragment shader.

Returns WebGLProgram A program.

# createProgramFromString

Creates a program from 2 shaders source (Strings)

# Parameters

  • gl WebGLRenderingContext The WebGL context.
  • vertexShaderSrc WebGLShader Vertex shader string
  • fragShaderSrc WebGLShader Fragment shader string

Returns WebGLProgram A program

# Polyfills

# EventTarget

EventTarget - Provides the EventTarget (opens new window) interface

# now

Use the performance.now() method if possible, and if not, use Date.now()

Returns number (opens new window) Time elapsed since the time origin

# requestAnimationFrame

Polyfills requestAnimationFrame for older browsers.

# Parameters

  • callback Function (opens new window) A parameter specifying a function to call when it's time to update your animation for the next repaint. The callback has one single argument, a DOMHighResTimeStamp, which indicates the current time (the time returned from performance.now() ) for when requestAnimationFrame starts to fire callbacks.

Returns Number (opens new window) A long integer value, the request id, that uniquely identifies the entry in the callback list. This is a non-zero value, but you may not make any other assumptions about its value. You can pass this value to window.cancelAnimationFrame() to cancel the refresh callback request.

# purgeLayers

Purge the layers

# Parameters

Returns void

# getPixelValues

Retrieves the minimum and maximum pixel values from an Array of pixel data

# Parameters

Returns {minPixelValue: Number (opens new window), maxPixelValue: Number (opens new window)} The minimum and maximum pixel values in the input Array

# getRestoreImageMethod

Retrieve a function that will allow an image object to be reset to its original form after a false color mapping transformation

# Parameters

Returns Function (opens new window) A function for resetting an Image Object to its original form

# ensuresColormap

User can pass a colormap or its id as string to some of these public functions. Then we need to make sure it will be converted into a colormap object if it's a string.

# Parameters

  • colormap any A colormap ID or Object

Returns any The colormap

# restoreImage

Restores a false color image to its original version

# Parameters

Returns Boolean (opens new window) True if the image object had a valid restore function, which was run. Otherwise, false.

# convertImageToFalseColorImage

Convert an image to a false color image

# Parameters

Returns Boolean (opens new window) Whether or not the image has been converted to a false color image

# convertToFalseColorImage

Convert the image of a element to a false color image

# Parameters

Returns void

# linspace

Generate linearly spaced vectors http://cens.ioc.ee/local/man/matlab/techdoc/ref/linspace.html (opens new window)

# Parameters

Returns Array (opens new window) An array of points representing linear spaced vectors.

# getRank

Returns the "rank/index" of the element in a sorted array if found or the highest index if not. Uses (binary search)

# Parameters

Returns number (opens new window) The rank/index of the element in the given array

# searchSorted

Find the indices into a sorted array a such that, if the corresponding elements In v were inserted before the indices, the order of a would be preserved. http://lagrange.univ-lyon1.fr/docs/numpy/1.11.0/reference/generated/numpy.searchsorted.html (opens new window)

# Parameters

Returns Array (opens new window) The indices where elements should be inserted to maintain order.

# makeMappingArray

Creates an N -element 1-d lookup table

# Parameters

  • N Number (opens new window) The number of elements in the result lookup table
  • data Array (opens new window) represented by a list of x,y0,y1 mapping correspondences. Each element in this List represents how a value between 0 and 1 (inclusive) represented by x is mapped to A corresponding value between 0 and 1 (inclusive). The two values of y are to allow for Discontinuous mapping functions (say as might be found in a sawtooth) where y0 represents The value of y for values of x <= to that given, and y1 is the value to be used for x > Than that given). The list must start with x=0, end with x=1, and all values of x must be In increasing order. Values between the given mapping points are determined by simple linear Interpolation.
  • gamma any value denotes a "gamma curve" value which adjusts the brightness at the bottom and top of the map.

Returns Array (opens new window)<any> an array "result" where result[x*(N-1)] gives the closest value for Values of x between 0 and 1.

# createLinearSegmentedColormap

The lookup table is generated using linear interpolation for each Primary color, with the 0-1 domain divided into any number of Segments. https://github.com/stefanv/matplotlib/blob/3f1a23755e86fef97d51e30e106195f34425c9e3/lib/matplotlib/colors.py#L663 (opens new window)

# Parameters

Returns Array (opens new window) The created Colormap object

# getColormapsList

Return all available colormaps (id and name)

Returns Array (opens new window)<{id, key}> An array of colormaps with an object containing the "id" and display "name"

# getColormap

Return a colorMap object with the provided id and colormapData if the Id matches existent colorMap objects (check colormapsData) the colormapData is ignored. if the colormapData is not empty, the colorMap will be added to the colormapsData list. Otherwise, an empty colorMap object is returned.

# Parameters

Returns any The Colormap Object

# linearIndexLookupMain

Maps a value to an index in the table

# Parameters

  • v Number (opens new window) A double value which table index will be returned.
  • p any An object that contains the Table "Range", the table "MaxIndex", A "Shift" from first value in the table and the table "Scale" value

Returns Number (opens new window) The mapped index in the table

# setNumberOfTableValues

Specify the number of values (i.e., colors) in the lookup table.

# Parameters

Returns void

# setRamp

Set the shape of the table ramp to either 'linear', 'scurve' or 'sqrt'

# Parameters

  • ramp String (opens new window) A string value representing the shape of the table. Allowed values are 'linear', 'scurve' or 'sqrt'

Returns void

# setTableRange

Sets the minimum/maximum scalar values for scalar mapping. Scalar values less than minimum range value are clamped to minimum range value. Scalar values greater than maximum range value are clamped to maximum range value.

# Parameters

  • start Number (opens new window) A double representing the minimum scaler value of the LookupTable
  • end any A double representing the maximum scaler value of the LookupTable

Returns void

# setHueRange

Set the range in hue (using automatic generation). Hue ranges between [0,1].

# Parameters

Returns void

# setSaturationRange

Set the range in saturation (using automatic generation). Saturation ranges between [0,1].

# Parameters

Returns void

# setValueRange

Set the range in value (using automatic generation). Value ranges between [0,1].

# Parameters

  • start Numeber A double representing the minimum value in a range. Min. is 0
  • end Numeber A double representing the maximum value in a range. Max. is 1

Returns void

# setRange

(Not Used) Sets the range of scalars which will be mapped.

# Parameters

Returns void

# setAlphaRange

Set the range in alpha (using automatic generation). Alpha ranges from [0,1].

# Parameters

Returns void

# getColor

Map one value through the lookup table and return the color as an RGBA array of doubles between 0 and 1.

# Parameters

Returns Array (opens new window)<Number (opens new window)> An RGBA array of doubles between 0 and 1

# build

Generate lookup table from hue, saturation, value, alpha min/max values. Table is built from linear ramp of each value.

# Parameters

  • force Boolean (opens new window) true to force the build of the LookupTable. Otherwie, false. This is useful if a lookup table has been defined manually (using SetTableValue) and then an application decides to rebuild the lookup table using the implicit process.

Returns void

# buildSpecialColors

Ensures the out-of-range colors (Below range and Above range) are set correctly.

Returns void

# mapValue

Similar to GetColor - Map one value through the lookup table and return the color as an RGBA array of doubles between 0 and 1.

# Parameters

  • v Numeber A double scalar value which will be mapped to a color in the LookupTable

Returns Array (opens new window)<Number (opens new window)> An RGBA array of doubles between 0 and 1

# getIndex

Return the table index associated with a particular value.

# Parameters

Returns Number (opens new window) The index in the LookupTable

# setTableValue

Directly load color into lookup table. Use [0,1] double values for color component specification. Make sure that you've either used the Build() method or used SetNumberOfTableValues() prior to using this method.

# Parameters

Returns void

# getElementData

Retrieves any data for a Cornerstone enabledElement for a specific string dataType

# Parameters

Returns any Whatever data is stored for this enabled element

# removeElementData

Clears any data for a Cornerstone enabledElement for a specific string dataType

# Parameters

Returns void

# canvasToPixel

Converts a point in the canvas coordinate system to the pixel coordinate system system. This can be used to reset tools' image coordinates after modifications have been made in canvas space (e.g. moving a tool by a few cm, independent of image resolution).

# Parameters

Returns {x: Number (opens new window), y: Number (opens new window)} The transformed point in the pixel coordinate system

# pixelToCanvas

Converts a point in the pixel coordinate system to the canvas coordinate system system. This can be used to render using canvas context without having the weird side effects that come from scaling and non square pixels

# Parameters

Returns {x: Number (opens new window), y: Number (opens new window)} The input point in the canvas coordinate system

# HSVToRGB

Converts an HSV (Hue, Saturation, Value) color to RGB (Red, Green, Blue) color value

# Parameters

  • hue Number (opens new window) A number representing the hue color value
  • sat any A number representing the saturation color value
  • val any A number representing the value color value

Returns Array (opens new window)<Numberp> An RGB color array

# LookupTable

Maps scalar values into colors via a lookup table LookupTable is an object that is used by mapper objects to map scalar values into rgba (red-green-blue-alpha transparency) color specification, or rgba into scalar values. The color table can be created by direct insertion of color values, or by specifying hue, saturation, value, and alpha range and generating a table

# disable

Disable an HTML element for further use in Cornerstone

# Parameters

Returns void

# hasImageOrLayers

Returns whether or not an Enabled Element has either a currently active image or a non-empty Array of Enabled Element Layers.

# Parameters

  • enabledElement EnabledElement An Enabled Element

Returns Boolean (opens new window) Whether or not the Enabled Element has an active image or valid set of layers

# enable

Enable an HTML Element for use in Cornerstone

  • If there is a Canvas already present within the HTMLElement, and it has the class 'cornerstone-canvas', this function will use this existing Canvas instead of creating a new one. This may be helpful when using libraries (e.g. React, Vue) which don't want third parties to change the DOM.

# Parameters

Returns void

# displayImage

Sets a new image object for a given element.

Will also apply an optional viewport setting.

# Parameters

Returns void

# draw

Immediately draws the enabled element

# Parameters

Returns void

# draw

Draw the image immediately

# Parameters

  • timestamp DOMHighResTimeStamp The current time for when requestAnimationFrame starts to fire callbacks

Returns void

# drawInvalidated

Draws all invalidated enabled elements and clears the invalid flag after drawing it

Returns void

# invalidate

Sets the invalid flag on the enabled element and fires an event

# Parameters

Returns void

# invalidateImageId

Forces the image to be updated/redrawn for all enabled elements displaying the specified imageId

# Parameters

Returns void

# updateImage

Forces the image to be updated/redrawn for the specified enabled element

# Parameters

Returns void

# getEnabledElements

This module is responsible for drawing invalidated enabled elements

# hasImageOrLayers

# Parameters

  • enabledElement

# drawCompositeImage

Internal API function to draw a composite image to a given enabled element

# Parameters

  • enabledElement EnabledElement An enabled element to draw into
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used

Returns void

# tryEnableWebgl

Checks if webGL is supported and initializes the rendering engine.

# Parameters

  • options any Options to check if webgl rendering is requested (e.g. enable webgl by passing {renderer: 'webgl'})

Returns Boolean (opens new window) true if webgl rendering has been successfully initialized. Otherwise, false.

# generateUUID

Generates a UUID for the enabledElement.

Returns String (opens new window) the UUID.

# createCanvas

Create a canvas and append it to the element

# Parameters

Returns HTMLElement (opens new window) canvas A Canvas DOM element

# getCanvas

Create a canvas or returns the one that already exists for a given element

# Parameters

Returns HTMLElement (opens new window) canvas A Canvas DOM element

# fitToWindow

Adjusts an image's scale and translation so the image is centered and all pixels in the image are viewable.

# Parameters

Returns void

# validateParameterUndefined

Check if the supplied parameter is undefined and throws and error

# Parameters

  • checkParam any the parameter to validate for undefined
  • errorMsg any the error message to be thrown

Returns void

# validateParameterUndefinedOrNull

Check if the supplied parameter is undefined or null and throws and error

# Parameters

  • checkParam any the parameter to validate for undefined
  • errorMsg any the error message to be thrown

Returns void

# generateLinearVOILUT

# Parameters

  • windowWidth
  • windowCenter

# generateLinearVOILUT

# Parameters

Returns VOILUTFunction VOI LUT mapping function

# generateNonLinearVOILUT

Generate a non-linear volume of interest lookup table

# Parameters

  • voiLUT LUT Volume of Interest Lookup Table Object

Returns VOILUTFunction VOI LUT mapping function

# getVOILut

Retrieve a VOI LUT mapping function given the current windowing settings and the VOI LUT for the image

# Parameters

Returns VOILUTFunction VOI LUT mapping function

# getDefaultViewportForImage

Returns a default viewport for display the specified image on the specified enabled element. The default viewport is fit to window

# Parameters

Returns Viewport The default viewport for the image

# getImage

Returns the currently displayed image for an element or undefined if no image has been displayed yet

# Parameters

Returns Image (opens new window) The Cornerstone Image Object displayed in this element

# getPixels

Retrieves an array of pixels from a rectangular region with modality LUT transformation applied

# Parameters

Returns Array (opens new window) The modality pixel value of the pixels in the sampling rectangle

# getStoredPixels

Retrieves an array of stored pixel values from a rectangular region of an image

# Parameters

Returns Array (opens new window) The stored pixel value of the pixels in the sampling rectangle

# getViewport

Retrieves the viewport for the specified enabled element

# Parameters

Returns (Viewport | undefined (opens new window)) The Cornerstone Viewport settings for this element, if they exist. Otherwise, undefined

# setViewport

Sets/updates viewport of a given enabled element

# Parameters

Returns void

# setMaximumSizeBytes

Sets the maximum size of cache and purges cache contents if necessary.

# Parameters

Returns void

# purgeCacheIfNecessary

Purges the cache if size exceeds maximum

Returns void

# putImageLoadObject

Puts a new image loader into the cache

# Parameters

Returns void

# getImageLoadObject

Retuns the object that is loading a given imageId

# Parameters

Returns void

# removeImageLoadObject

Removes the image loader associated with a given Id from the cache

# Parameters

Returns void

# CacheInformation

Type: Object (opens new window)

# Properties

Returns void

# getCacheInfo

Gets the current state of the cache

Returns void

# decache

INTERNAL: Removes and ImageLoader from the cache

# Parameters

Returns void

# purgeCache

Removes all images from cache

Returns void

# changeImageIdCacheSize

Updates the space than an image is using in the cache

# Parameters

Returns void

# pageToPixel

Converts a point in the page coordinate system to the pixel coordinate system

# Parameters

Returns {x: Number (opens new window), y: Number (opens new window)} The transformed point in the pixel coordinate system

# pixelDataToFalseColorData

Converts the image pixel data into a false color data

# Parameters

Returns void

Meta

  • deprecated: This function is superseded by the ability to set the Viewport parameters to include colormaps.

# addGrayscaleLayer

API function to draw a grayscale image to a given layer

# Parameters

  • layer EnabledElementLayer The layer that the image will be added to
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used
  • useAlphaChannel Boolean (opens new window)? Whether or not to render the grayscale image using only the alpha channel. This does not work if this layer is not the first layer in the enabledElement. (optional, default false)

Returns void

# addLabelMapLayer

API function to draw a pseudo-color image to a given layer

# Parameters

  • layer EnabledElementLayer The layer that the image will be added to
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used

Returns void

# addPseudoColorLayer

API function to draw a pseudo-color image to a given layer

# Parameters

  • layer EnabledElementLayer The layer that the image will be added to
  • invalidated Boolean (opens new window) true if pixel data has been invalidated and cached rendering should not be used

Returns void

# reset

Resets the viewport to the default settings

# Parameters

Returns void

# setCanvasSize

This module is responsible for enabling an element to display images with cornerstone

# Parameters

Returns void

# wasFitToWindow

Checks if the image of a given enabled element fitted the window before the resize

# Parameters

Returns Boolean (opens new window) true if it fitted the windows, false otherwise

# relativeRescale

Rescale the image relative to the changed size of the canvas

# Parameters

Returns void

# resize

Resizes an enabled element and optionally fits the image to window

# Parameters

Returns void

# setDefaultViewport

Sets new default values for getDefaultViewport

# Parameters

Returns undefined (opens new window)

# setToPixelCoordinateSystem

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

# Parameters

Returns void

# triggerEvent

Trigger a CustomEvent

# Parameters

Returns Boolean (opens new window) The return value is false if at least one event listener called preventDefault(). Otherwise it returns true.

# WebGLTextureCache

This module deals with caching image textures in VRAM for WebGL