Core Introduction

This section describes the core concepts in the Cornerstone3D (@cornerstonejs/core). Cornerstone3D is more than a "rendering" library. It handles:

rendering of the image (both using GPU or CPU)
caching of the data and metadata
providing a framework for image/volume loader APIs
providing metadata API support.

The purpose of this section is to give an overview of the core concepts in Cornerstone3D.

📄️ ImageId

A Cornerstone3D ImageId is a URL which identifies a single image for cornerstone to display.

📄️ Image Loaders

An ImageLoader is a JavaScript function that is responsible for taking an ImageId and returning

Cornerstone Image Loaders return Image Load Objects which contain a Promise. The reason we have chosen to use an Object instead of solely returning a Promise is because now Image Loaders can also return other properties in their Image Load Objects. As an example, we intend to implement support for cancelling pending or ongoing requests using a cancelFn passed back by an Image Loader within an Image Load Object.

📄️ Metadata Providers

For package-level architecture and current 5.x metadata behavior, see

📄️ Volumes

A volume is a 3D data array that has a physical size and orientation in space. It can be built by composing pixel data and metadata of a 3D imaging series, or can be defined from scratch by the application. A volume has a FrameOfReferenceUID, voxelSpacing (x,y,z), voxel dimensions (x,y,z), origin, and orientation vectors which uniquely define its coordinate system with respect to the patient coordinate system.

📄️ Voxel Manager

The VoxelManager is a key component of the Cornerstone library’s new architecture for handling voxel data and volume management. This updated design streamlines data flow and enhances performance, providing a single source of truth for image caching and data access, with a focus on reducing memory usage and improving performance in handling large image datasets.

📄️ Volume Loaders

Similar to the Image Loaders, a volume loader takes a volumeId and other information

📄️ Geometry Loaders

This section describes the geometry loaders in Cornerstone Core.

📄️ Cache

The Cache API’s role is to keep track of created volumes, manage memory usage, and alert the host application when trying to allocate data that would exceed application defined limits.

📄️ Viewports

A viewport can be thought of as:

🗃️ Generic Viewport

6 items

📄️ Rendering Engine

A RenderingEngine allows the user to create Viewports, associate these Viewports with onscreen HTML elements, and render data to these elements using an offscreen WebGL canvas.

📄️ Request Pool Manager

The RequestPool Manager has been extensively reworked to provide two new features: 1) asynchronous image retrieval and decoding 2) requests re-ordering.

📄️ Web Workers

WebWorkers provide a way to run scripts in background threads, allowing web applications to perform tasks without interfering with the user interface. They are particularly useful for executing computationally intensive tasks or those that require a lot of processing time.