Introduction to Holoscan SDK
What Is Holoscan SDK?
NVIDIA Holoscan SDK (HSDK) is the software toolkit for building applications that process live sensor data and run AI at the edge. Developers use Python or C++ to connect data capture, processing, inference and visualization into an application. For example, an application can receive camera frames, prepare them for an AI model, detect objects and display the results.
Within the Holoscan platform, the SDK provides the programming model and runtime that coordinate this work. Developers can combine ready-made components with their own algorithms and use NVIDIA GPU acceleration where their processing needs it.
How the Concepts Fit Together
Start with the work your application needs to do. Each processing step is an operator. Connect its inputs and outputs to other operators to form a graph. Reusable operators can come from modules, or you can write your own.
The solid arrows show data moving between operators. The dashed arrow shows where reusable operators come from. The processing steps are illustrative; a graph can also branch or combine multiple inputs.
The Main Building Blocks
| Concept | What it means | Example |
|---|---|---|
| Operator | A unit of work with defined inputs, outputs and processing logic. | Capture a frame, resize an image or run an AI model. |
| Port | A named input or output on an operator, with a defined data type. | An image output connected to the next operator's image input. |
| Sample and data flow | A sample is a piece of data, such as a frame or measurement, with associated metadata. Connections carry samples between compatible ports. | A camera frame travels from capture to image preparation. |
| Graph | The description of the operators, their connections and the application's timing choices. | Capture → prepare → infer → display. |
| Module | A reusable software package providing a capability through operators and supporting code. Operators from different modules can be used in the same graph. | Camera, image processing, inference and visualization modules. |
Modules package reusable capabilities; graphs connect the operators used by an application. For example, you can take a camera operator from one module, an inference operator from another, and insert your own processing operator between them. A module is not an extra processing stage that every data sample passes through.
From a Graph to a Running Application
In HSDK, an application follows three stages:
- Compose: choose operators, connect their ports and describe timing. An operator's contract specifies when it runs, which input samples it uses and how missing data is handled.
- Compile: the SDK checks the graph and produces an execution plan with validation results and execution decisions. Inspect the plan before starting the application.
- Run: the runtime executes the accepted plan. An asynchronous run returns a run session used to control and observe that execution, including requesting a stop and waiting for completion.
Continue with the Full SDK Guide
For setup, development tutorials and detailed concepts, continue to the RidgeRun Holoscan SDK wiki. The SDK at a Glance page provides a starting point for choosing a learning path.
Official references: NVIDIA SDK overview · Holoscan Modules · SDK core concepts.