Image Streamer

Table of Contents

• Creating an Image
• Initializing the ImageStreamer Module
• Streaming the Image
• Returning the Images
• Releasing the Handle

This tutorial demonstrates how to stream an image from host (CPU) memory, to device (CUDA) memory.

The ImageStreamer module is accessed through a handle:

dwImageStreamerHandle_t streamerCPU2CUDA = DW_NULL_HANDLE;

Creating an Image

To create an image for streaming:

// the image is going to be format interleaved RGB and type UINT_8
dwImageProperties cpuProp{};
cpuProp.type = DW_IMAGE_CPU;
cpuProp.width = imageWidth;
cpuProp.height = imageHeight;
cpuProp.format = DW_IMAGE_FORMAT_RGB_UINT8;
cpuProp.memoryLayout = DW_IMAGE_MEMORY_TYPE_DEFAULT; // not necessary to specify if init with {}
 
//Create an image with these properties
dwImageHandle_t rgbCPU;
dwImage_create(&rgbCPU, cpuProp, m_context);

Initializing the ImageStreamer Module

Once an image is creating for streaming, an ImageStreamer must be initialized to stream the CPU image to CUDA.
In the following example, the dwImageStreamerHandle_t handle initializes the ImageCapture module to stream
an image with cpuProp image properties to type dwImageCUDA:

// streamer from CPU to CUDA
dwImageStreamerHandle_t streamerCPU2CUDA = DW_NULL_HANDLE;
 
dwImageStreamer_initialize(streamerCPU2CUDA, &cpuProp, DW_IMAGE_CUDA, dwContext);

Streaming the Image

To stream the image:

dwImageStreamer_producerSend(rgbCPU,streamerCPU2CUDA);
dwImageHandle_t rgbCUDA;
dwImageStreamer_consumerReceive(&rgbCUDA,streamerCPU2CUDA);

Returning the Images

An image must be returned once streaming to CUDA memory is complete:

dwImageStreamer_consumerReturn(rgbCUDA,streamerCPU2CUDA);
dwImageStreamer_producerReturn(rgbCPU,streamerCPU2CUDA);

Releasing the Handle

To release the handle:

dwImageStreamer_release(streamerCPU2CUDA);

To see a full demonstration of this workflow, please refer to Simple Image Streamer Sample.