DriveWorks SDK Reference
5.8.83 Release
For Test and Development only

Connected Components Workflow

Workflow

The workflow of the connected components module is:

  • Create connected components handle.
dwImageProperties inputProps{};
inputProps.width = width;
inputProps.height = height;
inputProps.type = DW_IMAGE_CUDA;
inputProps.format = DW_IMAGE_FORMAT_R_UINT8;
dwConnectedComponentsHandle_t ccl;
dwConnectedComponents_initialize(&ccl, &inputProps, cc);
dwConnectedComponentsHandle_t
struct dwConnectedComponentsObject * dwConnectedComponentsHandle_t
A pointer to the opaque handle for Connected Components.
Definition: ConnectedComponents.h:58
dwConnectedComponents_initialize
DW_API_PUBLIC dwStatus dwConnectedComponents_initialize(dwConnectedComponentsHandle_t *ccl, const dwImageProperties *inputDesc, dwContextHandle_t context)
Initializes connected components.
dwImageProperties::width
uint32_t width
Specifies the width of the image in pixels.
Definition: Image.h:401
DW_IMAGE_CUDA
@ DW_IMAGE_CUDA
Definition: Image.h:100
DW_IMAGE_FORMAT_R_UINT8
@ DW_IMAGE_FORMAT_R_UINT8
Definition: Image.h:130
dwImageProperties
Defines the properties of the image.
Definition: Image.h:397
  • Create input and output images.
dwImageHandle_t inputImageHandle;
dwImage_create(&inputImage, inputProps, cc);
// fill input image with actual data
// ...
dwImageProperties outputProps{};
outputProps.width = width;
outputProps.height = height;
outputProps.type = DW_IMAGE_CUDA;
outputProps.format = DW_IMAGE_FORMAT_RGBA_UINT8;
dwImageHandle labelsImageHandle;
dwImage_create(&labelsImageHandle, outputProps, cc);
dwImageHandle_t
struct dwImageObject * dwImageHandle_t
Definition: Image.h:110
dwImage_create
DW_API_PUBLIC dwStatus dwImage_create(dwImageHandle_t *const image, dwImageProperties properties, dwContextHandle_t const ctx)
Creates and allocates resources for a dwImageHandle_t based on the properties passed as input.
DW_IMAGE_FORMAT_RGBA_UINT8
@ DW_IMAGE_FORMAT_RGBA_UINT8
Definition: Image.h:152
  • Perform labeling.
dwConnectedComponents_setThreshold(127, ccl);
dwImageCUDA* inputImage = nullptr;
dwImage_getCUDA(&inputImage, inputImageHandle);
dwConnectedComponents_bindInput(inputImage, ccl);
dwImageCUDA* labelImage = nullptr;
dwImage_getCUDA(&labelImage, labelsImageHandle);
dwConnectedComponents_bindOutput(labelImage, ccl);
dwConnectedComponents_process(ccl);
dwConnectedComponents_bindInput
DW_API_PUBLIC dwStatus dwConnectedComponents_bindInput(const dwImageCUDA *image, dwConnectedComponentsHandle_t ccl)
Specifies input image to be processed.
dwConnectedComponents_process
DW_API_PUBLIC dwStatus dwConnectedComponents_process(dwConnectedComponentsHandle_t ccl)
Performs image labeling.
dwConnectedComponents_setThreshold
DW_API_PUBLIC dwStatus dwConnectedComponents_setThreshold(uint8_t threshold, dwConnectedComponentsHandle_t ccl)
Specifies threshold to binarize input image.
dwImage_getCUDA
DW_API_PUBLIC dwStatus dwImage_getCUDA(dwImageCUDA **const imageCUDA, dwImageHandle_t const image)
Retrieves the dwImageCUDA of a dwImageHandle_t.
dwImageCUDA
Defines a CUDA image.
Definition: Image.h:427

dwConnectedComponents_setThreshold is a function to define threshold for image binarization. Pixels which values are below the specified threshold are considered to be background pixels.

For a demonstration of this workflow, see Connected Components Sample.