ImageDev

OpeningLineMaximum

Performs a maximal linear opening.

Access to parameter description

For an introduction: This algorithm computes the union of the openings in several directions (binary case) or the maximum of these openings (grayscale case).
It is very useful for filtering circular shapes, because it removes blobs in all directions (the circular ones first).
Like a classical opening transform, combining this algorithm with a subtraction to the original image and an appropriate threshold performs a Top Hat well adapted to circular bright object detection.
In the 2D case, directions are regularly sampled around the unit circle (starting with a horizontal right oriented direction). In the 3D case, a unit sphere is regularly sampled (starting with a vertical upper oriented direction).

See also

Function Syntax

This function returns outputImage. 
// Function prototype
std::shared_ptr< iolink::ImageView >
openingLineMaximum( std::shared_ptr< iolink::ImageView > inputImage,
                    int32_t kernelRadius,
                    int32_t directionNumber,
                    std::shared_ptr< iolink::ImageView > outputImage = NULL );

Class Syntax

Parameters

Parameter Name Description Type Supported Values Default Value
input
inputImage
The input image. Image Binary, Label, Grayscale or Multispectral nullptr
input
kernelRadius
The length of the linear structuring element in pixels. Int32 >=1 3
input
directionNumber
The number of directions for linear opening. Int32 >=1 4
output
outputImage
The output image. Its dimensions and type are forced to the same values as the input image. Image nullptr

Object Examples

auto foam = readVipImage( std::string( IMAGEDEVDATA_IMAGES_FOLDER ) + "foam.vip" );

OpeningLineMaximum openingLineMaximumAlgo;
openingLineMaximumAlgo.setInputImage( foam );
openingLineMaximumAlgo.setKernelRadius( 3 );
openingLineMaximumAlgo.setDirectionNumber( 4 );
openingLineMaximumAlgo.execute();

std::cout << "outputImage:" << openingLineMaximumAlgo.outputImage()->toString();

Function Examples

auto foam = readVipImage( std::string( IMAGEDEVDATA_IMAGES_FOLDER ) + "foam.vip" );

auto result = openingLineMaximum( foam, 3, 4 );

std::cout << "outputImage:" << result->toString();