ImageDev

SelectiveErosion2d

Erodes objects of a two-dimensional binary image conditionally to a local constraint.

Access to parameter description

For an introduction: This algorithm can be applied only on binary images. It is performed iteratively and at each step a foreground pixel is transformed into a background pixel if the number of background pixels in its 8-neighborhood is greater than or equal to a specified threshold.
Using a threshold of 1 amounts to applying a standard morphological erosion.

This operator is smoother than a standard erosion, and softens the appearance of the structuring element in the filtered image.

<b> (a) </b>
(a)
<b> (b) </b>
(b)
<b> (c) </b>
(c)
Figure 1. Selective erosion effect: (a) The binary input image,
(b) standard erosion with 3 iterations, (c) selective erosion with 3 iterations, threshold = 5

See also

Function Syntax

This function returns outputBinaryImage. 
// Function prototype
std::shared_ptr< iolink::ImageView >
selectiveErosion2d( std::shared_ptr< iolink::ImageView > inputBinaryImage,
                    uint32_t numberOfIterations,
                    uint32_t threshold,
                    std::shared_ptr< iolink::ImageView > outputBinaryImage = nullptr );
This function returns outputBinaryImage. 
// Function prototype.
selective_erosion_2d(input_binary_image: idt.ImageType,
                     number_of_iterations: int = 3,
                     threshold: int = 5,
                     output_binary_image: idt.ImageType = None) -> idt.ImageType
This function returns outputBinaryImage. 
// Function prototype.
public static IOLink.ImageView
SelectiveErosion2d( IOLink.ImageView inputBinaryImage,
                    UInt32 numberOfIterations = 3,
                    UInt32 threshold = 5,
                    IOLink.ImageView outputBinaryImage = null );

Class Syntax

Parameters

Parameter Name Description Type Supported Values Default Value
input
inputBinaryImage
The binary input image. Image Binary nullptr
input
numberOfIterations
The number of iterations. UInt32 >=1 3
input
threshold
The minimum number of background neighbors that is required to transform a foreground pixel into a background one. UInt32 [1, 8] 5
output
outputBinaryImage
The binary output image. Its size and type are forced to the same values as the input. Image nullptr
Parameter Name Description Type Supported Values Default Value
input
input_binary_image
The binary input image. image Binary None
input
number_of_iterations
The number of iterations. uint32 >=1 3
input
threshold
The minimum number of background neighbors that is required to transform a foreground pixel into a background one. uint32 [1, 8] 5
output
output_binary_image
The binary output image. Its size and type are forced to the same values as the input. image None
Parameter Name Description Type Supported Values Default Value
input
inputBinaryImage
The binary input image. Image Binary null
input
numberOfIterations
The number of iterations. UInt32 >=1 3
input
threshold
The minimum number of background neighbors that is required to transform a foreground pixel into a background one. UInt32 [1, 8] 5
output
outputBinaryImage
The binary output image. Its size and type are forced to the same values as the input. Image null

Object Examples

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

SelectiveErosion2d selectiveErosion2dAlgo;
selectiveErosion2dAlgo.setInputBinaryImage( polystyrene_sep );
selectiveErosion2dAlgo.setNumberOfIterations( 3 );
selectiveErosion2dAlgo.setThreshold( 5 );
selectiveErosion2dAlgo.execute();

std::cout << "outputBinaryImage:" << selectiveErosion2dAlgo.outputBinaryImage()->toString();

polystyrene_sep = imagedev.read_vip_image(imagedev_data.get_image_path("polystyrene_sep.vip"))

selective_erosion_2d_algo = imagedev.SelectiveErosion2d()
selective_erosion_2d_algo.input_binary_image = polystyrene_sep
selective_erosion_2d_algo.number_of_iterations = 3
selective_erosion_2d_algo.threshold = 5
selective_erosion_2d_algo.execute()

print("output_binary_image:", str(selective_erosion_2d_algo.output_binary_image))

ImageView polystyrene_sep = Data.ReadVipImage( @"Data/images/polystyrene_sep.vip" );

SelectiveErosion2d selectiveErosion2dAlgo = new SelectiveErosion2d
{
    inputBinaryImage = polystyrene_sep,
    numberOfIterations = 3,
    threshold = 5
};
selectiveErosion2dAlgo.Execute();

Console.WriteLine( "outputBinaryImage:" + selectiveErosion2dAlgo.outputBinaryImage.ToString() );

Function Examples

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

auto result = selectiveErosion2d( polystyrene_sep, 3, 5 );

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

polystyrene_sep = imagedev.read_vip_image(imagedev_data.get_image_path("polystyrene_sep.vip"))

result = imagedev.selective_erosion_2d(polystyrene_sep, 3, 5)

print("output_binary_image:", str(result))

ImageView polystyrene_sep = Data.ReadVipImage( @"Data/images/polystyrene_sep.vip" );

IOLink.ImageView result = Processing.SelectiveErosion2d( polystyrene_sep, 3, 5 );

Console.WriteLine( "outputBinaryImage:" + result.ToString() );