Class MedianBlurFilter

A filter to apply Median blur to an image.

Inheritance
System.Object
MedianBlurFilter
Implements
Namespace: IronBarCode
Assembly: IronBarCode.dll
Syntax
public class MedianBlurFilter : Object, IImageFilter

Salt-and-pepper specks scattered across a scan are cleared by MedianBlurFilter, which replaces each pixel with the median value of its neighborhood. Unlike an averaging blur, a median pass removes isolated bright and dark dots without smearing the sharp transitions between bars, so the edges that a decoder depends on stay crisp. It is the filter to reach for when a thresholded or low-quality scan is peppered with stray pixels rather than uniformly grainy; for a gentler, edge-softening smooth of general noise, a Gaussian blur is the alternative.

The filter implements IImageFilter and is added to the ImageFilterCollection on BarcodeReaderOptions.ImageFilters, where filters run in collection order before the read. A developer constructs it, adds it to the collection, and passes the options to BarcodeReader.Read. The parameterless constructor uses a KernelSize of 5, the size of the neighborhood sampled for each median. KernelSize must be an odd value greater than 0; the MedianBlurFilter(int kernelSize) overload or the KernelSize property raises it for stronger speck removal on heavier noise.

using IronBarCode;

var options = new BarcodeReaderOptions
{
    ImageFilters = new ImageFilterCollection { new MedianBlurFilter() }
};
var results = BarcodeReader.Read("speckled.png", options);

The image correction how-to covers the correction filters on a sample barcode, and the imperfect barcode example reads a degraded image through a filter pipeline.

Constructors

MedianBlurFilter()

Initializes a new instance of the MedianBlurFilter class.

Declaration
public MedianBlurFilter()

MedianBlurFilter(Int32)

Initializes a new instance of the MedianBlurFilter class.

Declaration
public MedianBlurFilter(int kernelSize)
Parameters
Type Name Description
System.Int32 kernelSize

Size of the kernel to apply Median blur.

Properties

KernelSize

Size of the kernel to apply Median blur. Must be an odd value greater than 0. Default = 5.

Declaration
public int KernelSize { get; set; }
Property Value
Type Description
System.Int32

Implements