RemoveBlob(Int32,Int32,Int32,Int32,Int32,Int32,Int32) Method

In This Topic

Removes blobs and ink blobs with a specified size margin. It is a very powerful tool for despeckling (removing parasites) from images without affecting the content.

Syntax

Visual Basic
C#
Delphi
JScript
Managed Extensions for C++
C++/CLI

'Declaration
 
Public Overloads Function RemoveBlob( _
   ByVal ImageID As Integer, _
   ByVal MinBlobWidth As Integer, _
   ByVal MinBlobHeight As Integer, _
   ByVal MaxBlobWidth As Integer, _
   ByVal MaxBlobHeight As Integer, _
   ByVal MinFillPercent As Integer, _
   ByVal MaxFillPercent As Integer _
) As GdPictureStatus

public GdPictureStatus RemoveBlob( 
   int ImageID,
   int MinBlobWidth,
   int MinBlobHeight,
   int MaxBlobWidth,
   int MaxBlobHeight,
   int MinFillPercent,
   int MaxFillPercent
)

public function RemoveBlob( 
    ImageID: Integer;
    MinBlobWidth: Integer;
    MinBlobHeight: Integer;
    MaxBlobWidth: Integer;
    MaxBlobHeight: Integer;
    MinFillPercent: Integer;
    MaxFillPercent: Integer
): GdPictureStatus;

public function RemoveBlob( 
   ImageID : int,
   MinBlobWidth : int,
   MinBlobHeight : int,
   MaxBlobWidth : int,
   MaxBlobHeight : int,
   MinFillPercent : int,
   MaxFillPercent : int
) : GdPictureStatus;

public: GdPictureStatus RemoveBlob( 
   int ImageID,
   int MinBlobWidth,
   int MinBlobHeight,
   int MaxBlobWidth,
   int MaxBlobHeight,
   int MinFillPercent,
   int MaxFillPercent
)

public:
GdPictureStatus RemoveBlob( 
   int ImageID,
   int MinBlobWidth,
   int MinBlobHeight,
   int MaxBlobWidth,
   int MaxBlobHeight,
   int MinFillPercent,
   int MaxFillPercent
)

Parameters

ImageID: GdPicture image identifier. Only 1 bit per pixel images with black and white palette are supported.
MinBlobWidth: Minimum Width of Blob considered for removal.
MinBlobHeight: Minimum Height of Blob considered for removal.
MaxBlobWidth: Maximum Width of Blob considered for removal.
MaxBlobHeight: Maximum Height of Blob considered for removal.
MinFillPercent: Minimum percentage of black pixels within blob compared to blob bounding rectangle. Range [1-99]
MaxFillPercent: Maximum percentage of black pixels within blob compared to blob bounding rectangle. Range [2-100]

Return Value

A member of the GdPictureStatus enumeration.

Remarks

This method is used in the "Document Clean Up" C# Demo.

To use it as a despeckling method you need to: 1. Know the range of the noise size (which is usually smaller than a character size). 2. Set the MinFillPercent and MaxFillPercent to 1 and 100 respectively. 3. Set MinBlobWidth and MinBlobHeight to 1 and 2 respectively. 4. Set MaxBlobWidth and MaxBlobHeight to a value smaller than the size of a character in your image. The size of the character is highly dependent on the dpi of the image and the content. The higher the dpi, the higher the MaxBlobWidth and MaxBlobHeight should be.

This method requires the Image Documents component to run.

Example

Removing blobs from a tiff and saving as a png.

using (GdPictureImaging gdpictureImaging = new GdPictureImaging())
{
    int imageID = gdpictureImaging.CreateGdPictureImageFromFile("image.tif", false);
 
    int minBlobWidth = 50;
    int minBlobHeight = 50;
    int maxBlobWidth = 1000;
    int maxBlobHeight = 1000;
    int minFillPercent = 90;
    int maxFillPercent = 100;
 
    gdpictureImaging.RemoveBlob(imageID, minBlobWidth, minBlobHeight, maxBlobWidth, maxBlobHeight, minFillPercent, maxFillPercent);
    gdpictureImaging.SaveAsPNG(imageID, "image.png");
    gdpictureImaging.ReleaseGdPictureImage(imageID);
}

Reference

GdPictureImaging Class
GdPictureImaging Members
Overload List