ImageGear for C and C++ on Linux v20.0 - Updated
API Reference Guide > Core Component API Reference > Core Component Functions Reference > Image Processing Functions > IG_IP_despeckle

Despeckle is used to help reduce the amount of noise in the image.


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        HIGEAR hIGear, 
        const LPAT_RECT lpRect 


Name Type Description
hIGear HIGEAR HIGEAR handle of image.
lpRect const LPAT_RECT Far pointer to an AT_RECT struct specifying the rectangular portion of the image to operate on. If NULL, the operation will be performed on the entire image. Before ImageGear performs this operation, it will check to see if an internal flag has been set to TRUE to make a mask active for this HIGEAR image. If a mask is active, and a valid pointer to a mask can be found, ImageGear will override the settings passed to this structure in favor of the non-rectangular ROI defined by the mask.

Return Value:

Returns the number of ImageGear errors that occurred during this function call.

Supported Raster Image Formats:

All pixel formats supported by ImageGear for C and C++, except:
Indexed images with non-grayscale palette.


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HIGEAR hIGear;  /* HIGEAR handle of image */
nErrCount        = IG_IP_despeckle ( hIGear, NULL );


Single pixels and pixel spurs on letters and graphics are removed while leaving the solid areas alone. It is typically used on 1-bit document images.

The despeckle operation performs a 3x3 median filter on the image. For each 3x3 neighborhood of pixels in the original image, a single pixel is produced in the output image. In this case the output is the median of the 9 values in the 3x3 neighborhood.

This function, like other ImageGear Image Processing and Clipboard API calls, takes an AT_RECT structure as an argument, so that you can process a rectangular sub-region of an image. However, before ImageGear performs the operation specified by this function, it will check to see if an internal flag has been set to TRUE, indicating that a mask HIGEAR should be used with the image. If the flag is set to TRUE, and a valid pointer to a mask image has been assigned, ImageGear will override the settings passed to the AT_RECT structure and use the non-rectangular ROI defined by the mask HIGEAR. To create a non-rectangular region of interest, call IG_IP_NR_ROI_to_HIGEAR_mask().

Please see the descriptions of IG_IP_NR_ROI_mask_associate() and IG_IP_NR_ROI_to_HIGEAR_mask() functions for more details.
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