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_geom_despeckle

This function is used to reduce speckle noise from an image by using the Crimmins algorithm.


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        HIGEAR hIGear, 
        const LPAT_RECT lpRect, 
        const AT_INT nIterations


Name Type Description
hIGear HIGEAR HIGEAR handle of image to be processed.
lpRect const LPAT_RECT Far pointer to an AT_RECT structure specifying the rectangular portion of the image on which to operate. If NULL, this 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.
nIterations const AT_INT Number of iterations to apply the despeckle filter.

Return Value:

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

Supported Raster Image Formats:

Grayscale – 8 bpp.


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HIGEAR   hIGear; /* HIGEAR handle of image */
AT_RECT lpRect; /* rectangle to process */
AT_INT nIterations;     /* Number of iterations */
IG_IP_geom_despeckle(hIGear, lpRect, nIterations);


This function reduces the speckle index of an image by sending the image through a geometric filter, which uses the complementary hulling technique. The method has the effect of reducing the undesired speckle noise while preserving the edges of the original image.

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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