ImageGear for C and C++ on Windows v19.10 - Updated
IG_IP_remove_tilt
API Reference Guide > Core Component API Reference > Core Component Functions Reference > Image Processing Functions > IG_IP_remove_tilt

This function computes the best-fit plane for an image, and then subtracts that plane from the image to produce the output.

Declaration:

 
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AT_ERRCOUNT ACCUAPI IG_IP_remove_tilt(
        HIGEAR hIGear, 
        const LPAT_RECT lpRect, 
        AT_BOOL bRemoveMean
);

Arguments:

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.
bRemoveMean AT_BOOL Remove the mean from the de-tilted image, giving it zero-mean statistics.

Return Value:

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

Supported Raster Image Formats:

Grayscale - 8, 16, 32 bpp.

Sample:

Image Processing

Example:

 
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HIGEAR hIGear; /* HIGEAR handle of image */
AT_BOOL         bRemoveMean;    /* TRUE = remove mean */
AT_RECT         lpRect; /* rectangle to process */
...
IG_IP_remove_tilt( hIGear, lpRect, bRemoveMean);
...

Remarks:

This function is very handy for correcting illumination gradients in a poorly digitized image.

If bRemoveMean argument is set to TRUE, then remove mean from 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.