LBitmap::UserFilter
#include "ltwrappr.h"
virtual L_INT LBitmap::UserFilter (pFilter);
LPUSERFLT pFilter; |
/* pointer to a structure */ |
Filters the bitmap based on a user-defined filter / mask. This function is similar to the spatial and binary filter functions. This function is available in the Raster Pro and above toolkits.
Parameter |
Description |
pFilter |
Pointer to an LPUSERFLT structure that contains information about the mask to be applied. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
With this function you can create a user-defined filter and apply it to the image. The selected filter is passed as a parameter to this function. The filter has a rectangular form (matrix) where the values are user-defined. It allows the creation of simple customized filters, where each value found in matrix is multiplied by the corresponding pixel, and then the specified operation is performed on the results.
Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.
When the filter is applied to pixels from the edge and you choose the sum operation, the edge rows and columns are duplicated. For example, if the pixel (-1, 5) is needed, the pixel (0, 5) is used instead.
This function does not support signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.
Required DLLs and Libraries
LTIMG For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application. |
See Also
Example
void TestFunction(LBitmap *pLeadBitmap)
{
/*In this example the high pass filter will be applied using user defined matrix*/
LPUSERFLT pFilter;
L_INT i, j;
/* Allocate the user filter structure. And also we need a (3x3) matrix with 9 elements. */
pFilter = (LPUSERFLT)malloc(sizeof(USERFLT) + 9 * sizeof(L_INT));
/* Initialize the array with factor used to apply the high pass filter */
for(i = 0; i < 3; i++)
{
for(j = 0; j < 3; j++)
{
if(j == 1 || i == 1)
{
if(j == 1 && i == 1)
pFilter->ufltMatrix[i * 3 + j] = 5;
else
pFilter->ufltMatrix[i * 3 + j] = -1;
}
else pFilter->ufltMatrix[i * 3 + j] = 0;
}
}
pFilter->uStructSize = sizeof(USERFLT);
pFilter->ufltWidth = 3;
pFilter->ufltHeight = 3;
pFilter->ufltCenter.x = 1;
pFilter->ufltCenter.y = 1;
pFilter->ufltDivisor = 1;
pFilter->nfltOffset = 0;
pFilter->ufltFlag = UD_SUM;
/* Apply the high pass custom filter */
pLeadBitmap->UserFilter (pFilter);
/* Free the filter */
free(pFilter);
}