#include "l_bitmap.h"
L_LTIMGCOR_API L_INT L_FrqFilterBitmap(pFTArray, prcRange, uFlags)
pFTARRAY pFTArray; |
pointer to structure |
LPRECT prcRange; |
pointer to range rectangle |
L_UINT uFlags; |
flags |
Filters the frequency harmonics data produced by a Fourier Transform function using a range rectangle.
Parameter | Description | |
pFTArray | Pointer to an FTARRAY structure. The acxData member of the FTARRAY structure is a two-dimensional array holding the frequency components. | |
prcRange | Specifies the filter dimension that will be applied, it represents the frequency range to be kept or removed. The left value refers to the minimum X harmonic, the right refers to the maximum X harmonic, the top refers to the minimum Y harmonic and the bottom refers to the maximum Y harmonic. The maximum X harmonic equals Width 1 and the maximum Y harmonic equals Height 1. | |
uFlags | Flags that indicate the operation to be performed on the specified X and Y harmonics ranges. You can use a bit wise OR (|) to specify one flag from each group. | |
The following flags represent operations on the X harmonics range: | ||
Value | Meaning | |
FRQ_INSIDE_X | [0x0001] Keep the X harmonics inside X range and remove outside ones. | |
FRQ_OUTSIDE_X | [0x0002] Remove the X harmonics inside X range and keep outside ones. | |
The following flags represent operations on the Y harmonics range: | ||
Value | Meaning | |
FRQ_INSIDE_Y | [0x0010] Keep the Y harmonics inside Y range and remove outside ones. | |
FRQ_OUTSIDE_Y | [0x0020] Remove the Y harmonics inside Y range and keep outside ones. |
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
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.
This function is used only when working with Fourier Transform functions.
This function does not support 12 and 16-bit grayscale and 48 and 64-bit color images. If the image is 12 and 16-bit grayscale and 48 and 64-bit color, the function will not return an error.
Before using this function, call the L_AllocFTArray function to allocate a FTARRAY structure large enough to hold the Fourier Transform coefficients for pBitmap. When the array is no longer needed, free the allocated array by calling the L_FreeFTArray function.
To update a status bar or detect a user interrupt during execution of this function, refer to L_SetStatusCallback.
Required DLLs and Libraries
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application. |
Win32, x64, Linux.
this example filters the acxData of a pFTARRAY structure produced by the Fast Fourier Transform function
#define MAKE_IMAGE_PATH(pFileName) TEXT("C:\\Users\\Public\\Documents\\LEADTOOLS Images\\")pFileName
L_INT FrqFilterBitmapExample(L_VOID)
{
L_INT nRet;
BITMAPHANDLE LeadBitmap;
RECT rcRange;
pFTARRAY pFTArray;
nRet = L_LoadBitmap (MAKE_IMAGE_PATH(TEXT("ImageProcessingDemo\\FourierTransform.jpg")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL);
if(nRet !=SUCCESS)
return nRet;
rcRange.left = 0;
rcRange.right = LeadBitmap.Width / 4;
rcRange.top = 0;
rcRange.bottom = LeadBitmap.Height / 2;
/*Allocate FT buffer*/
nRet = L_AllocFTArray(&LeadBitmap, &pFTArray, sizeof(FTARRAY), 0);
if(nRet !=SUCCESS)
return nRet;
/*lpFTData is known*/
/* filters the frequencies*/
nRet = L_FrqFilterBitmap(pFTArray, &rcRange, FRQ_INSIDE_X | FRQ_INSIDE_Y);
if(nRet !=SUCCESS)
return nRet;
nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Result.BMP")), &LeadBitmap, FILE_BMP, 24, 0, NULL);
if(nRet !=SUCCESS)
return nRet;
//free bitmap
if(LeadBitmap.Flags.Allocated)
L_FreeBitmap(&LeadBitmap);
L_FreeFTArray(pFTArray,0);
return SUCCESS;
}
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