Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits. |
#include "l_bitmap.h"
L_LTIMGCLR_API L_INT L_HistoEqualizeBitmap(pBitmap, uFlags)
pBITMAPHANDLE pBitmap; |
/* pointer to the bitmap handle */ |
L_UINT32 uFlags; |
/* flag */ |
Linearizes the number of pixels, in a bitmap, based on the specified color space. This function is also useful for pre-processing images for the purpose of improving barcode recognition results.
Parameter |
Description |
|
pBitmap |
Pointer to the bitmap handle referencing the bitmap to be changed. |
|
uFlags |
Flag that indicates which color space to equalize. Possible values are: |
|
|
Value |
Meaning |
|
RGB_SPACE |
[0x0001] Linearizes the number of pixels across the RGB color space.(separated channels). |
|
YUV_SPACE |
[0x0002] Linearizes the number of pixels across the YUV color space.(Best results). |
|
GRAY_SPACE |
[0x0004] Linearizes the number of pixels per gray level in a gray level representation of the image. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
To update a status bar or detect a user interrupt during execution of this function, refer to L_SetStatusCallback.
Previously this function only equalized the number of pixels per gray level, using a gray level representation of the image. This functionality is now obtained by passing GRAY_SPACE for uFlags.
For the best results, set uFlags to YUV_SPACE.
This function can process the whole image or a region of the image.
This function supports 12 and 16-bit grayscale and 48 and 64-bit color images. Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available in the Document and Medical Imaging toolkits.
This function does not support 32-bit grayscale images. It returns the error code ERROR_GRAY32_UNSUPPORTED if a 32-bit grayscale image is passed to this function.
Required DLLs and Libraries
LTIMGCLR For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application. |
Platforms
Win32, x64.
See Also
Example
For complete sample code, refer to the CHILD.C module of the DEMO example. This example loads a bitmap and applies histogram equalization.
#define MAKE_IMAGE_PATH(pFileName) TEXT("C:\\Users\\Public\\Documents\\LEADTOOLS Images\\")pFileName L_INT HistoEqualizeBitmapExample(L_VOID) { L_INT nRet; BITMAPHANDLE LeadBitmap; /* Bitmap handle to hold the loaded image. */ /* Load the bitmap, keeping the bits per pixel of the file */ nRet = L_LoadBitmap (MAKE_IMAGE_PATH(TEXT("IMAGE1.CMP")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); if(nRet !=SUCCESS) return nRet; /* Histogram equalize the bitmap */ nRet = L_HistoEqualizeBitmap(&LeadBitmap, YUV_SPACE ); 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); return SUCCESS; }