#include "l_bitmap.h"

L_LTIMGCLR_API L_INT L_ColorSeparateBitmap(pBitmap, ppBitmap, uStructSize, uFlags)

Separates the specified bitmap by color plane to produce one grayscale image per plane. You can specify any of several color-space models, including CMYK.



Pointer to the bitmap handle referencing the bitmap to separate.


An array of pointers to the bitmap handles that will reference the grayscale bitmaps when they are created.

L_UINT uStructSize

Size in bytes, of the structures pointed to by ppBitmap, for versioning. Use sizeof(BITMAPHANDLE).

The pointers in the array should be in the appropriate order, which in most cases is the order of the letters in the name. For example, for CMY separation, the first pointer should be for the cyan plane, the second for magenta, and the third for yellow. The only exception is RGB, which should be in BGR (blue, green, red) order.

L_UINT uFlags

The type of separation.  Possible values are:

Value Meaning
COLORSEP_RGB [0x0000] Create images for three RGB planes.
COLORSEP_CMYK [0x0001] Create images for four CMYK planes.
COLORSEP_HSV [0x0002] Create images for three HSV planes.
COLORSEP_HLS [0x0003] Create images for three HLS planes.
COLORSEP_CMY [0x0004] Create images for three CMY planes.
COLORSEP_YUV [0x0005] Create images for three YUV planes.
COLORSEP_XYZ [0x0006] Create images for three XYZ planes.
COLORSEP_LAB [0x0007] Create images for three LAB planes.
COLORSEP_YCrCb [0x0008] Create images for three YCrCb planes.
COLORSEP_SCT [0x0009] Create images for three SCT planes.


Value Meaning
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.

The supported color-space models are RGB, CMYK, CMY, HSV, HLS, YUV, XYZ, LAB, YCrCb and SCT.

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.

If the pBitmap is a 48 or 64-bit bitmap, then the created bitmaps are 16 bit grayscale. Otherwise the created bitmaps are 8 bit grayscale.

To update a status bar or detect a user interrupt during execution of this function, refer to L_SetStatusCallback.

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


Win32, x64, Linux.

See Also




For complete sample code, refer to the CHILD.C module of the DEMO example.
This example creates color separations and merges them.

L_INT ColorSeparateBitmapExample(L_VOID) 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;                  /* Bitmap handle to hold the loaded image */ 
   BITMAPHANDLE ColorPlanes[4];              /* Array of bitmap handles */ 
   pBITMAPHANDLE pColorPlanes[4];          /* Array of pointers to bitmap handles */ 
   /* Assign bitmap handle addresses to the pointers */ 
   pColorPlanes[0] = &ColorPlanes[0]; 
   pColorPlanes[1] = &ColorPlanes[1]; 
   pColorPlanes[2] = &ColorPlanes[2]; 
   pColorPlanes[3] = &ColorPlanes[3]; 
   /* Load the bitmap, at its own bits per pixel */ 
   nRet = L_LoadBitmap (MAKE_IMAGE_PATH(TEXT("sample5.cmp")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   /* Separate the color planes */ 
   nRet = L_ColorSeparateBitmap(&LeadBitmap, pColorPlanes, sizeof(BITMAPHANDLE), COLORSEP_CMYK); 
   if(nRet !=SUCCESS) 
      return nRet; 
   /* Free the bitmap */ 
   /* Merge the color planes */ 
   nRet = L_ColorMergeBitmap(&LeadBitmap, pColorPlanes, sizeof(BITMAPHANDLE), COLORSEP_CMYK); 
   if(nRet !=SUCCESS) 
      return nRet; 
   /* Free the bitmaps used for color planes */ 
   nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Result.BMP")), &LeadBitmap, FILE_BMP, 24, 0, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   //free bitmap  
   return SUCCESS; 

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