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LBitmap::GetStatisticsInfo

#include "ltwrappr.h"

virtual L_INT LBitmap::GetStatisticsInfo (pStatisticsInfo, uChannel, uStart, uEnd, uFlags = 0)

Returns statistical information about the bitmap.

Parameters

pSTATISTICSINFO pStatisticsInfo

Address of the STATISTICSINFO structure variable to be updated with the image information.

L_UINT uChannel

Flag that indicates the channel for which to get the information. This value is ignored if the bitmap is 12- or 16-bit grayscale. Possible values are:

Value	Meaning
CHANNEL_MASTER	[0] All channels *.
CHANNEL_RED	[1] Red channel only.
CHANNEL_GREEN	[2] Green channel only.
CHANNEL_BLUE	[3] Blue channel only.

L_UINT uStart

Indicates the beginning color value of the range for the evaluation.

L_UINT uEnd

Indicates the ending color value of the range for the evaluation.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

This function calculates statistical information about the bitmap.

The uStart and uEnd parameters designate the range of colors that will be taken in consideration for producing the results. Only the values between uStart and uEnd are used for the calculation of the results. The range of each one depends on the bits per pixel of the bitmap:

0 to 255 for 8 bits per component (RGB).
0 to 65535 for 16 bits.
0 to 4095 for 12 bits.

Support for 12 and 16-bit grayscale and 48 and 64-bit color images is available only in the Document/Medical toolkits.

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 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.

Calculating Master Channel Values

In order to speed up widely used image processing filters in LEADTOOLS, the grayscale value (master channel) of a colored image is calculated using the following formulas:

#define CalcGrayValue(r, g, b) ((L_UCHAR)(((L_UCHAR) (((2 * (L_UINT) (r)) + (5 * (L_UINT) (g)) + (L_UINT) (b) + 4) / 8)))) 
#define CalcGrayValue16(r, g, b) ((L_UINT16) (((2 * (L_UINT32) (r)) + (5 * (L_UINT32) (g)) + (L_UINT32) (b) + 4) / 8)) 
#define CalcGrayValue32(r, g, b) ((L_UINT32) (((2 * (L_UINT32) (r)) + (5 * (L_UINT32) (g)) + (L_UINT32) (b) + 4) / 8))

Required DLLs and Libraries

LTIMGEFX
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.

Example

L_INT LBitmap__GetStatisticsInfoExample(LBitmap *pLeadBitmap)  
{ 
   L_INT nRet; 
   STATISTICSINFO  StatisticsInfo;  
  
   /*Get statistical image information */ 
   nRet =pLeadBitmap->GetStatisticsInfo (&StatisticsInfo,CHANNEL_MASTER, 0, 255); 
   if(nRet !=SUCCESS) 
      return nRet; 
 
   return SUCCESS; 
}