L_GetBitmapStatisticsInfo

#include "l_bitmap.h"

L_LTIMGEFX_API L_INT L_GetBitmapStatisticsInfo (pBitmap, pStatisticsInfo, uChannel, nStart, nEnd, uFlags)

pBITMAPHANDLE pBitmap;

pointer to the bitmap handle

pSTATISTICSINFO pStatisticsInfo;

address of the STATISTICSINFO structure variable to be updated

L_UINT uChannel;

the color planes to be evaluated

L_INT nStart;

the starting color value

L_INT nEnd;

the ending color value

L_UINT32 uFlags;

flags

Returns statistical information about the bitmap.

Parameter Description
pBitmap Pointer to the bitmap handle that references the bitmap on which to apply the effect.
pStatisticsInfo Address of the STATISTICSINFO structure variable to be updated with the image information.
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.
nStart Indicates the beginning color value of the range for the evaluation.
nEnd Indicates the ending color value of the range for the evaluation.
uFlags Reserved for future use. Must be 0.

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

This function calculates statistical information about the bitmap.

The nStart and nEnd parameters designate the range of colors that will be taken in consideration for producing the results. Only the values between nStart and nEnd are used for the calculation of the results. The range of each one depends on the bits per pixel of the bitmap: in the case of 8 bits per component (RGB), the range is between 0 and 255; for 16 bits, the range is 0 through 65535 for unsigned images and from -32768 to 32767 for signed images; and for 12 bits, the range is 0 through 4095.

This function supports signed data images. 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.

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, Linux.

See Also

Functions:

L_ConvertToColoredGray, L_GrayScaleBitmap, L_GrayScaleBitmapExt, L_IsGrayScaleBitmap, L_AddShadowBitmap, L_AllocFTArray, L_ChangeHueSatIntBitmap, L_ColorReplaceBitmap, L_ColorThresholdBitmap, L_DFTBitmap, L_DirectionEdgeStatisticalBitmap, L_FFTBitmap, L_FreeFTArray, L_FrqFilterBitmap, L_FrqFilterMaskBitmap, L_FTDisplayBitmap, L_GetFeretsDiameter, L_GetObjectInfo, L_GetRgnContourPoints, L_GetRgnPerimeterLength, L_MathFunctionBitmap, L_RevEffectBitmap, L_SegmentBitmap, L_SubtractBackgroundBitmap, L_UserFilterBitmap

Topics:

Raster Image Functions: Image Analysis

 

Color Halftone and Halftone Images

Example

L_INT GetBitmapStatisticsInfoExample(L_VOID) 
{ 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */ 
   STATISTICSINFO  StatisticsInfo;  
     
   /* Load a bitmap at 24 bits per pixel  */ 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("ImageProcessingDemo\\Image3.cmp")), &LeadBitmap, sizeof(BITMAPHANDLE), 24, ORDER_BGR, NULL, NULL);  
   if(nRet !=SUCCESS) 
      return nRet; 
 
   /*Get statistical image information */ 
   nRet = L_GetBitmapStatisticsInfo (&LeadBitmap, &StatisticsInfo,CHANNEL_MASTER, 0, 255, 0); 
   if(nRet !=SUCCESS) 
      return nRet; 
   //free Bitmap 
   if(LeadBitmap.Flags.Allocated)   
      L_FreeBitmap(&LeadBitmap); 
   return SUCCESS; 
} 
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