L_IntensityDetectBitmap

#include "l_bitmap.h"

L_LTIMGCLR_API L_INT L_IntensityDetectBitmap(pBitmap, uLow, uHigh, crInColor, crOutColor, uChannel, uFlags)

pBITMAPHANDLE pBitmap;	pointer to the bitmap handle
L_UINT uLow;	lowest intensity to detect
L_UINT uHigh;	highest intensity to detect
COLORREF crInColor;	color used to fill the inner segment
COLORREF crOutColor;	color used to fill the outer segment
L_UINT uChannel;	channel to be processed
L_UINT32 uFlags;	flags

Applies binary segmentation to a bitmap by filtering the specified bitmap to detect colors in a specified intensity range, in the specified color channel(s).

Parameter	Description
pBitmap	Pointer to the bitmap handle referencing the bitmap.
uLow	Lowest intensity to detect. Possible values range from 0 - 65535 for 64-bit, 48-bit and 16-bit grayscale images and from 0 - 4095 for 12-bit grayscale images. Otherwise, it is from 0 to 255..
uHigh	Highest intensity to detect. Possible values range from 0 - 65535 for 64-bit, 48-bit and 16-bit grayscale images and from 0 - 4095 for 12-bit grayscale images. Otherwise, it is from 0 to 255.
crInColor	The color used to fill those pixels having an intensity value between uLow and uHigh. This parameter has no effect if the uChannel parameter is set to IDB_CHANNEL_MASTER. If for example the uChannel parameter is set to IDB_CHANNEL_RED, then the red component of crInColor will be used to fill the pixels having a red component value between uLow and uHigh.
crOutColor	The color used to fill those pixels having an intensity value less than uLow or greater than uHigh. This parameter has no effect if the uChannel parameter is IDB_CHANNEL_MASTER. If for example the uChannel parameter is set to IDB_CHANNEL_RED, then the red component of crOutColor will be used to fill the pixels having a red component value less than uLow or greater than uHigh.
uChannel	A value that indicates the channel to process. Possible values are:
	Value	Meaning
	IDB_CHANNEL_MASTER</b>*	[0x0000] Grayscale Channel.
	IDB_CHANNEL_RED	[0x0001] Red Channel.
	IDB_CHANNEL_GREEN	[0x0010] Green Channel.
	IDB_CHANNEL_BLUE	[0x0100] Blue Channel.
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 is useful for pre-processing images to improve barcode recognition results.

The image is divided into two parts: inner and outer, corresponding to the values of uLow and uHigh.

Process 2 or more channels at a time by OR-ing two or more flags.

To obtain the same result as the old L_IntensityDetectBitmap(pBitmap, uLow, uHigh) of version 13 and earlier, pass the following parameters:

L_IntensityDetectBitmap(pBitmap, uLow, uHigh, RGB(0, 0, 0), RGB(255, 255, 255), CHANNEL_RED | CHANNEL_GREEN | CHANNEL_BLUE);

This function also 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.

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

*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

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, Linux.

Example

This example loads a bitmap and applies the filter on it.

#define MAKE_IMAGE_PATH(pFileName) TEXT("C:\\Users\\Public\\Documents\\LEADTOOLS Images\\")pFileName 
L_INT IntensityDetectBitmapExample(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("dirty_barcode.jpg")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   /* Apply the filter*/ 
   nRet = L_IntensityDetectBitmap(&LeadBitmap, 128, 255, RGB(0, 0, 0), RGB(255, 255, 255), IDB_CHANNEL_MASTER, 0); 
   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; 
}

Help Version 19.0.2017.10.27

LEADTOOLS Raster Imaging C API Help

Introduction

Version History

Getting Started

LEADTOOLS Raster Imaging Features

Redistributables/Files To Be Included With Your Application

Functions:	L_AutoBinaryBitmap, L_IntensityDetectBitmap, L_SharpenBitmap, L_PosterizeBitmap, L_MosaicBitmap, L_EmbossBitmap, L_AverageFilterBitmap, L_MedianFilterBitmap, L_AddBitmapNoise, L_SpatialFilterBitmap, L_BinaryFilterBitmap, L_MaxFilterBitmap, L_MinFilterBitmap, L_OilifyBitmap, L_SolarizeBitmap, L_DlgIntensityDetect, L_WindowLevel, L_ChannelMix, L_DeinterlaceBitmap, L_DesaturateBitmap, L_EdgeDetectStatisticalBitmap, L_LightControlBitmap, L_SmoothEdgesBitmap, L_AutoColorLevelBitmap, L_ColorLevelBitmap, L_CorrelationBitmap, L_GrayScaleToDuotone, L_GrayScaleToMultitone, L_HolesRemovalBitmapRgn, L_SelectiveColorBitmap, L_SkeletonBitmap, L_HighPassFilterBitmap, L_BricksTextureBitmap, L_DeskewBitmap, L_DiffuseGlowBitmap, L_GlowFilterBitmap, L_HalfTonePatternBitmap, L_HighPassFilterBitmap, L_MaskConvolutionBitmap, L_PerspectiveBitmap, L_PlasmaFilterBitmap, L_PointillistBitmap, L_AutoBinarizeBitmap, L_DynamicBinaryBitmap, L_AutoBinaryBitmap
Topics:	Raster Image Functions: Modifying Intensity Values
	Changing Brightness and Contrast
	Raster Image Functions: Changing Brightness and Contrast
	Using Color Values in LEADTOOLS
	Raster Image Functions: Detecting and Enhancing Edges and Lines