L_AddShadowBitmap

#include "l_bitmap.h"

L_LTIMGSFX_API L_INT L_AddShadowBitmap(pBitmap, uAngle, uThreshold, uFlags)

pBITMAPHANDLE pBitmap;	pointer to the bitmap handle
L_UINT uAngle;	shadow or light direction
L_UINT uThreshold;	threshold value
L_UINT uFlags;	flag

Adds shadows to the bitmap.

Parameter	Description
pBitmap	Pointer to the bitmap handle that references the bitmap on which to apply the effect.
uAngle	Angle value indicating the direction of the light source producing the shadow. Possible values are:
	Value	Meaning
	SHADOW_E	[0] East
	SHADOW_NE	[1] Northeast
	SHADOW_N	[2] North
	SHADOW_NW	[3] Northwest
	SHADOW_W	[4] West
	SHADOW_SW	[5] Southwest
	SHADOW_S	[6] South
	SHADOW_SE	[7] Southeast
uThreshold	Threshold value used to determine which pixels will be affected . Valid values range from 0 through 65535 for 64-bit, 48-bit and 16-bit grayscale images and from 0 through 4095 for 12-bit grayscale images. Otherwise, it is from 0 through 255. When uFlags = COLOR_RGB, any component (R, G, or B) of a pixel with a value less than the uThreshold value is not affected. When uFlags = COLOR_GRAY, any pixel where the master channel value is less than the uThreshold value is not affected.
uFlags	Type of the shadow. Possible values are:
	Value	Meaning
	SHADOW_CLR_RGB	[0] Shadows are colored.
	SHADOW_CLR_GRAY	[1] Shadows are grayscale.

Returns

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

Comments

This function applies a convolution matrix upon each color component and then combines the results in order to add shadows.

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.

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.

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

LTIMGSFX

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

#define MAKE_IMAGE_PATH(pFileName) TEXT("C:\\Users\\Public\\Documents\\LEADTOOLS Images\\")pFileName 
L_INT AddShadowBitmapExample(L_VOID) 
{ 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */ 
   /* Load a bitmap at its own bits per pixel  */ 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("ImageProcessingDemo\\Image3.cmp")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   /* Apply  shadow effect  to the image*/ 
   nRet = L_AddShadowBitmap(&LeadBitmap, SHADOW_SE, 0, SHADOW_CLR_GRAY); 
   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_EdgeDetectorBitmap, L_LensFlareBitmap, L_LightBitmap, L_AllocFTArray, L_ChangeHueSatIntBitmap, L_ColorReplaceBitmap, L_ColorThresholdBitmap, L_DFTBitmap, L_DirectionEdgeStatisticalBitmap, L_FFTBitmap, L_FreeFTArray, L_FrqFilterBitmap, L_FrqFilterMaskBitmap, L_FTDisplayBitmap, L_GetBitmapStatisticsInfo, L_GetFeretsDiameter, L_GetObjectInfo, L_GetRgnContourPoints, L_GetRgnPerimeterLength, L_MathFunctionBitmap, L_RevEffectBitmap, L_SegmentBitmap, L_SubtractBackgroundBitmap, L_UserFilterBitmap, L_BricksTextureBitmap, L_DeskewBitmap, L_DiffuseGlowBitmap, L_GlowFilterBitmap, L_HalfTonePatternBitmap, L_HighPassFilterBitmap, L_MaskConvolutionBitmap, L_PerspectiveBitmap, L_PlasmaFilterBitmap, L_PointillistBitmap, L_CanvasBitmap, L_CloudsBitmap, L_ColoredBallsBitmap, L_DiffuseGlowBitmap, L_DisplaceMapBitmap, L_FragmentBitmap, L_MosaicTilesBitmap, L_OffsetBitmap, L_RomanMosaicBitmap, L_VignetteBitmap, L_ZigZagBitmap
Topics:	Raster Image Functions: Artistic Effects
	Applying Artistic Effects