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L_DisplaceMapBitmap

Summary

Displaces bitmap pixels horizontally and vertically according to the values of the displacement map image.

Syntax

#include "l_bitmap.h"

L_LTIMGEFX_API L_INT L_DisplaceMapBitmap(pBitmap, pDisplacementMap, uHorzFact, uVertFact, crFill, uFlags)

Parameters

pBITMAPHANDLE pBitmap

Pointer to the bitmap handle that references the bitmap on which to apply the effect.

pBITMAPHANDLE pDisplacementMap

Pointer to the bitmap handle that references the displacement map bitmap.

L_UINT uHorzFact

Horizontal displacement factor, in percent of the bitmap dimensions. The valid range is from 0 to 100.

L_UINT uVertFact

Vertical displacement factor, in percent of the bitmap dimensions. The valid range is from 0 to 100.

The COLORREF value that specifies the fill color for any exposed areas. You can specify a COLORREF value, such as the return value of the Windows RGB macro, or you can use the PALETTEINDEX macro to specify a palette color.

L_UINT uFlags

Flags that indicate how to handle exposed areas, and the way to use the displacement map image. You can use a bitwise OR ( | ) to specify one flag from each group.

The following are the flags that indicate how to handle exposed areas:

Value	Meaning
FILL_CLR	[0x0000] Fill any exposed areas with `crFill`
FILL_RPT	[0x0001] Stretch the image edges to fill the exposed area.
FILL_NOCHG	[0x0002] Leave the exposed area as is, without changing it.
FILL_WRAP	[0x0003] Fill any exposed area with the opposite side of the image.

The following are the flags that indicate the way to use the displacement map image:

Value	Meaning
DSPL_STRETCH	[0x0010] Stretch the displacement map image over the entire image area.
DSPL_TILE	[0x0000] Repeat the displacement map image to cover the image area.

Returns

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

Comments

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 effect shifts image pixels according to the values of the displacement map. Red values in the displacement map shift the original pixels horizontally. Green values in the displacement map shift the original values vertically. Blue values are ignored. A displacement map value of 128 means not to shift anything. A displacement map value of 0 means to shift pixels the complete vertical or horizontal percentage, to the left or down. A displacement map value of 255 means to shift pixels the complete vertical or horizontal percentage, to the right or up.

Displacement maps modify the geometry of the object. As a result, pixel shifts and forms may be added to the image, and the image may be warped or distorted.

For an example, click here

If the bitmap has a region, the effect will be applied on the region only.

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.

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.

Displacement Function - Before

Displacement Function - After

View additional platform support for this Displacement function.

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.

Example

L_INT DisplaceMapBitmapExample(L_VOID) 
{ 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */ 
   BITMAPHANDLE DisplacementMap;   /* Bitmap handle for the displacement map */ 
 
   /* Load a bitmap at its own bits per pixel  */ 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("Image2.jpg")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   /* Load a displacement map at its own bits per pixel  */ 
   nRet = L_LoadBitmap(MAKE_IMAGE_PATH(TEXT("Image1.jpg")), &DisplacementMap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   /* Shift the image according to the displacement map*/ 
   nRet = L_DisplaceMapBitmap(&LeadBitmap, &DisplacementMap, 5, 5, RGB(0, 0, 0), FILL_CLR | DSPL_TILE); 
   if (nRet != SUCCESS) 
      return nRet; 
 
   if (DisplacementMap.Flags.Allocated) 
      L_FreeBitmap(&DisplacementMap); 
 
   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; 
}