L_PixelateBitmap

#include "l_bitmap.h"

L_LTIMGSFX_API L_INT L_PixelateBitmap(pBitmap, uCellWidth, uCellHeight, uOpacity, CenterPt, uFlags);

Divides the bitmap into rectangular or circular cells and then recreates the image by filling those cells with the minimum, maximum, or average pixel value, depending upon the effect that was selected.

Parameters

pBITMAPHANDLE pBitmap

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

L_UINT uCellWidth

Value that represents the width of a rectangular cell, the number of rectangular cells present across the width of the bitmap, the number of cells around the center point of a circular cell, or the length in degrees of each cell around the center point of a circular cell, based on the flags set in uFlags.

If uFlags contains:	then, uCellWidth contains:	and the range of possible values for uCellWidth is:
PIX_RAD | PIX_WFRQ	the number of cells around the CenterPt. That is, the circle around the CenterPt is divided into uCellWidth equal parts, as shown below:	1 to 360. The circle can be divided into anywhere from 1 to 360 equal parts.
PIX_RAD | PIX_WPER	the size, in degrees of the cells around the CenterPt. That is, the circle around the CenterPt is divided into cells of uCellWidth degrees, as shown below:	1 to 360. The circle can be divided into cells of 1 degree to 360 degrees.
PIX_RECT | PIX_WFRQ	the number of cells present across the width of the bitmap	1 to the image width, if there is no region. If there is a region, then the range of values is just the region width.
PIX_RECT | PIX_WPER	the width of each rectangular cell, in pixels	1 to the image width, if there is no region. If there is a region, then the range of values is just the region width.

L_UINT uCellHeight

Value that represents the height of a rectangular cell, the number of rectangular cells present across the height of the bitmap, the number of cells along the radius of a circular cell, or the length of each cell along the radius of a circular cell, based on the flags set in uFlags.

L_UINT uOpacity

Value that represents how transparent the cells are, compared to the original pixels. This is a percentage. Possible values are 0 100. (0 is the total transparency and 100 is the total opacity.)

POINT CenterPt

Point that represents the center of revolution when circular cells are used. This parameter will be ignored if PIX_RECT is set in uFlags.

L_UINT uFlags

Flags that indicate the values used to fill the cells, the shape of the cells, and what type of data is in the uCellWidth and uCellHeight parameters. You can use a bitwise OR (|) to specify one flag from each group.

The following are the flags indicate what values will be used to fill the cells:

The following are the flags that indicate the shape of the cells:

The following are the flags the indicate what information is contained in the uCellWidth and uCellHeight parameters:

Returns

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 function will divide the image into rectangular or circular cells.

The uFlags parameter indicates whether to use rectangular or circular cells and indicates the type of information in the other parameters.

If the image is divided into circular cells by setting PIX_RAD in the uFlags parameter, the cells will be centered around the specified CenterPt. This center point must be defined inside the bitmap or inside the region, if the bitmap has a region. 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.

An example of circular cell division can be seen below:

This is the original image:

The image below is the result of the following settings:

• uFlags = PIX_RAD | PIX_WPER | PIX_HPER | PIX_AVR
• uCellWidth = 90
• uCellHeight = 40

This indicates the circular cells are divided into 90 degree cell divisions and each cell has a radial length of 40 pixels. Each cell division is filled with the average value for that cell division.

The image below is the result of the following settings:

• uFlags = PIX_RAD | PIX_WFRQ | PIX_HFRQ | PIX_AVR
• uCellWidth = 90
• uCellHeight = 40

This indicates the circular cells are divided into 90 separate cell divisions around the center point and there are 40 cell divisions along the radius. Each cell division is filled with the average value for that cell division.

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.

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.

L_INT PixelateBitmapExample(L_VOID) 
{ 
   L_INT nRet; 
   BITMAPHANDLE LeadBitmap;   /* Bitmap handle for the image */ 
   POINT CenterPt;  
 
   /* Load a bitmap at its own bits per pixel  */ 
   nRet = L_LoadBitmap (MAKE_IMAGE_PATH(TEXT("sample5.cmp")), &LeadBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR, NULL, NULL); 
   if(nRet !=SUCCESS) 
      return nRet; 
   /* divide the image in to circular cells with angle length  = 5°, and radius = 10 */ 
   CenterPt.x  =  LeadBitmap.Width/2; 
   CenterPt.y  =  LeadBitmap. Height/2; 
   nRet = L_PixelateBitmap (&LeadBitmap, 5, 10, 100, CenterPt, PIX_AVR | PIX_RAD | PIX_WPER | PIX_HPER); 
   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; 
}