LFileSettings::SetSaveResolution

#include "ltwrappr.h"

static L_INT LFileSettings::SetSaveResolution(uCount, pResolutions)

L_UINT uCount;	/* number of resolutions to be saved in a file */
pDIMENSION pResolutions;	/* pointer to the array which holds the resolutions to be saved */

Sets resolutions for the next save operation.

Parameter	Description
uCount	Specifies the number of resolutions to be saved in a file. Or, specify 0 to save only the actual size of the image as a single dimension in the file.
pResolutions	Pointer to the array of DIMENSION structures which hold the resolutions to be saved.

Returns

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

Comments

Currently, this function only works with the JBIG format.

A JBIG, FlashPix or PhotoCD file can contain more than one copy of the same image, each at a different physical resolution (width and height in pixels).

For JBIG files, uCount refers to the number of resolution layers to be saved in the file. The maximum number of resolutions that can be saved is 29.

For a JBIG file, the values of different resolutions are implied because the dimensions of each resolution layer are half the dimensions of the one directly above it.

pResolutions[0] is used to determine the highest resolution layer which will be saved in a file. You can fill pResolutions[0] with an actual width and height, or you can fill either the width or height with a valid value, and specify 0 for the other dimension to allow LEADTOOLS to calculate that dimension based on the image's aspect ratio during the next save operation. Note that for JBIG, all the values set in pResolutions are stored, but only pResolutions[0] is used during an actual file save process.

Ex.

uCount = 3
pResolution[0].nWidth = 800
pResolution[0].nHeight = 0

If you then save an image that is 1600 x 1200, the resolutions that are stored in the file would be:

800 x 600

400 x 300

200 x 150

Required DLLs and Libraries

LTFIL

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

See Also

Functions:	Class Members
Topics:	Raster Image Functions: Saving Files
	Raster Image Functions: Getting and Setting File Information
	Implementing JBIG Features

Example

This example saves the same image in three different resolutions and in three different files.

L_INT LFileSettings__SetSaveResolutionExample()
{
   L_INT nRet;
   LFileSettings FileSet;
   pDIMENSION pRes;
   HGLOBAL hRes;
   L_INT x;
   hRes = GlobalAlloc(GMEM_MOVEABLE, sizeof(DIMENSION)* 4);
   pRes = (pDIMENSION)GlobalLock( hRes );
   /* store four resolution layers */
   for(x=0;x<4;x++)
   {
      pRes[x].nWidth  = (int)(1600/(x+1));
      pRes[x].nHeight = (int)( 800/(x+1));
   }
   nRet = FileSet.SetSaveResolution(4, pRes);
   if(nRet != SUCCESS)
      return nRet;
   GlobalUnlock (hRes);
   GlobalFree (hRes);
   return SUCCESS;
}