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LJp2FileFormat::ExtractFrames

Summary

Extracts the frames that are specified by puFrames from the input file, and saves them into a new JPEG 2000 file contains only the extracted frames headers and codestreams directly not through decompressing/compressing process.

Syntax

#include "ltwrappr.h"

L_INT LJp2FileFormat::ExtractFrames(pInFileName, pOutFileName, puFrames, uNumOfFrames)

Parameters

L_TCHAR * pInFileName

Character string that contains the name of the JPEG 2000 file to extract frames from it.

L_TCHAR * pOutFileName

Character string that contains the name of the new JPEG 2000 file that contains the extracted frames only.

L_UINT32 * puFrames

Array of unsigned integers specifies the indices of the frames to be extracted from the input JPEG 2000 file. All indices shall be 0-based. If any frames index is out the frames number the function will return ERROR_INV_PARAMETER.

L_UINT32 uNumOfFrames

Number of frames to be extracted. This field specifies the size of puFrames array.

Returns

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

Comments

LJp2FileFormat::ExtractFrames extracts the specified frames from the input file and save them into a new JPEG 2000 file contains only the extracted frames headers and codestreams directly not through decompressing/compressing process so it saves processor time and memory. This function is very suitable to server application where multiple clients request specific frames of a JPEG 2000 file so instead of decompressing then compressing the frames this function copies only the needed frames data to generate them and saves the data into a new JPEG 2000 file.

Required DLLs and Libraries

LTJP2
LFJ2K
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.

Example

This example extracts a frame from JPX file.

L_INT LJp2FileFormat__ExtractFramesExample(L_VOID) 
{ 
   LJp2FileFormat Engine; 
   L_JP2_FILEINFO Jp2FileInfo; 
   L_UINT32 puFrames[1]; 
   L_INT nRet = 0; 
 
 
   Jp2FileInfo.uStructSize = sizeof(L_JP2_FILEINFO); 
   Engine.GetFileInfo(MAKE_IMAGE_PATH(TEXT("image1.jpx")),&Jp2FileInfo); 
   if(Jp2FileInfo.MPEG7.uNumOfBoxes == 0) 
      return 0; 
 
   if(Jp2FileInfo.uNumOfFrames < 2) 
      return 0; 
 
   if(Jp2FileInfo.DataRef.uNumOfBoxes) 
      return 0; 
 
   /*Extract the second frame*/ 
   puFrames[0] = 1; 
 
   nRet = Engine.ExtractFrames(MAKE_IMAGE_PATH(TEXT("image1.jpx")), MAKE_IMAGE_PATH(TEXT("Test.jpx")), puFrames, 1); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   /*Free File Info structure*/ 
   nRet = Engine.FreeFileInfo( &Jp2FileInfo); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   return SUCCESS; 
}