LJp2FileFormat::ReadFrames

Summary

Loads the specified frames bitmaps (Color, Opacity and Pre-multiplied opacity) stored in the specified JPEG 2000 file.

Syntax

#include "ltwrappr.h"

L_INT LJp2FileFormat::ReadFrames(pszFile, pComposite, pFrames, uNumOfFrames, nBitsPerPixel, nOrder, pLoadOptions, pFileInfo, pReadCallBack, pUserData)

Parameters

L_TCHAR * pszFile

Character string that contains the name of the JPEG 2000 file.

pL_JP2_JPXCOMPOSITE pComposite

Pointer to the L_JP2_JPXCOMPOSITE structure that references L_JP2_JPXBITMAPS bitmaps to be filled with image data.

L_UINT32 * pFrames

Frames indices. An array of unsigned integers specifies the indices of the frames to be loaded from the file.

L_UINT32 uNumOfFrames

Number of frames to be loaded. This value specifies the size of pFrames.

L_INT nBitsPerPixel

Resulting bitmap pixel depth. If zero [0], the bitmap will have the original files pixel depth (do not convert).

L_INT nOrder

The desired color order. Possible values are:

Value	Meaning
ORDER_RGB	[0] Read-green-blue order.
ORDER_BGR	[1] Blue green-red order.
ORDER_GRAY	[2] 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in Document/Medical imaging products only.
0	The data is 8 bits per pixel or less.
ORDER_RGBORGRAY	[3] Load the image as red, green, blue, OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in Document/Medical imaging products only.
ORDER_BGRORGRAY	[4] Load the image as blue, green, red, OR as a 12 or 16-bit grayscale image. 12 and 16-bit grayscale images are supported in Document/Medical imaging products only.
ORDER_ROMM	[5] ROMM order. ROMM only supports 24 and 48-bit images.
ORDER_BGRORGRAYORROMM	[6] Load the image as blue, green, red, OR as a 12 or 16-bit grayscale image OR as ROMM. 12 and 16-bit grayscale images are supported in Document/Medical imaging products only.

pLOADFILEOPTION pLoadOptions

Pointer to optional extended load options. Pass NULL to use the default load options.

pFILEINFO pFileInfo

Pointer to a FILEINFO structure. If nothing is known about the file pass NULL.

LFile::LoadFileCallBack pReadCallBack

Optional callback function for additional processing.

If you do not provide a callback function, pass NULL.

If you do provide a callback function, use the function pointer as the value of this parameter.

The callback function must adhere to the function prototype described in the LFile::LoadFileCallBack function.

L_VOID * pUserData

Void pointer that you can use to pass one or more additional parameters used by the callback function.

Returns

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

Comments

LJp2FileFormat::ReadFrames loads the specified frames bitmaps (Color, Opacity and Pre-multiplied opacity) stored in the specified JPEG 2000 file. You must free this structure by calling the LJp2FileFormat::FreeComposite function. Also you must free structure bitmaps by calling the LBitmapBase::Free function. All of the engines boxes will be reset.

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 reads specific frame in JPEG 2000 file format

L_INT LJp2FileFormat__ReadFramesExample() 
{ 
   LJp2FileFormat Engine; 
   L_INT  nRet; 
   L_JP2_JPXCOMPOSITE Composite = {0};  
   L_UINT32 puFrames[1] = {0}; 
 
   Composite.uStructSize = sizeof(L_JP2_JPXCOMPOSITE); 
 
   /*Read a frame*/ 
   puFrames[0] = 0; 
   nRet = Engine.ReadFrames(MAKE_IMAGE_PATH(TEXT("image1.jpx")),&Composite,puFrames,1,24,ORDER_BGR,NULL,NULL,NULL, NULL); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   /*you may use the bitmaps*/ 
   //Composite.pBitmaps[0].ColorBitmap; 
 
   for (L_UINT32 index=0;index<Composite.uNumOfBitmaps; index++) 
   { 
      L_FreeBitmap(&Composite.pBitmaps[index].ColorBitmap); 
   } 
 
   /*Free composite structure*/ 
   Engine.FreeComposite( &Composite); 
 
   return SUCCESS; 
}