L_Jp2ReadFramesMemory (original) (raw)

Summary

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

Syntax

#include "l_bitmap.h"

L_LTJP2_API L_INT EXT_FUNCTION L_Jp2ReadFramesMemory(hJp2, pBuffer, uBufferSize, pComposite, pFrames, uNumOfFrames, nBitsPerPixel, nOrder, pLoadOptions, pFileInfo, pReadCallBack, pUserData)

Parameters

L_HJP2 hJp2

JPEG 2000 engine handle that was created by the L_Jp2Create function.

L_UINT8 * pBuffer

Pointer to a JPEG 2000 file in memory.

L_SIZE_T uBufferSize

Size of JPEG 2000 file in bytes.

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:

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.

FILEREADCALLBACK 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 FILEREADCALLBACK function.

L_VOID * pUserData

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

Returns

Comments

L_Jp2ReadFramesMemory loads the specified frames bitmaps (Color, Opacity and Pre-multiplied opacity) stored in the specified JPEG 2000 file in memory. You must free this structure by calling the L_Jp2FreeComposite function. Also you must free structure bitmaps by calling the L_FreeBitmap function. All of the engines boxes will be reset.

Required DLLs and Libraries

• LTJP2
• LTIMGEFX
• LFJ2K
• 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.

See Also

Functions

• L_Jp2Read
• L_Jp2ReadList
• L_Jp2ReadComposite
• L_Jp2ReadFrames
• L_Jp2Save
• L_Jp2SaveList
• L_Jp2SaveComposite
• L_Jp2AppendFrames
• L_Jp2ReadMemory
• L_Jp2ReadListMemory
• L_Jp2ReadCompositeMemory
• L_Jp2SaveMemory
• L_Jp2SaveListMemory
• L_Jp2SaveCompositeMemory
• L_Jp2AppendFramesMemory

Topics

• Programming with JPEG 2000 Features
• Programming with JPX Features
• Raster Image Functions: Working with JPEG 2000
• Raster Image Functions: Working with JPX

Example

This example reads specific frame in JPEG 2000 file format

L_INT Jp2ReadFramesMemoryExample(pBITMAPHANDLE pBitmap, L_UINT8 * pFileBuffer, L_SIZE_T uFileSize) { L_HJP2 hEngine; L_INT nRet; L_JP2_JPXCOMPOSITE Composite = { 0 }; L_UINT32 puFrames[1] = { 0 }; Composite.uStructSize = sizeof(L_JP2_JPXCOMPOSITE); // Create JPEG 2000 engine handle hEngine = L_Jp2Create(); // Read a frame puFrames[0] = 0; nRet = L_Jp2ReadFramesMemory(hEngine, pFileBuffer, uFileSize, &Composite, puFrames, 1, 24, ORDER_BGR, NULL, NULL, NULL, NULL); if (nRet != SUCCESS) return nRet; *pBitmap = Composite.pBitmaps[0].ColorBitmap; // Free composite structure nRet = L_Jp2FreeComposite(hEngine, &Composite); if (nRet != SUCCESS) return nRet; // Destroy engine handle nRet = L_Jp2Destroy(hEngine); if (nRet != SUCCESS) return nRet; return SUCCESS; }