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Re: How to load/decompress a file into your own buffer Started by Travis at 05-18-2006 15:34. Topic has 2 replies. LEAD Support Fo... » Developer » Image Compressi... » Re: How to load/decompress a file into your own buffer

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05-18-2006, 15:34 Travis Joined on 07-07-2003 In house Posts 286 How to load/decompress a file into your own buffer Attachment: API - V14 - Load Image into user buffer.zip Attached is an example (written in VC 6.0 using MFC and using LEAD's API functions) that shows how to load an image into a buffer the developer allocates.  The bulk of the code is below: 1. When you call L_CreateBitmap, the last parameter must be the EXACT required size.  L_UINT32 GetRequiredSize(L_INT nWidth, L_INT nHeight, L_INT nBitsPerPixel) {     L_INT nSize = 0;    BITMAPHANDLE TempBitmap;    memset(&TempBitmap, 0, sizeof(TempBitmap));       nRet = L_InitBitmap(&TempBitmap, sizeof(TempBitmap), nWidth, nHeight, nBitsPerPixel);    if (nRet == SUCCESS)    {       nSize =  TempBitmap.Size;    }    return nSize; }  2. When calling LoadFile, you must pass the flags (LOADFILE_STORE | LOADFILE_NOINITBITMAP) like so:   BOOL MyLoadBitmap(L_CHAR *pszFile, pBITMAPHANDLE pBitmap, L_INT nWidth, L_INT nHeight, L_INT nBitsPerPixel) {    L_INT nRet;     L_INT nSize = 0;    L_UCHAR *pData = NULL;       if (!pBitmap)       return FALSE;       nSize = GetRequiredSize(nWidth,nHeight,nBitsPerPixel);    if (nSize == 0)       return FALSE;       pData = (L_UCHAR *)malloc(nSize);    if (!pData)       return FALSE;       nRet = L_CreateBitmap(pBitmap, sizeof(BITMAPHANDLE), TYPE_USER, nWidth, nHeight, nBitsPerPixel, ORDER_BGR, 0, BOTTOM_LEFT, pData, nSize);    if (nRet != SUCCESS)    {       free(pData);       return FALSE;    }       nRet = L_LoadFile(pszFile, pBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR,       LOADFILE_STORE | LOADFILE_NOINITBITMAP, NULL, NULL, NULL, NULL);       return (nRet == SUCCESS); } Travis Montgomery LEAD Technical Support    Report

05-21-2008, 18:24 DCurtis Joined on 02-09-2007 Posts 18 Re: How to load/decompress a file into your own buffer Attachment: ViewPerspective.jpg That seems to work fine most of the time, but there are cases when it doesn't work. How can I make this code work when there is a different view perspective set in the file that I'm loading? For example, the attached file has a view perspective of RIGHT_TOP which makes the L_LoadFile call fail. I need to be able to handle this case. What should I do?    Report

05-22-2008, 15:41 GregR Joined on 05-31-2006 In House Posts 1,607 Re: How to load/decompress a file into your own buffer You should set the ELO_IGNOREVIEWPERSPECTIVE flag in the LOADFILEOPTION.Flags property.  If you use this for both the call to L_FileInfo and L_LoadFile, then it should work.  Though not necessary for L_LoadFile to return SUCCESS, I would also suggest using the view perspective reported by L_FileInfo as well.  Here's the modified code snippet: void CTutorDlg::OnLoad() {     L_INT nRet;    L_INT nSize = 0;    L_UCHAR *pData = NULL;     BITMAPHANDLE Bitmap;     FILEINFO fi;     L_INT nWidth, nHeight, nBitsPerPixel, nViewPerspective;     LOADFILEOPTION lfo;     L_GetDefaultLoadFileOption(&lfo, sizeof(LOADFILEOPTION));     lfo.Flags = ELO_IGNOREVIEWPERSPECTIVE;         nRet = L_FileInfo("Test.jpg", &fi, sizeof(FILEINFO), 0, &lfo);     nWidth = fi.Width;     nHeight = fi.Height;     nBitsPerPixel = fi.BitsPerPixel;     nViewPerspective = fi.ViewPerspective;          nSize = GetRequiredSize(nWidth,nHeight,nBitsPerPixel);    if (nSize == 0)       return;       pData = (L_UCHAR *)malloc(nSize);    if (!pData)       return;       nRet = L_CreateBitmap(&Bitmap, sizeof(BITMAPHANDLE), TYPE_USER, nWidth, nHeight, nBitsPerPixel, ORDER_BGR, 0, nViewPerspective, pData, nSize);    if (nRet != SUCCESS)    {       free(pData);       return;    }       nRet = L_LoadFile("Test.jpg", &Bitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGR,       LOADFILE_STORE | LOADFILE_NOINITBITMAP, NULL, NULL, &lfo, NULL);       return; } Greg Ross LEADTOOLS Technical Support    Report

LEAD Support Fo... » Developer » Image Compressi... » Re: How to load/decompress a file into your own buffer

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