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December 1999

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1999.12.17 11:29 "TIFF previews in EPS files", by Flemming Bengtsson

1999.12.17 14:55 "Re: TIFF previews in EPS files", by Bjorn Brox

1999.12.17 15:54 "Re: TIFF previews in EPS files", by Dean Grimm

1999.12.17 15:54 "Re: TIFF previews in EPS files", by Dean Grimm

Hi Flemming,
  I use the following C++ code on Windows:

#define EPS_BUFFER_LEN			8192
#define EPS_THUMBTYPE_ERROR		-2
#define EPS_THUMBTYPE_NONE		-1
#define EPS_THUMBTYPE_TIFF		0
#define EPS_THUMBTYPE_META		1
const BYTE EPS_HDR_MAGIC_PS_ASCII[] = "%!";
const BYTE EPS_HDR_MAGIC_PS_WIN[] = {0xc5,0xd0,0xd3,0xc6};
typedef struct tagEPSHEADER {
	BYTE magic[4];
	DWORD offPS;
	DWORD lenPS;
	DWORD offMeta;
	DWORD lenMeta;
	DWORD offTiff;
	DWORD lenTiff;
	WORD checksum;
}EPSHEADER;

int ExtractEPSThumbnail(LPCTSTR pszEPSPath, LPCTSTR pszOutPath)
{
	int result = EPS_THUMBTYPE_NONE;
	HANDLE hf;

	// open the EPS file
	if ((hf=FOPEN(pszEPSPath)) != INVALID_HANDLE_VALUE)
	{
		EPSHEADER hdr;
		DWORD dwRead, dwOffset=0, dwLength=0;

		// read the header
		if (!ReadFile(hf, &hdr, sizeof(EPSHEADER), &dwRead, NULL)
			|| dwRead != sizeof(EPSHEADER))
		{
			CloseHandle(hf);
			return EPS_THUMBTYPE_NONE;
		}

		// check the type
		if (hdr.magic[0] == EPS_HDR_MAGIC_PS_ASCII[0]
			&& hdr.magic[1] == EPS_HDR_MAGIC_PS_ASCII[1])
		{
			result = EPS_THUMBTYPE_NONE;
		}
		else if (hdr.magic[0] == EPS_HDR_MAGIC_PS_WIN[0]
			&& hdr.magic[1] == EPS_HDR_MAGIC_PS_WIN[1]
			&& hdr.magic[2] == EPS_HDR_MAGIC_PS_WIN[2]
			&& hdr.magic[3] == EPS_HDR_MAGIC_PS_WIN[3])
		{
			// thumbnail is TIFF
			if (hdr.lenTiff>0)
			{
				result = EPS_THUMBTYPE_TIFF;
				dwOffset = hdr.offTiff;
				dwLength = hdr.lenTiff;
			}
			// thumbnail is metafile
			else if (hdr.lenMeta>0)
			{
				result = EPS_THUMBTYPE_META;
				dwOffset = hdr.offMeta;
				dwLength = hdr.lenMeta;
			}
			else
				result = EPS_THUMBTYPE_NONE;

			// extract the file
			if (dwLength > 0)
			{
				HANDLE hfOut;
				DWORD dwOut = 0, dwSize, dwWrite;
				
				// open the EPS file
				if ((hfOut=FOPEN(pszOutPath, GENERIC_WRITE,
CREATE_ALWAYS)) != INVALID_HANDLE_VALUE)
				{
					char buf[EPS_BUFFER_LEN];

					// seek to the thumbnail offset
					if (SetFilePointer(hf, dwOffset,
NULL, FILE_BEGIN) != 0xFFFFFFFF)
					{
						while (dwOut < dwLength)
						{
							// read, at most,
bufferlen bytes from input file
							dwSize =
min(EPS_BUFFER_LEN, dwLength-dwOut);
							if (!ReadFile(hf,
buf, dwSize, &dwRead, NULL)
								|| dwRead !=
dwSize)
							{
								result =
EPS_THUMBTYPE_ERROR;
								break;
							}

							// write bytes to
output file
							if
(!WriteFile(hfOut, buf, dwRead, &dwWrite, NULL)
								|| dwWrite
!= dwRead)
							{
								result =
EPS_THUMBTYPE_ERROR;
								break;
							}
							dwOut += dwSize;
						}
					}
					else
						result =
EPS_THUMBTYPE_ERROR;

					CloseHandle(hfOut);
				}
			}
		}

		CloseHandle(hf);
	}

	return result;
}

> -----Original Message-----
> From: Flemming Bengtsson [mailto:fb@adaptor-as.dk]
> Sent: Friday, December 17, 1999 3:30 AM
> To: tiff@olympiakos.com
> Subject: TIFF previews in EPS files
> 
> 
> Hi all,
> 
> Using Libtiff 3.5.3 on a PowerMac G4.
> 
> Does anyone know how to read TIFF previews in EPS files ?
> 
> Regards,
> -- 
> Flemming Bengtsson, Adaptor Digital Publishing A/S.
> 
>