tif_dirinfo.c

一个国人自己实现图像库的程序（有参考价值）

#ifdef COLORIMETRY_SUPPORT
    { TIFFTAG_REFERENCEBLACKWHITE,6,6,TIFF_RATIONAL,	FIELD_REFBLACKWHITE,
      TRUE,	FALSE,	"ReferenceBlackWhite" },
/* XXX temporarily accept LONG for backwards compatibility */
    { TIFFTAG_REFERENCEBLACKWHITE,6,6,TIFF_LONG,	FIELD_REFBLACKWHITE,
      TRUE,	FALSE,	"ReferenceBlackWhite" },
#endif
/* begin SGI tags */
    { TIFFTAG_MATTEING,		 1, 1, TIFF_SHORT,	FIELD_EXTRASAMPLES,
      FALSE,	FALSE,	"Matteing" },
    { TIFFTAG_DATATYPE,		-2,-1, TIFF_SHORT,	FIELD_SAMPLEFORMAT,
      FALSE,	FALSE,	"DataType" },
    { TIFFTAG_IMAGEDEPTH,	 1, 1, TIFF_LONG,	FIELD_IMAGEDEPTH,
      FALSE,	FALSE,	"ImageDepth" },
    { TIFFTAG_IMAGEDEPTH,	 1, 1, TIFF_SHORT,	FIELD_IMAGEDEPTH,
      FALSE,	FALSE,	"ImageDepth" },
    { TIFFTAG_TILEDEPTH,	 1, 1, TIFF_LONG,	FIELD_TILEDEPTH,
      FALSE,	FALSE,	"TileDepth" },
    { TIFFTAG_TILEDEPTH,	 1, 1, TIFF_SHORT,	FIELD_TILEDEPTH,
      FALSE,	FALSE,	"TileDepth" },
/* end SGI tags */
/* begin Pixar tags */
    { TIFFTAG_PIXAR_IMAGEFULLWIDTH,  1, 1, TIFF_LONG,	FIELD_IMAGEFULLWIDTH,
      TRUE,	FALSE,	"ImageFullWidth" },
    { TIFFTAG_PIXAR_IMAGEFULLLENGTH, 1, 1, TIFF_LONG,	FIELD_IMAGEFULLLENGTH,
      TRUE,	FALSE,	"ImageFullLength" },
    { TIFFTAG_PIXAR_TEXTUREFORMAT,  -1,-1, TIFF_ASCII,	FIELD_TEXTUREFORMAT,
      TRUE,	FALSE,	"TextureFormat" },
    { TIFFTAG_PIXAR_WRAPMODES,	    -1,-1, TIFF_ASCII,	FIELD_WRAPMODES,
      TRUE,	FALSE,	"TextureWrapModes" },
    { TIFFTAG_PIXAR_FOVCOT,	     1, 1, TIFF_FLOAT,	FIELD_FOVCOT,
      TRUE,	FALSE,	"FieldOfViewCotan" },
    { TIFFTAG_PIXAR_MATRIX_WORLDTOSCREEN,	16,16,	TIFF_FLOAT,
      FIELD_MATRIX_WORLDTOSCREEN,	TRUE,	FALSE,	"MatrixWorldToScreen" },
    { TIFFTAG_PIXAR_MATRIX_WORLDTOCAMERA,	16,16,	TIFF_FLOAT,
       FIELD_MATRIX_WORLDTOCAMERA,	TRUE,	FALSE,	"MatrixWorldToCamera" },
    { TIFFTAG_COPYRIGHT,	-1,-1, TIFF_ASCII,	FIELD_COPYRIGHT,
      TRUE,	FALSE,	"Copyright" },
/* end Pixar tags */
#ifdef IPTC_SUPPORT
#ifdef PHOTOSHOP_SUPPORT
    { TIFFTAG_RICHTIFFIPTC, -1,-1, TIFF_LONG,   FIELD_RICHTIFFIPTC, 
      FALSE,    TRUE,   "RichTIFFIPTC" },
#else
    { TIFFTAG_RICHTIFFIPTC, -1,-3, TIFF_UNDEFINED, FIELD_RICHTIFFIPTC, 
      FALSE,    TRUE,   "RichTIFFIPTC" },
#endif
#endif
#ifdef PHOTOSHOP_SUPPORT
    { TIFFTAG_PHOTOSHOP,    -1,-3, TIFF_BYTE,   FIELD_PHOTOSHOP, 
      FALSE,    TRUE,   "Photoshop" },
#endif
#ifdef ICC_SUPPORT
    { TIFFTAG_ICCPROFILE,	-1,-3, TIFF_UNDEFINED,	FIELD_ICCPROFILE,
      FALSE,	TRUE,	"ICC Profile" },
#endif
    { TIFFTAG_STONITS,		 1, 1, TIFF_DOUBLE,	FIELD_STONITS,
      FALSE,	FALSE,	"StoNits" },
};
#define	N(a)	(sizeof (a) / sizeof (a[0]))

void
_TIFFSetupFieldInfo(TIFF* tif)
{
	if (tif->tif_fieldinfo) {
		_TIFFfree(tif->tif_fieldinfo);
		tif->tif_nfields = 0;
	}
	_TIFFMergeFieldInfo(tif, tiffFieldInfo, N(tiffFieldInfo));
}

static int
tagCompare(const void* a, const void* b)
{
	const TIFFFieldInfo* ta = *(const TIFFFieldInfo**) a;
	const TIFFFieldInfo* tb = *(const TIFFFieldInfo**) b;
	/* NB: be careful of return values for 16-bit platforms */
	if (ta->field_tag != tb->field_tag)
		return (ta->field_tag < tb->field_tag ? -1 : 1);
	else
		return (tb->field_type < ta->field_type ? -1 : 1);
}

void
_TIFFMergeFieldInfo(TIFF* tif, const TIFFFieldInfo info[], int n)
{
	TIFFFieldInfo** tp;
	int i;

	if (tif->tif_nfields > 0) {
		tif->tif_fieldinfo = (TIFFFieldInfo**)
		    _TIFFrealloc(tif->tif_fieldinfo,
			(tif->tif_nfields+n) * sizeof (TIFFFieldInfo*));
	} else {
		tif->tif_fieldinfo = (TIFFFieldInfo**)
		    _TIFFmalloc(n * sizeof (TIFFFieldInfo*));
	}
	tp = &tif->tif_fieldinfo[tif->tif_nfields];
	for (i = 0; i < n; i++)
		tp[i] = (TIFFFieldInfo*) &info[i];	/* XXX */
	/*
	 * NB: the core tags are presumed sorted correctly.
	 */
	if (tif->tif_nfields > 0)
		qsort(tif->tif_fieldinfo, (size_t) (tif->tif_nfields += n),
		    sizeof (TIFFFieldInfo*), tagCompare);
	else
		tif->tif_nfields += n;
}

void
_TIFFPrintFieldInfo(TIFF* tif, FILE* fd)
{
	int i;

	fprintf(fd, "%s: \n", tif->tif_name);
	for (i = 0; i < tif->tif_nfields; i++) {
		const TIFFFieldInfo* fip = tif->tif_fieldinfo[i];
		fprintf(fd, "field[%2d] %5lu, %2d, %2d, %d, %2d, %5s, %5s, %s\n"
			, i
			, (unsigned long) fip->field_tag
			, fip->field_readcount, fip->field_writecount
			, fip->field_type
			, fip->field_bit
			, fip->field_oktochange ? "TRUE" : "FALSE"
			, fip->field_passcount ? "TRUE" : "FALSE"
			, fip->field_name
		);
	}
}

const int tiffDataWidth[] = {
    1,	/* nothing */
    1,	/* TIFF_BYTE */
    1,	/* TIFF_ASCII */
    2,	/* TIFF_SHORT */
    4,	/* TIFF_LONG */
    8,	/* TIFF_RATIONAL */
    1,	/* TIFF_SBYTE */
    1,	/* TIFF_UNDEFINED */
    2,	/* TIFF_SSHORT */
    4,	/* TIFF_SLONG */
    8,	/* TIFF_SRATIONAL */
    4,	/* TIFF_FLOAT */
    8,	/* TIFF_DOUBLE */
};

/*
 * Return nearest TIFFDataType to the sample type of an image.
 */
TIFFDataType
_TIFFSampleToTagType(TIFF* tif)
{
	int bps = (int) TIFFhowmany(tif->tif_dir.td_bitspersample, 8);

	switch (tif->tif_dir.td_sampleformat) {
	case SAMPLEFORMAT_IEEEFP:
		return (bps == 4 ? TIFF_FLOAT : TIFF_DOUBLE);
	case SAMPLEFORMAT_INT:
		return (bps <= 1 ? TIFF_SBYTE :
		    bps <= 2 ? TIFF_SSHORT : TIFF_SLONG);
	case SAMPLEFORMAT_UINT:
		return (bps <= 1 ? TIFF_BYTE :
		    bps <= 2 ? TIFF_SHORT : TIFF_LONG);
	case SAMPLEFORMAT_VOID:
		return (TIFF_UNDEFINED);
	}
	/*NOTREACHED*/
	return (TIFF_UNDEFINED);
}

const TIFFFieldInfo*
_TIFFFindFieldInfo(TIFF* tif, ttag_t tag, TIFFDataType dt)
{
	static const TIFFFieldInfo *last = NULL;
	int i, n;

	if (last && last->field_tag == tag &&
	    (dt == TIFF_ANY || dt == last->field_type))
		return (last);
	/* NB: if table gets big, use sorted search (e.g. binary search) */
	for (i = 0, n = tif->tif_nfields; i < n; i++) {
		const TIFFFieldInfo* fip = tif->tif_fieldinfo[i];
		if (fip->field_tag == tag &&
		    (dt == TIFF_ANY || fip->field_type == dt))
			return (last = fip);
	}
	return ((const TIFFFieldInfo *)0);
}

#include <assert.h>
#include <stdio.h>

const TIFFFieldInfo*
_TIFFFieldWithTag(TIFF* tif, ttag_t tag)
{
	const TIFFFieldInfo* fip = _TIFFFindFieldInfo(tif, tag, TIFF_ANY);
	if (!fip) {
		TIFFError("TIFFFieldWithTag",
		    "Internal error, unknown tag 0x%x", (u_int) tag);
		assert(fip != NULL);
		/*NOTREACHED*/
	}
	return (fip);
}