tif_dirread.c

一个国人自己实现图像库的程序（有参考价值）

/* $Header: /cvsroot/osrs/libtiff/libtiff/tif_dirread.c,v 1.6 2000/04/21 21:45:33 warmerda Exp $ */

/*
 * Copyright (c) 1988-1997 Sam Leffler
 * Copyright (c) 1991-1997 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and 
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Sam Leffler and Silicon Graphics.
 * 
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
 * 
 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
 * OF THIS SOFTWARE.
 */

/*
 * TIFF Library.
 *
 * Directory Read Support Routines.
 */
#include "tiffiop.h"

#define	IGNORE	0		/* tag placeholder used below */

#if HAVE_IEEEFP
#define	TIFFCvtIEEEFloatToNative(tif, n, fp)
#define	TIFFCvtIEEEDoubleToNative(tif, n, dp)
#else
extern	void TIFFCvtIEEEFloatToNative(TIFF*, uint32, float*);
extern	void TIFFCvtIEEEDoubleToNative(TIFF*, uint32, double*);
#endif

static	void EstimateStripByteCounts(TIFF*, TIFFDirEntry*, uint16);
static	void MissingRequired(TIFF*, const char*);
static	int CheckDirCount(TIFF*, TIFFDirEntry*, uint32);
static	tsize_t TIFFFetchData(TIFF*, TIFFDirEntry*, char*);
static	tsize_t TIFFFetchString(TIFF*, TIFFDirEntry*, char*);
static	float TIFFFetchRational(TIFF*, TIFFDirEntry*);
static	int TIFFFetchNormalTag(TIFF*, TIFFDirEntry*);
static	int TIFFFetchPerSampleShorts(TIFF*, TIFFDirEntry*, int*);
static	int TIFFFetchPerSampleAnys(TIFF*, TIFFDirEntry*, double*);
static	int TIFFFetchShortArray(TIFF*, TIFFDirEntry*, uint16*);
static	int TIFFFetchStripThing(TIFF*, TIFFDirEntry*, long, uint32**);
static	int TIFFFetchExtraSamples(TIFF*, TIFFDirEntry*);
static	int TIFFFetchRefBlackWhite(TIFF*, TIFFDirEntry*);
static	float TIFFFetchFloat(TIFF*, TIFFDirEntry*);
static	int TIFFFetchFloatArray(TIFF*, TIFFDirEntry*, float*);
static	int TIFFFetchDoubleArray(TIFF*, TIFFDirEntry*, double*);
static	int TIFFFetchAnyArray(TIFF*, TIFFDirEntry*, double*);
static	int TIFFFetchShortPair(TIFF*, TIFFDirEntry*);
static	void ChopUpSingleUncompressedStrip(TIFF*);

static char *
CheckMalloc(TIFF* tif, tsize_t n, const char* what)
{
	char *cp = (char*)_TIFFmalloc(n);
	if (cp == NULL)
		TIFFError(tif->tif_name, "No space %s", what);
	return (cp);
}

/*
 * Read the next TIFF directory from a file
 * and convert it to the internal format.
 * We read directories sequentially.
 */
int
TIFFReadDirectory(TIFF* tif)
{
	register TIFFDirEntry* dp;
	register int n;
	register TIFFDirectory* td;
	TIFFDirEntry* dir;
	int iv;
	long v;
	double dv;
	const TIFFFieldInfo* fip;
	int fix;
	uint16 dircount;
	toff_t nextdiroff;
	char* cp;
	int diroutoforderwarning = 0;

	tif->tif_diroff = tif->tif_nextdiroff;
	if (tif->tif_diroff == 0)		/* no more directories */
		return (0);
	/*
	 * Cleanup any previous compression state.
	 */
	(*tif->tif_cleanup)(tif);
	tif->tif_curdir++;
	nextdiroff = 0;
	if (!isMapped(tif)) {
		if (!SeekOK(tif, tif->tif_diroff)) {
			TIFFError(tif->tif_name,
			    "Seek error accessing TIFF directory");
			return (0);
		}
		if (!ReadOK(tif, &dircount, sizeof (uint16))) {
			TIFFError(tif->tif_name,
			    "Can not read TIFF directory count");
			return (0);
		}
		if (tif->tif_flags & TIFF_SWAB)
			TIFFSwabShort(&dircount);
		dir = (TIFFDirEntry *)CheckMalloc(tif,
		    dircount * sizeof (TIFFDirEntry), "to read TIFF directory");
		if (dir == NULL)
			return (0);
		if (!ReadOK(tif, dir, dircount*sizeof (TIFFDirEntry))) {
			TIFFError(tif->tif_name, "Can not read TIFF directory");
			goto bad;
		}
		/*
		 * Read offset to next directory for sequential scans.
		 */
		(void) ReadOK(tif, &nextdiroff, sizeof (uint32));
	} else {
		toff_t off = tif->tif_diroff;

		if (off + sizeof (uint16) > tif->tif_size) {
			TIFFError(tif->tif_name,
			    "Can not read TIFF directory count");
			return (0);
		} else
			_TIFFmemcpy(&dircount, tif->tif_base + off, sizeof (uint16));
		off += sizeof (uint16);
		if (tif->tif_flags & TIFF_SWAB)
			TIFFSwabShort(&dircount);
		dir = (TIFFDirEntry *)CheckMalloc(tif,
		    dircount * sizeof (TIFFDirEntry), "to read TIFF directory");
		if (dir == NULL)
			return (0);
		if (off + dircount*sizeof (TIFFDirEntry) > tif->tif_size) {
			TIFFError(tif->tif_name, "Can not read TIFF directory");
			goto bad;
		} else
			_TIFFmemcpy(dir, tif->tif_base + off,
			    dircount*sizeof (TIFFDirEntry));
		off += dircount* sizeof (TIFFDirEntry);
		if (off + sizeof (uint32) <= tif->tif_size)
			_TIFFmemcpy(&nextdiroff, tif->tif_base+off, sizeof (uint32));
	}
	if (tif->tif_flags & TIFF_SWAB)
		TIFFSwabLong(&nextdiroff);
	tif->tif_nextdiroff = nextdiroff;

	tif->tif_flags &= ~TIFF_BEENWRITING;	/* reset before new dir */
	/*
	 * Setup default value and then make a pass over
	 * the fields to check type and tag information,
	 * and to extract info required to size data
	 * structures.  A second pass is made afterwards
	 * to read in everthing not taken in the first pass.
	 */
	td = &tif->tif_dir;
	/* free any old stuff and reinit */
	TIFFFreeDirectory(tif);
	TIFFDefaultDirectory(tif);
	/*
	 * Electronic Arts writes gray-scale TIFF files
	 * without a PlanarConfiguration directory entry.
	 * Thus we setup a default value here, even though
	 * the TIFF spec says there is no default value.
	 */
	TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);

	/*
	 * Sigh, we must make a separate pass through the
	 * directory for the following reason:
	 *
	 * We must process the Compression tag in the first pass
	 * in order to merge in codec-private tag definitions (otherwise
	 * we may get complaints about unknown tags).  However, the
	 * Compression tag may be dependent on the SamplesPerPixel
	 * tag value because older TIFF specs permited Compression
	 * to be written as a SamplesPerPixel-count tag entry.
	 * Thus if we don't first figure out the correct SamplesPerPixel
	 * tag value then we may end up ignoring the Compression tag
	 * value because it has an incorrect count value (if the
	 * true value of SamplesPerPixel is not 1).
	 *
	 * It sure would have been nice if Aldus had really thought
	 * this stuff through carefully.
	 */ 
	for (dp = dir, n = dircount; n > 0; n--, dp++) {
		if (tif->tif_flags & TIFF_SWAB) {
			TIFFSwabArrayOfShort(&dp->tdir_tag, 2);
			TIFFSwabArrayOfLong(&dp->tdir_count, 2);
		}
		if (dp->tdir_tag == TIFFTAG_SAMPLESPERPIXEL) {
			if (!TIFFFetchNormalTag(tif, dp))
				goto bad;
			dp->tdir_tag = IGNORE;
		}
	}
	/*
	 * First real pass over the directory.
	 */
	fix = 0;
	for (dp = dir, n = dircount; n > 0; n--, dp++) {

                /*
                 * Find the field information entry for this tag.
		 * Added check for tags to ignore ... [BFC]
                 */
		if( TIFFReassignTagToIgnore(TIS_EXTRACT, dp->tdir_tag) )
                    dp->tdir_tag = IGNORE;

		if (dp->tdir_tag == IGNORE)
                    continue;
                
		/*
		 * Silicon Beach (at least) writes unordered
		 * directory tags (violating the spec).  Handle
		 * it here, but be obnoxious (maybe they'll fix it?).
		 */
		if (dp->tdir_tag < tif->tif_fieldinfo[fix]->field_tag) {
			if (!diroutoforderwarning) {
				TIFFWarning(tif->tif_name,
	"invalid TIFF directory; tags are not sorted in ascending order");
				diroutoforderwarning = 1;
			}
			fix = 0;			/* O(n^2) */
		}
		while (fix < tif->tif_nfields &&
		    tif->tif_fieldinfo[fix]->field_tag < dp->tdir_tag)
			fix++;
		if (fix == tif->tif_nfields ||
		    tif->tif_fieldinfo[fix]->field_tag != dp->tdir_tag) {
			TIFFWarning(tif->tif_name,
			    "unknown field with tag %d (0x%x) ignored",
			    dp->tdir_tag,  dp->tdir_tag);
			dp->tdir_tag = IGNORE;
			fix = 0;			/* restart search */
			continue;
		}
		/*
		 * Null out old tags that we ignore.
		 */
		if (tif->tif_fieldinfo[fix]->field_bit == FIELD_IGNORE) {
	ignore:
			dp->tdir_tag = IGNORE;
			continue;
		}
		/*
		 * Check data type.
		 */
		fip = tif->tif_fieldinfo[fix];
		while (dp->tdir_type != (u_short) fip->field_type) {
			if (fip->field_type == TIFF_ANY)	/* wildcard */
				break;
			fip++, fix++;
			if (fix == tif->tif_nfields ||
			    fip->field_tag != dp->tdir_tag) {
				TIFFWarning(tif->tif_name,
				   "wrong data type %d for \"%s\"; tag ignored",
				    dp->tdir_type, fip[-1].field_name);
				goto ignore;
			}
		}
		/*
		 * Check count if known in advance.
		 */
		if (fip->field_readcount != TIFF_VARIABLE) {
			uint32 expected = (fip->field_readcount == TIFF_SPP) ?
			    (uint32) td->td_samplesperpixel :
			    (uint32) fip->field_readcount;
			if (!CheckDirCount(tif, dp, expected))
				goto ignore;
		}

		switch (dp->tdir_tag) {
		case TIFFTAG_COMPRESSION:
			/*
			 * The 5.0 spec says the Compression tag has
			 * one value, while earlier specs say it has
			 * one value per sample.  Because of this, we
			 * accept the tag if one value is supplied.
			 */
			if (dp->tdir_count == 1) {
				v = TIFFExtractData(tif,
				    dp->tdir_type, dp->tdir_offset);
				if (!TIFFSetField(tif, dp->tdir_tag, (int)v))
					goto bad;
				break;
			}
			if (!TIFFFetchPerSampleShorts(tif, dp, &iv) ||
			    !TIFFSetField(tif, dp->tdir_tag, iv))
				goto bad;
			dp->tdir_tag = IGNORE;
			break;
		case TIFFTAG_STRIPOFFSETS:
		case TIFFTAG_STRIPBYTECOUNTS:
		case TIFFTAG_TILEOFFSETS:
		case TIFFTAG_TILEBYTECOUNTS:
			TIFFSetFieldBit(tif, fip->field_bit);
			break;
		case TIFFTAG_IMAGEWIDTH:
		case TIFFTAG_IMAGELENGTH:
		case TIFFTAG_IMAGEDEPTH:
		case TIFFTAG_TILELENGTH:
		case TIFFTAG_TILEWIDTH:
		case TIFFTAG_TILEDEPTH:
		case TIFFTAG_PLANARCONFIG:
		case TIFFTAG_ROWSPERSTRIP:
			if (!TIFFFetchNormalTag(tif, dp))
				goto bad;
			dp->tdir_tag = IGNORE;
			break;
		case TIFFTAG_EXTRASAMPLES:
			(void) TIFFFetchExtraSamples(tif, dp);
			dp->tdir_tag = IGNORE;
			break;
		}
	}

	/*
	 * Allocate directory structure and setup defaults.
	 */
	if (!TIFFFieldSet(tif, FIELD_IMAGEDIMENSIONS)) {
		MissingRequired(tif, "ImageLength");
		goto bad;
	}
	if (!TIFFFieldSet(tif, FIELD_PLANARCONFIG)) {
		MissingRequired(tif, "PlanarConfiguration");
		goto bad;
	}
	/* 
 	 * Setup appropriate structures (by strip or by tile)
	 */
	if (!TIFFFieldSet(tif, FIELD_TILEDIMENSIONS)) {
		td->td_nstrips = TIFFNumberOfStrips(tif);
		td->td_tilewidth = td->td_imagewidth;
		td->td_tilelength = td->td_rowsperstrip;
		td->td_tiledepth = td->td_imagedepth;
		tif->tif_flags &= ~TIFF_ISTILED;
	} else {
		td->td_nstrips = TIFFNumberOfTiles(tif);
		tif->tif_flags |= TIFF_ISTILED;
	}
	td->td_stripsperimage = td->td_nstrips;
	if (td->td_planarconfig == PLANARCONFIG_SEPARATE)
		td->td_stripsperimage /= td->td_samplesperpixel;
	if (!TIFFFieldSet(tif, FIELD_STRIPOFFSETS)) {
		MissingRequired(tif,
		    isTiled(tif) ? "TileOffsets" : "StripOffsets");
		goto bad;
	}

	/*
	 * Second pass: extract other information.
	 */
	for (dp = dir, n = dircount; n > 0; n--, dp++) {
		if (dp->tdir_tag == IGNORE)
			continue;
		switch (dp->tdir_tag) {
		case TIFFTAG_MINSAMPLEVALUE:
		case TIFFTAG_MAXSAMPLEVALUE:
		case TIFFTAG_BITSPERSAMPLE:
			/*
			 * The 5.0 spec says the Compression tag has
			 * one value, while earlier specs say it has
			 * one value per sample.  Because of this, we
			 * accept the tag if one value is supplied.
			 *
			 * The MinSampleValue, MaxSampleValue and
			 * BitsPerSample tags are supposed to be written
			 * as one value/sample, but some vendors incorrectly
			 * write one value only -- so we accept that
			 * as well (yech).
			 */
			if (dp->tdir_count == 1) {
				v = TIFFExtractData(tif,
				    dp->tdir_type, dp->tdir_offset);
				if (!TIFFSetField(tif, dp->tdir_tag, (int)v))
					goto bad;
				break;
			}
			/* fall thru... */
		case TIFFTAG_DATATYPE:
		case TIFFTAG_SAMPLEFORMAT:
			if (!TIFFFetchPerSampleShorts(tif, dp, &iv) ||
			    !TIFFSetField(tif, dp->tdir_tag, iv))
				goto bad;
			break;
		case TIFFTAG_SMINSAMPLEVALUE:
		case TIFFTAG_SMAXSAMPLEVALUE:
			if (!TIFFFetchPerSampleAnys(tif, dp, &dv) ||
			    !TIFFSetField(tif, dp->tdir_tag, dv))
				goto bad;
			break;
		case TIFFTAG_STRIPOFFSETS:
		case TIFFTAG_TILEOFFSETS:
			if (!TIFFFetchStripThing(tif, dp,
			    td->td_nstrips, &td->td_stripoffset))
				goto bad;
			break;
		case TIFFTAG_STRIPBYTECOUNTS:
		case TIFFTAG_TILEBYTECOUNTS:
			if (!TIFFFetchStripThing(tif, dp,
			    td->td_nstrips, &td->td_stripbytecount))
				goto bad;
			break;
		case TIFFTAG_COLORMAP:
		case TIFFTAG_TRANSFERFUNCTION:
			/*
			 * TransferFunction can have either 1x or 3x data
			 * values; Colormap can have only 3x items.
			 */
			v = 1L<<td->td_bitspersample;
			if (dp->tdir_tag == TIFFTAG_COLORMAP ||
			    dp->tdir_count != (uint32) v) {
				if (!CheckDirCount(tif, dp, (uint32)(3*v)))
					break;
			}
			v *= sizeof (uint16);
			cp = CheckMalloc(tif, dp->tdir_count * sizeof (uint16),
			    "to read \"TransferFunction\" tag");
			if (cp != NULL) {
				if (TIFFFetchData(tif, dp, cp)) {
					/*
					 * This deals with there being only
					 * one array to apply to all samples.
					 */
					uint32 c =
					    (uint32)1 << td->td_bitspersample;
					if (dp->tdir_count == c)
						v = 0;
					TIFFSetField(tif, dp->tdir_tag,
					    cp, cp+v, cp+2*v);
				}
				_TIFFfree(cp);
			}
			break;
		case TIFFTAG_PAGENUMBER:
		case TIFFTAG_HALFTONEHINTS:
		case TIFFTAG_YCBCRSUBSAMPLING:
		case TIFFTAG_DOTRANGE:
			(void) TIFFFetchShortPair(tif, dp);
			break;
#ifdef COLORIMETRY_SUPPORT
		case TIFFTAG_REFERENCEBLACKWHITE:
			(void) TIFFFetchRefBlackWhite(tif, dp);
			break;
#endif
/* BEGIN REV 4.0 COMPATIBILITY */
		case TIFFTAG_OSUBFILETYPE: