text: /* $Id: tif_luv.c,v 1.35 2011-04-02 20:54:09 bfriesen Exp $ */
  
  /*
   * Copyright (c) 1997 Greg Ward Larson
   * Copyright (c) 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, Greg Larson 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, Greg Larson 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, GREG LARSON 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.
   */
  
  #include "tiffiop.h"
  #ifdef LOGLUV_SUPPORT
  
  /*
   * TIFF Library.
   * LogLuv compression support for high dynamic range images.
   *
   * Contributed by Greg Larson.
   *
   * LogLuv image support uses the TIFF library to store 16 or 10-bit
   * log luminance values with 8 bits each of u and v or a 14-bit index.
   *
   * The codec can take as input and produce as output 32-bit IEEE float values 
   * as well as 16-bit integer values.  A 16-bit luminance is interpreted
   * as a sign bit followed by a 15-bit integer that is converted
   * to and from a linear magnitude using the transformation:
   *
   *	L = 2^( (Le+.5)/256 - 64 )		# real from 15-bit
   *
   *	Le = floor( 256*(log2(L) + 64) )	# 15-bit from real
   *
   * The actual conversion to world luminance units in candelas per sq. meter
   * requires an additional multiplier, which is stored in the TIFFTAG_STONITS.
   * This value is usually set such that a reasonable exposure comes from
   * clamping decoded luminances above 1 to 1 in the displayed image.
   *
   * The 16-bit values for u and v may be converted to real values by dividing
   * each by 32768.  (This allows for negative values, which aren't useful as
   * far as we know, but are left in case of future improvements in human
   * color vision.)
   *
   * Conversion from (u,v), which is actually the CIE (u',v') system for
   * you color scientists, is accomplished by the following transformation:
   *
   *	u = 4*x / (-2*x + 12*y + 3)
   *	v = 9*y / (-2*x + 12*y + 3)
   *
   *	x = 9*u / (6*u - 16*v + 12)
   *	y = 4*v / (6*u - 16*v + 12)
   *
   * This process is greatly simplified by passing 32-bit IEEE floats
   * for each of three CIE XYZ coordinates.  The codec then takes care
   * of conversion to and from LogLuv, though the application is still
   * responsible for interpreting the TIFFTAG_STONITS calibration factor.
   *
   * By definition, a CIE XYZ vector of [1 1 1] corresponds to a neutral white
   * point of (x,y)=(1/3,1/3).  However, most color systems assume some other
   * white point, such as D65, and an absolute color conversion to XYZ then
   * to another color space with a different white point may introduce an
   * unwanted color cast to the image.  It is often desirable, therefore, to
   * perform a white point conversion that maps the input white to [1 1 1]
   * in XYZ, then record the original white point using the TIFFTAG_WHITEPOINT
   * tag value.  A decoder that demands absolute color calibration may use
   * this white point tag to get back the original colors, but usually it
   * will be ignored and the new white point will be used instead that
   * matches the output color space.
   *
   * Pixel information is compressed into one of two basic encodings, depending
   * on the setting of the compression tag, which is one of COMPRESSION_SGILOG
   * or COMPRESSION_SGILOG24.  For COMPRESSION_SGILOG, greyscale data is
   * stored as:
   *
   *	 1       15
   *	|-+---------------|
   *
   * COMPRESSION_SGILOG color data is stored as:
   *
   *	 1       15           8        8
   *	|-+---------------|--------+--------|
   *	 S       Le           ue       ve
   *
   * For the 24-bit COMPRESSION_SGILOG24 color format, the data is stored as:
   *
   *	     10           14
   *	|----------|--------------|
   *	     Le'          Ce
   *
   * There is no sign bit in the 24-bit case, and the (u,v) chromaticity is
   * encoded as an index for optimal color resolution.  The 10 log bits are
   * defined by the following conversions:
   *
   *	L = 2^((Le'+.5)/64 - 12)		# real from 10-bit
   *
   *	Le' = floor( 64*(log2(L) + 12) )	# 10-bit from real
   *
   * The 10 bits of the smaller format may be converted into the 15 bits of
   * the larger format by multiplying by 4 and adding 13314.  Obviously,
   * a smaller range of magnitudes is covered (about 5 orders of magnitude
   * instead of 38), and the lack of a sign bit means that negative luminances
   * are not allowed.  (Well, they aren't allowed in the real world, either,
   * but they are useful for certain types of image processing.)
   *
   * The desired user format is controlled by the setting the internal
   * pseudo tag TIFFTAG_SGILOGDATAFMT to one of:
   *  SGILOGDATAFMT_FLOAT       = IEEE 32-bit float XYZ values
   *  SGILOGDATAFMT_16BIT	      = 16-bit integer encodings of logL, u and v
   * Raw data i/o is also possible using:
   *  SGILOGDATAFMT_RAW         = 32-bit unsigned integer with encoded pixel
   * In addition, the following decoding is provided for ease of display:
   *  SGILOGDATAFMT_8BIT        = 8-bit default RGB gamma-corrected values
   *
   * For grayscale images, we provide the following data formats:
   *  SGILOGDATAFMT_FLOAT       = IEEE 32-bit float Y values
   *  SGILOGDATAFMT_16BIT       = 16-bit integer w/ encoded luminance
   *  SGILOGDATAFMT_8BIT        = 8-bit gray monitor values
   *
   * Note that the COMPRESSION_SGILOG applies a simple run-length encoding
   * scheme by separating the logL, u and v bytes for each row and applying
   * a PackBits type of compression.  Since the 24-bit encoding is not
   * adaptive, the 32-bit color format takes less space in many cases.
   *
   * Further control is provided over the conversion from higher-resolution
   * formats to final encoded values through the pseudo tag
   * TIFFTAG_SGILOGENCODE:
   *  SGILOGENCODE_NODITHER     = do not dither encoded values
   *  SGILOGENCODE_RANDITHER    = apply random dithering during encoding
   *
   * The default value of this tag is SGILOGENCODE_NODITHER for
   * COMPRESSION_SGILOG to maximize run-length encoding and
   * SGILOGENCODE_RANDITHER for COMPRESSION_SGILOG24 to turn
   * quantization errors into noise.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <math.h>
  
  /*
   * State block for each open TIFF
   * file using LogLuv compression/decompression.
   */
  typedef struct logLuvState LogLuvState;
  
  struct logLuvState {
  	int                     user_datafmt;   /* user data format */
  	int                     encode_meth;    /* encoding method */
  	int                     pixel_size;     /* bytes per pixel */
  
  	uint8*                  tbuf;           /* translation buffer */
  	tmsize_t                tbuflen;        /* buffer length */
  	void (*tfunc)(LogLuvState*, uint8*, tmsize_t);
  
  	TIFFVSetMethod          vgetparent;     /* super-class method */
  	TIFFVSetMethod          vsetparent;     /* super-class method */
  };
  
  #define DecoderState(tif)	((LogLuvState*) (tif)->tif_data)
  #define EncoderState(tif)	((LogLuvState*) (tif)->tif_data)
  
  #define SGILOGDATAFMT_UNKNOWN -1
  
  #define MINRUN 4 /* minimum run length */
  
  /*
   * Decode a string of 16-bit gray pixels.
   */
  static int
  LogL16Decode(TIFF* tif, uint8* op, tmsize_t occ, uint16 s)
  {
  	static const char module[] = "LogL16Decode";
  	LogLuvState* sp = DecoderState(tif);
  	int shft;
  	tmsize_t i;
  	tmsize_t npixels;
  	unsigned char* bp;
  	int16* tp;
  	int16 b;
  	tmsize_t cc;
  	int rc;
  
  	assert(s == 0);
  	assert(sp != NULL);
  
  	npixels = occ / sp->pixel_size;
  
  	if (sp->user_datafmt == SGILOGDATAFMT_16BIT)
  		tp = (int16*) op;
  	else {
  		if(sp->tbuflen < npixels) {
              TIFFErrorExt(tif->tif_clientdata, module,
                      "Translation buffer too short");
              return (0);
          }
  		tp = (int16*) sp->tbuf;
  	}
  	_TIFFmemset((void*) tp, 0, npixels*sizeof (tp[0]));
  
  	bp = (unsigned char*) tif->tif_rawcp;
  	cc = tif->tif_rawcc;
  	/* get each byte string */
  	for (shft = 2*8; (shft -= 8) >= 0; ) {
  		for (i = 0; i < npixels && cc > 0; ) {
  			if (*bp >= 128) {		/* run */
                  if ( cc < 2 )
                      break;
  				rc = *bp++ + (2-128);
  				b = (int16)(*bp++ << shft);
  				cc -= 2;
  				while (rc-- && i < npixels)
  					tp[i++] |= b;
  			} else {			/* non-run */
  				rc = *bp++;		/* nul is noop */
  				while (--cc && rc-- && i < npixels)
  					tp[i++] |= (int16)*bp++ << shft;
  			}
          }
  		if (i != npixels) {
  #if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
  			TIFFErrorExt(tif->tif_clientdata, module,
  			    "Not enough data at row %lu (short %I64d pixels)",
  				     (unsigned long) tif->tif_row,
  				     (unsigned __int64) (npixels - i));
  #else
  			TIFFErrorExt(tif->tif_clientdata, module,
  			    "Not enough data at row %lu (short %llu pixels)",
  				     (unsigned long) tif->tif_row,
  				     (unsigned long long) (npixels - i));
  #endif
  			tif->tif_rawcp = (uint8*) bp;
  			tif->tif_rawcc = cc;
  			return (0);
  		}
  	}
  	(*sp->tfunc)(sp, op, npixels);
  	tif->tif_rawcp = (uint8*) bp;
  	tif->tif_rawcc = cc;
  	return (1);
  }
  
  /*
   * Decode a string of 24-bit pixels.
   */
  static int
  LogLuvDecode24(TIFF* tif, uint8* op, tmsize_t occ, uint16 s)
  {
  	static const char module[] = "LogLuvDecode24";
  	LogLuvState* sp = DecoderState(tif);
  	tmsize_t cc;
  	tmsize_t i;
  	tmsize_t npixels;
  	unsigned char* bp;
  	uint32* tp;
  
  	assert(s == 0);
  	assert(sp != NULL);
  
  	npixels = occ / sp->pixel_size;
  
  	if (sp->user_datafmt == SGILOGDATAFMT_RAW)
  		tp = (uint32 *)op;
  	else {
  		if(sp->tbuflen < npixels) {
              TIFFErrorExt(tif->tif_clientdata, module,
                      "Translation buffer too short");
              return (0);
          }
  		tp = (uint32 *) sp->tbuf;
  	}
  	/* copy to array of uint32 */
  	bp = (unsigned char*) tif->tif_rawcp;
  	cc = tif->tif_rawcc;
  	for (i = 0; i < npixels && cc >= 3; i++) {
  		tp[i] = bp[0] << 16 | bp[1] << 8 | bp[2];
  		bp += 3;
  		cc -= 3;
  	}
  	tif->tif_rawcp = (uint8*) bp;
  	tif->tif_rawcc = cc;
  	if (i != npixels) {
  #if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
  		TIFFErrorExt(tif->tif_clientdata, module,
  			"Not enough data at row %lu (short %I64d pixels)",
  			     (unsigned long) tif->tif_row,
  			     (unsigned __int64) (npixels - i));
  #else
  		TIFFErrorExt(tif->tif_clientdata, module,
  			"Not enough data at row %lu (short %llu pixels)",
  			     (unsigned long) tif->tif_row,
  			     (unsigned long long) (npixels - i));
  #endif
  		return (0);
  	}
  	(*sp->tfunc)(sp, op, npixels);
  	return (1);
  }
  
  /*
   * Decode a string of 32-bit pixels.
   */
  static int
  LogLuvDecode32(TIFF* tif, uint8* op, tmsize_t occ, uint16 s)
  {
  	static const char module[] = "LogLuvDecode32";
  	LogLuvState* sp;
  	int shft;
  	tmsize_t i;
  	tmsize_t npixels;
  	unsigned char* bp;
  	uint32* tp;
  	uint32 b;
  	tmsize_t cc;
  	int rc;
  
  	assert(s == 0);
  	sp = DecoderState(tif);
  	assert(sp != NULL);
  
  	npixels = occ / sp->pixel_size;
  
  	if (sp->user_datafmt == SGILOGDATAFMT_RAW)
  		tp = (uint32*) op;
  	else {
  		if(sp->tbuflen < npixels) {
              TIFFErrorExt(tif->tif_clientdata, module,
                      "Translation buffer too short");
              return (0);
          }
  		tp = (uint32*) sp->tbuf;
  	}
  	_TIFFmemset((void*) tp, 0, npixels*sizeof (tp[0]));
  
  	bp = (unsigned char*) tif->tif_rawcp;
  	cc = tif->tif_rawcc;
  	/* get each byte string */
  	for (shft = 4*8; (shft -= 8) >= 0; ) {
  		for (i = 0; i < npixels && cc > 0; ) {
  			if (*bp >= 128) {		/* run */
                  if ( cc < 2 )
                      break;
  				rc = *bp++ + (2-128);
  				b = (uint32)*bp++ << shft;
  				cc -= 2;
  				while (rc-- && i < npixels)
  					tp[i++] |= b;
  			} else {			/* non-run */
  				rc = *bp++;		/* nul is noop */
  				while (--cc && rc-- && i < npixels)
  					tp[i++] |= (uint32)*bp++ << shft;
  			}
          }
  		if (i != npixels) {
  #if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
  			TIFFErrorExt(tif->tif_clientdata, module,
  			"Not enough data at row %lu (short %I64d pixels)",
  				     (unsigned long) tif->tif_row,
  				     (unsigned __int64) (npixels - i));
  #else
  			TIFFErrorExt(tif->tif_clientdata, module,
  			"Not enough data at row %lu (short %llu pixels)",
  				     (unsigned long) tif->tif_row,
  				     (unsigned long long) (npixels - i));
  #endif
  			tif->tif_rawcp = (uint8*) bp;
  			tif->tif_rawcc = cc;
  			return (0);
  		}
  	}
  	(*sp->tfunc)(sp, op, npixels);
  	tif->tif_rawcp = (uint8*) bp;
  	tif->tif_rawcc = cc;
  	return (1);
  }
  
  /*
   * Decode a strip of pixels.  We break it into rows to
   * maintain synchrony with the encode algorithm, which
   * is row by row.
   */
  static int
  LogLuvDecodeStrip(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
  {
  	tmsize_t rowlen = TIFFScanlineSize(tif);
  
  	assert(cc%rowlen == 0);
  	while (cc && (*tif->tif_decoderow)(tif, bp, rowlen, s))
  		bp += rowlen, cc -= rowlen;
  	return (cc == 0);
  }
  
  /*
   * Decode a tile of pixels.  We break it into rows to
   * maintain synchrony with the encode algorithm, which
   * is row by row.
   */
  static int
  LogLuvDecodeTile(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
  {
  	tmsize_t rowlen = TIFFTileRowSize(tif);
  
  	assert(cc%rowlen == 0);
  	while (cc && (*tif->tif_decoderow)(tif, bp, rowlen, s))
  		bp += rowlen, cc -= rowlen;
  	return (cc == 0);
  }
  
  /*
   * Encode a row of 16-bit pixels.
   */
  static int
  LogL16Encode(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
  {
      static const char module [] = "LogL16Encode";
  	LogLuvState* sp = EncoderState(tif);
  	int shft;
  	tmsize_t i;
  	tmsize_t j;
  	tmsize_t npixels;
  	uint8* op;
  	int16* tp;
  	int16 b;
  	tmsize_t occ;
  	int rc=0, mask;
  	tmsize_t beg;
  
  	assert(s == 0);
  	assert(sp != NULL);
  	npixels = cc / sp->pixel_size;
  
  	if (sp->user_datafmt == SGILOGDATAFMT_16BIT)
  		tp = (int16*) bp;
  	else {
  		tp = (int16*) sp->tbuf;
  		if(sp->tbuflen < npixels) {
              TIFFErrorExt(tif->tif_clientdata, module,
                      "Translation buffer too short");
              return (0);
          }
  		(*sp->tfunc)(sp, bp, npixels);
  	}
  	/* compress each byte string */
  	op = tif->tif_rawcp;
  	occ = tif->tif_rawdatasize - tif->tif_rawcc;
  	for (shft = 2*8; (shft -= 8) >= 0; )
  		for (i = 0; i < npixels; i += rc) {
  			if (occ < 4) {
  				tif->tif_rawcp = op;
  				tif->tif_rawcc = tif->tif_rawdatasize - occ;
  				if (!TIFFFlushData1(tif))
  					return (-1);
  				op = tif->tif_rawcp;
  				occ = tif->tif_rawdatasize - tif->tif_rawcc;
  			}
  			mask = 0xff << shft;		/* find next run */
  			for (beg = i; beg < npixels; beg += rc) {
  				b = (int16) (tp[beg] & mask);
  				rc = 1;
  				while (rc < 127+2 && beg+rc < npixels &&
  				    (tp[beg+rc] & mask) == b)
  					rc++;
  				if (rc >= MINRUN)
  					break;		/* long enough */
  			}
  			if (beg-i > 1 && beg-i < MINRUN) {
  				b = (int16) (tp[i] & mask);/*check short run */
  				j = i+1;
  				while ((tp[j++] & mask) == b)
  					if (j == beg) {
  						*op++ = (uint8)(128-2+j-i);
  						*op++ = (uint8)(b >> shft);
  						occ -= 2;
  						i = beg;
  						break;
  					}
  			}
  			while (i < beg) {		/* write out non-run */
  				if ((j = beg-i) > 127) j = 127;
  				if (occ < j+3) {
  					tif->tif_rawcp = op;
  					tif->tif_rawcc = tif->tif_rawdatasize - occ;
  					if (!TIFFFlushData1(tif))
  						return (-1);
  					op = tif->tif_rawcp;
  					occ = tif->tif_rawdatasize - tif->tif_rawcc;
  				}
  				*op++ = (uint8) j; occ--;
  				while (j--) {
  					*op++ = (uint8) (tp[i++] >> shft & 0xff);
  					occ--;
  				}
  			}
  			if (rc >= MINRUN) {		/* write out run */
  				*op++ = (uint8) (128-2+rc);
  				*op++ = (uint8) (tp[beg] >> shft & 0xff);
  				occ -= 2;
  			} else
  				rc = 0;
  		}
  	tif->tif_rawcp = op;
  	tif->tif_rawcc = tif->tif_rawdatasize - occ;
  
  	return (1);
  }
  
  /*
   * Encode a row of 24-bit pixels.
   */
  static int
  LogLuvEncode24(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
  {
      static const char module [] = "LogLuvEncode24";
  	LogLuvState* sp = EncoderState(tif);
  	tmsize_t i;
  	tmsize_t npixels;
  	tmsize_t occ;
  	uint8* op;
  	uint32* tp;
  
  	assert(s == 0);
  	assert(sp != NULL);
  	npixels = cc / sp->pixel_size;
  
  	if (sp->user_datafmt == SGILOGDATAFMT_RAW)
  		tp = (uint32*) bp;
  	else {
  		tp = (uint32*) sp->tbuf;
  		if(sp->tbuflen < npixels) {
              TIFFErrorExt(tif->tif_clientdata, module,
                      "Translation buffer too short");
              return (0);
          }
  		(*sp->tfunc)(sp, bp, npixels);
  	}
  	/* write out encoded pixels */
  	op = tif->tif_rawcp;
  	occ = tif->tif_rawdatasize - tif->tif_rawcc;
  	for (i = npixels; i--; ) {
  		if (occ < 3) {
  			tif->tif_rawcp = op;
  			tif->tif_rawcc = tif->tif_rawdatasize - occ;
  			if (!TIFFFlushData1(tif))
  				return (-1);
  			op = tif->tif_rawcp;
  			occ = tif->tif_rawdatasize - tif->tif_rawcc;
  		}
  		*op++ = (uint8)(*tp >> 16);
  		*op++ = (uint8)(*tp >> 8 & 0xff);
  		*op++ = (uint8)(*tp++ & 0xff);
  		occ -= 3;
  	}
  	tif->tif_rawcp = op;
  	tif->tif_rawcc = tif->tif_rawdatasize - occ;
  
  	return (1);
  }
  
  /*
   * Encode a row of 32-bit pixels.
   */
  static int
  LogLuvEncode32(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
  {
      static const char module [] = "LogLuvEncode32";
  	LogLuvState* sp = EncoderState(tif);
  	int shft;
  	tmsize_t i;
  	tmsize_t j;
  	tmsize_t npixels;
  	uint8* op;
  	uint32* tp;
  	uint32 b;
  	tmsize_t occ;
  	int rc=0, mask;
  	tmsize_t beg;
  
  	assert(s == 0);
  	assert(sp != NULL);
  
  	npixels = cc / sp->pixel_size;
  
  	if (sp->user_datafmt == SGILOGDATAFMT_RAW)
  		tp = (uint32*) bp;
  	else {
  		tp = (uint32*) sp->tbuf;
  		if(sp->tbuflen < npixels) {
              TIFFErrorExt(tif->tif_clientdata, module,
                      "Translation buffer too short");
              return (0);
          }
  		(*sp->tfunc)(sp, bp, npixels);
  	}
  	/* compress each byte string */
  	op = tif->tif_rawcp;
  	occ = tif->tif_rawdatasize - tif->tif_rawcc;
  	for (shft = 4*8; (shft -= 8) >= 0; )
  		for (i = 0; i < npixels; i += rc) {
  			if (occ < 4) {
  				tif->tif_rawcp = op;
  				tif->tif_rawcc = tif->tif_rawdatasize - occ;
  				if (!TIFFFlushData1(tif))
  					return (-1);
  				op = tif->tif_rawcp;
  				occ = tif->tif_rawdatasize - tif->tif_rawcc;
  			}
  			mask = 0xff << shft;		/* find next run */
  			for (beg = i; beg < npixels; beg += rc) {
  				b = tp[beg] & mask;
  				rc = 1;
  				while (rc < 127+2 && beg+rc < npixels &&
  						(tp[beg+rc] & mask) == b)
  					rc++;
  				if (rc >= MINRUN)
  					break;		/* long enough */
  			}
  			if (beg-i > 1 && beg-i < MINRUN) {
  				b = tp[i] & mask;	/* check short run */
  				j = i+1;
  				while ((tp[j++] & mask) == b)
  					if (j == beg) {
  						*op++ = (uint8)(128-2+j-i);
  						*op++ = (uint8)(b >> shft);
  						occ -= 2;
  						i = beg;
  						break;
  					}
  			}
  			while (i < beg) {		/* write out non-run */
  				if ((j = beg-i) > 127) j = 127;
  				if (occ < j+3) {
  					tif->tif_rawcp = op;
  					tif->tif_rawcc = tif->tif_rawdatasize - occ;
  					if (!TIFFFlushData1(tif))
  						return (-1);
  					op = tif->tif_rawcp;
  					occ = tif->tif_rawdatasize - tif->tif_rawcc;
  				}
  				*op++ = (uint8) j; occ--;
  				while (j--) {
  					*op++ = (uint8)(tp[i++] >> shft & 0xff);
  					occ--;
  				}
  			}
  			if (rc >= MINRUN) {		/* write out run */
  				*op++ = (uint8) (128-2+rc);
  				*op++ = (uint8)(tp[beg] >> shft & 0xff);
  				occ -= 2;
  			} else
  				rc = 0;
  		}
  	tif->tif_rawcp = op;
  	tif->tif_rawcc = tif->tif_rawdatasize - occ;
  
  	return (1);
  }
  
  /*
   * Encode a strip of pixels.  We break it into rows to
   * avoid encoding runs across row boundaries.
   */
  static int
  LogLuvEncodeStrip(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
  {
  	tmsize_t rowlen = TIFFScanlineSize(tif);
  
  	assert(cc%rowlen == 0);
  	while (cc && (*tif->tif_encoderow)(tif, bp, rowlen, s) == 1)
  		bp += rowlen, cc -= rowlen;
  	return (cc == 0);
  }
  
  /*
   * Encode a tile of pixels.  We break it into rows to
   * avoid encoding runs across row boundaries.
   */
  static int
  LogLuvEncodeTile(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
  {
  	tmsize_t rowlen = TIFFTileRowSize(tif);
  
  	assert(cc%rowlen == 0);
  	while (cc && (*tif->tif_encoderow)(tif, bp, rowlen, s) == 1)
  		bp += rowlen, cc -= rowlen;
  	return (cc == 0);
  }
  
  /*
   * Encode/Decode functions for converting to and from user formats.
   */
  
  #include "uvcode.h"
  
  #ifndef UVSCALE
  #define U_NEU		0.210526316
  #define V_NEU		0.473684211
  #define UVSCALE		410.
  #endif
  
  #ifndef	M_LN2
  #define M_LN2		0.69314718055994530942
  #endif
  #ifndef M_PI
  #define M_PI		3.14159265358979323846
  #endif
  #define log2(x)		((1./M_LN2)*log(x))
  #define exp2(x)		exp(M_LN2*(x))
  
  #define itrunc(x,m)	((m)==SGILOGENCODE_NODITHER ? \
  				(int)(x) : \
  				(int)((x) + rand()*(1./RAND_MAX) - .5))
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  double
  LogL16toY(int p16)		/* compute luminance from 16-bit LogL */
  {
  	int	Le = p16 & 0x7fff;
  	double	Y;
  
  	if (!Le)
  		return (0.);
  	Y = exp(M_LN2/256.*(Le+.5) - M_LN2*64.);
  	return (!(p16 & 0x8000) ? Y : -Y);
  }
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  int
  LogL16fromY(double Y, int em)	/* get 16-bit LogL from Y */
  {
  	if (Y >= 1.8371976e19)
  		return (0x7fff);
  	if (Y <= -1.8371976e19)
  		return (0xffff);
  	if (Y > 5.4136769e-20)
  		return itrunc(256.*(log2(Y) + 64.), em);
  	if (Y < -5.4136769e-20)
  		return (~0x7fff | itrunc(256.*(log2(-Y) + 64.), em));
  	return (0);
  }
  
  static void
  L16toY(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	int16* l16 = (int16*) sp->tbuf;
  	float* yp = (float*) op;
  
  	while (n-- > 0)
  		*yp++ = (float)LogL16toY(*l16++);
  }
  
  static void
  L16toGry(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	int16* l16 = (int16*) sp->tbuf;
  	uint8* gp = (uint8*) op;
  
  	while (n-- > 0) {
  		double Y = LogL16toY(*l16++);
  		*gp++ = (uint8) ((Y <= 0.) ? 0 : (Y >= 1.) ? 255 : (int)(256.*sqrt(Y)));
  	}
  }
  
  static void
  L16fromY(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	int16* l16 = (int16*) sp->tbuf;
  	float* yp = (float*) op;
  
  	while (n-- > 0)
  		*l16++ = (int16) (LogL16fromY(*yp++, sp->encode_meth));
  }
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  void
  XYZtoRGB24(float xyz[3], uint8 rgb[3])
  {
  	double	r, g, b;
  					/* assume CCIR-709 primaries */
  	r =  2.690*xyz[0] + -1.276*xyz[1] + -0.414*xyz[2];
  	g = -1.022*xyz[0] +  1.978*xyz[1] +  0.044*xyz[2];
  	b =  0.061*xyz[0] + -0.224*xyz[1] +  1.163*xyz[2];
  					/* assume 2.0 gamma for speed */
  	/* could use integer sqrt approx., but this is probably faster */
  	rgb[0] = (uint8)((r<=0.) ? 0 : (r >= 1.) ? 255 : (int)(256.*sqrt(r)));
  	rgb[1] = (uint8)((g<=0.) ? 0 : (g >= 1.) ? 255 : (int)(256.*sqrt(g)));
  	rgb[2] = (uint8)((b<=0.) ? 0 : (b >= 1.) ? 255 : (int)(256.*sqrt(b)));
  }
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  double
  LogL10toY(int p10)		/* compute luminance from 10-bit LogL */
  {
  	if (p10 == 0)
  		return (0.);
  	return (exp(M_LN2/64.*(p10+.5) - M_LN2*12.));
  }
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  int
  LogL10fromY(double Y, int em)	/* get 10-bit LogL from Y */
  {
  	if (Y >= 15.742)
  		return (0x3ff);
  	else if (Y <= .00024283)
  		return (0);
  	else
  		return itrunc(64.*(log2(Y) + 12.), em);
  }
  
  #define NANGLES		100
  #define uv2ang(u, v)	( (NANGLES*.499999999/M_PI) \
  				* atan2((v)-V_NEU,(u)-U_NEU) + .5*NANGLES )
  
  static int
  oog_encode(double u, double v)		/* encode out-of-gamut chroma */
  {
  	static int	oog_table[NANGLES];
  	static int	initialized = 0;
  	register int	i;
  
  	if (!initialized) {		/* set up perimeter table */
  		double	eps[NANGLES], ua, va, ang, epsa;
  		int	ui, vi, ustep;
  		for (i = NANGLES; i--; )
  			eps[i] = 2.;
  		for (vi = UV_NVS; vi--; ) {
  			va = UV_VSTART + (vi+.5)*UV_SQSIZ;
  			ustep = uv_row[vi].nus-1;
  			if (vi == UV_NVS-1 || vi == 0 || ustep <= 0)
  				ustep = 1;
  			for (ui = uv_row[vi].nus-1; ui >= 0; ui -= ustep) {
  				ua = uv_row[vi].ustart + (ui+.5)*UV_SQSIZ;
  				ang = uv2ang(ua, va);
  				i = (int) ang;
  				epsa = fabs(ang - (i+.5));
  				if (epsa < eps[i]) {
  					oog_table[i] = uv_row[vi].ncum + ui;
  					eps[i] = epsa;
  				}
  			}
  		}
  		for (i = NANGLES; i--; )	/* fill any holes */
  			if (eps[i] > 1.5) {
  				int	i1, i2;
  				for (i1 = 1; i1 < NANGLES/2; i1++)
  					if (eps[(i+i1)%NANGLES] < 1.5)
  						break;
  				for (i2 = 1; i2 < NANGLES/2; i2++)
  					if (eps[(i+NANGLES-i2)%NANGLES] < 1.5)
  						break;
  				if (i1 < i2)
  					oog_table[i] =
  						oog_table[(i+i1)%NANGLES];
  				else
  					oog_table[i] =
  						oog_table[(i+NANGLES-i2)%NANGLES];
  			}
  		initialized = 1;
  	}
  	i = (int) uv2ang(u, v);		/* look up hue angle */
  	return (oog_table[i]);
  }
  
  #undef uv2ang
  #undef NANGLES
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  int
  uv_encode(double u, double v, int em)	/* encode (u',v') coordinates */
  {
  	register int	vi, ui;
  
  	if (v < UV_VSTART)
  		return oog_encode(u, v);
  	vi = itrunc((v - UV_VSTART)*(1./UV_SQSIZ), em);
  	if (vi >= UV_NVS)
  		return oog_encode(u, v);
  	if (u < uv_row[vi].ustart)
  		return oog_encode(u, v);
  	ui = itrunc((u - uv_row[vi].ustart)*(1./UV_SQSIZ), em);
  	if (ui >= uv_row[vi].nus)
  		return oog_encode(u, v);
  
  	return (uv_row[vi].ncum + ui);
  }
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  int
  uv_decode(double *up, double *vp, int c)	/* decode (u',v') index */
  {
  	int	upper, lower;
  	register int	ui, vi;
  
  	if (c < 0 || c >= UV_NDIVS)
  		return (-1);
  	lower = 0;				/* binary search */
  	upper = UV_NVS;
  	while (upper - lower > 1) {
  		vi = (lower + upper) >> 1;
  		ui = c - uv_row[vi].ncum;
  		if (ui > 0)
  			lower = vi;
  		else if (ui < 0)
  			upper = vi;
  		else {
  			lower = vi;
  			break;
  		}
  	}
  	vi = lower;
  	ui = c - uv_row[vi].ncum;
  	*up = uv_row[vi].ustart + (ui+.5)*UV_SQSIZ;
  	*vp = UV_VSTART + (vi+.5)*UV_SQSIZ;
  	return (0);
  }
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  void
  LogLuv24toXYZ(uint32 p, float XYZ[3])
  {
  	int	Ce;
  	double	L, u, v, s, x, y;
  					/* decode luminance */
  	L = LogL10toY(p>>14 & 0x3ff);
  	if (L <= 0.) {
  		XYZ[0] = XYZ[1] = XYZ[2] = 0.;
  		return;
  	}
  					/* decode color */
  	Ce = p & 0x3fff;
  	if (uv_decode(&u, &v, Ce) < 0) {
  		u = U_NEU; v = V_NEU;
  	}
  	s = 1./(6.*u - 16.*v + 12.);
  	x = 9.*u * s;
  	y = 4.*v * s;
  					/* convert to XYZ */
  	XYZ[0] = (float)(x/y * L);
  	XYZ[1] = (float)L;
  	XYZ[2] = (float)((1.-x-y)/y * L);
  }
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  uint32
  LogLuv24fromXYZ(float XYZ[3], int em)
  {
  	int	Le, Ce;
  	double	u, v, s;
  					/* encode luminance */
  	Le = LogL10fromY(XYZ[1], em);
  					/* encode color */
  	s = XYZ[0] + 15.*XYZ[1] + 3.*XYZ[2];
  	if (!Le || s <= 0.) {
  		u = U_NEU;
  		v = V_NEU;
  	} else {
  		u = 4.*XYZ[0] / s;
  		v = 9.*XYZ[1] / s;
  	}
  	Ce = uv_encode(u, v, em);
  	if (Ce < 0)			/* never happens */
  		Ce = uv_encode(U_NEU, V_NEU, SGILOGENCODE_NODITHER);
  					/* combine encodings */
  	return (Le << 14 | Ce);
  }
  
  static void
  Luv24toXYZ(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;  
  	float* xyz = (float*) op;
  
  	while (n-- > 0) {
  		LogLuv24toXYZ(*luv, xyz);
  		xyz += 3;
  		luv++;
  	}
  }
  
  static void
  Luv24toLuv48(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;  
  	int16* luv3 = (int16*) op;
  
  	while (n-- > 0) {
  		double u, v;
  
  		*luv3++ = (int16)((*luv >> 12 & 0xffd) + 13314);
  		if (uv_decode(&u, &v, *luv&0x3fff) < 0) {
  			u = U_NEU;
  			v = V_NEU;
  		}
  		*luv3++ = (int16)(u * (1L<<15));
  		*luv3++ = (int16)(v * (1L<<15));
  		luv++;
  	}
  }
  
  static void
  Luv24toRGB(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;  
  	uint8* rgb = (uint8*) op;
  
  	while (n-- > 0) {
  		float xyz[3];
  
  		LogLuv24toXYZ(*luv++, xyz);
  		XYZtoRGB24(xyz, rgb);
  		rgb += 3;
  	}
  }
  
  static void
  Luv24fromXYZ(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;  
  	float* xyz = (float*) op;
  
  	while (n-- > 0) {
  		*luv++ = LogLuv24fromXYZ(xyz, sp->encode_meth);
  		xyz += 3;
  	}
  }
  
  static void
  Luv24fromLuv48(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;  
  	int16* luv3 = (int16*) op;
  
  	while (n-- > 0) {
  		int Le, Ce;
  
  		if (luv3[0] <= 0)
  			Le = 0;
  		else if (luv3[0] >= (1<<12)+3314)
  			Le = (1<<10) - 1;
  		else if (sp->encode_meth == SGILOGENCODE_NODITHER)
  			Le = (luv3[0]-3314) >> 2;
  		else
  			Le = itrunc(.25*(luv3[0]-3314.), sp->encode_meth);
  
  		Ce = uv_encode((luv3[1]+.5)/(1<<15), (luv3[2]+.5)/(1<<15),
  					sp->encode_meth);
  		if (Ce < 0)	/* never happens */
  			Ce = uv_encode(U_NEU, V_NEU, SGILOGENCODE_NODITHER);
  		*luv++ = (uint32)Le << 14 | Ce;
  		luv3 += 3;
  	}
  }
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  void
  LogLuv32toXYZ(uint32 p, float XYZ[3])
  {
  	double	L, u, v, s, x, y;
  					/* decode luminance */
  	L = LogL16toY((int)p >> 16);
  	if (L <= 0.) {
  		XYZ[0] = XYZ[1] = XYZ[2] = 0.;
  		return;
  	}
  					/* decode color */
  	u = 1./UVSCALE * ((p>>8 & 0xff) + .5);
  	v = 1./UVSCALE * ((p & 0xff) + .5);
  	s = 1./(6.*u - 16.*v + 12.);
  	x = 9.*u * s;
  	y = 4.*v * s;
  					/* convert to XYZ */
  	XYZ[0] = (float)(x/y * L);
  	XYZ[1] = (float)L;
  	XYZ[2] = (float)((1.-x-y)/y * L);
  }
  
  #if !LOGLUV_PUBLIC
  static
  #endif
  uint32
  LogLuv32fromXYZ(float XYZ[3], int em)
  {
  	unsigned int	Le, ue, ve;
  	double	u, v, s;
  					/* encode luminance */
  	Le = (unsigned int)LogL16fromY(XYZ[1], em);
  					/* encode color */
  	s = XYZ[0] + 15.*XYZ[1] + 3.*XYZ[2];
  	if (!Le || s <= 0.) {
  		u = U_NEU;
  		v = V_NEU;
  	} else {
  		u = 4.*XYZ[0] / s;
  		v = 9.*XYZ[1] / s;
  	}
  	if (u <= 0.) ue = 0;
  	else ue = itrunc(UVSCALE*u, em);
  	if (ue > 255) ue = 255;
  	if (v <= 0.) ve = 0;
  	else ve = itrunc(UVSCALE*v, em);
  	if (ve > 255) ve = 255;
  					/* combine encodings */
  	return (Le << 16 | ue << 8 | ve);
  }
  
  static void
  Luv32toXYZ(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;  
  	float* xyz = (float*) op;
  
  	while (n-- > 0) {
  		LogLuv32toXYZ(*luv++, xyz);
  		xyz += 3;
  	}
  }
  
  static void
  Luv32toLuv48(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;  
  	int16* luv3 = (int16*) op;
  
  	while (n-- > 0) {
  		double u, v;
  
  		*luv3++ = (int16)(*luv >> 16);
  		u = 1./UVSCALE * ((*luv>>8 & 0xff) + .5);
  		v = 1./UVSCALE * ((*luv & 0xff) + .5);
  		*luv3++ = (int16)(u * (1L<<15));
  		*luv3++ = (int16)(v * (1L<<15));
  		luv++;
  	}
  }
  
  static void
  Luv32toRGB(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;  
  	uint8* rgb = (uint8*) op;
  
  	while (n-- > 0) {
  		float xyz[3];
  
  		LogLuv32toXYZ(*luv++, xyz);
  		XYZtoRGB24(xyz, rgb);
  		rgb += 3;
  	}
  }
  
  static void
  Luv32fromXYZ(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;  
  	float* xyz = (float*) op;
  
  	while (n-- > 0) {
  		*luv++ = LogLuv32fromXYZ(xyz, sp->encode_meth);
  		xyz += 3;
  	}
  }
  
  static void
  Luv32fromLuv48(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	uint32* luv = (uint32*) sp->tbuf;
  	int16* luv3 = (int16*) op;
  
  	if (sp->encode_meth == SGILOGENCODE_NODITHER) {
  		while (n-- > 0) {
  			*luv++ = (uint32)luv3[0] << 16 |
  				(luv3[1]*(uint32)(UVSCALE+.5) >> 7 & 0xff00) |
  				(luv3[2]*(uint32)(UVSCALE+.5) >> 15 & 0xff);
  			luv3 += 3;
  		}
  		return;
  	}
  	while (n-- > 0) {
  		*luv++ = (uint32)luv3[0] << 16 |
  	(itrunc(luv3[1]*(UVSCALE/(1<<15)), sp->encode_meth) << 8 & 0xff00) |
  		(itrunc(luv3[2]*(UVSCALE/(1<<15)), sp->encode_meth) & 0xff);
  		luv3 += 3;
  	}
  }
  
  static void
  _logLuvNop(LogLuvState* sp, uint8* op, tmsize_t n)
  {
  	(void) sp; (void) op; (void) n;
  }
  
  static int
  LogL16GuessDataFmt(TIFFDirectory *td)
  {
  #define	PACK(s,b,f)	(((b)<<6)|((s)<<3)|(f))
  	switch (PACK(td->td_samplesperpixel, td->td_bitspersample, td->td_sampleformat)) {
  	case PACK(1, 32, SAMPLEFORMAT_IEEEFP):
  		return (SGILOGDATAFMT_FLOAT);
  	case PACK(1, 16, SAMPLEFORMAT_VOID):
  	case PACK(1, 16, SAMPLEFORMAT_INT):
  	case PACK(1, 16, SAMPLEFORMAT_UINT):
  		return (SGILOGDATAFMT_16BIT);
  	case PACK(1,  8, SAMPLEFORMAT_VOID):
  	case PACK(1,  8, SAMPLEFORMAT_UINT):
  		return (SGILOGDATAFMT_8BIT);
  	}
  #undef PACK
  	return (SGILOGDATAFMT_UNKNOWN);
  }
  
  static tmsize_t
  multiply_ms(tmsize_t m1, tmsize_t m2)
  {
          return _TIFFMultiplySSize(NULL, m1, m2, NULL);
  }
  
  static int
  LogL16InitState(TIFF* tif)
  {
  	static const char module[] = "LogL16InitState";
  	TIFFDirectory *td = &tif->tif_dir;
  	LogLuvState* sp = DecoderState(tif);
  
  	assert(sp != NULL);
  	assert(td->td_photometric == PHOTOMETRIC_LOGL);
  
  	/* for some reason, we can't do this in TIFFInitLogL16 */
  	if (sp->user_datafmt == SGILOGDATAFMT_UNKNOWN)
  		sp->user_datafmt = LogL16GuessDataFmt(td);
  	switch (sp->user_datafmt) {
  	case SGILOGDATAFMT_FLOAT:
  		sp->pixel_size = sizeof (float);
  		break;
  	case SGILOGDATAFMT_16BIT:
  		sp->pixel_size = sizeof (int16);
  		break;
  	case SGILOGDATAFMT_8BIT:
  		sp->pixel_size = sizeof (uint8);
  		break;
  	default:
  		TIFFErrorExt(tif->tif_clientdata, module,
  		    "No support for converting user data format to LogL");
  		return (0);
  	}
          if( isTiled(tif) )
              sp->tbuflen = multiply_ms(td->td_tilewidth, td->td_tilelength);
          else
              sp->tbuflen = multiply_ms(td->td_imagewidth, td->td_rowsperstrip);
  	if (multiply_ms(sp->tbuflen, sizeof (int16)) == 0 ||
  	    (sp->tbuf = (uint8*) _TIFFmalloc(sp->tbuflen * sizeof (int16))) == NULL) {
  		TIFFErrorExt(tif->tif_clientdata, module, "No space for SGILog translation buffer");
  		return (0);
  	}
  	return (1);
  }
  
  static int
  LogLuvGuessDataFmt(TIFFDirectory *td)
  {
  	int guess;
  
  	/*
  	 * If the user didn't tell us their datafmt,
  	 * take our best guess from the bitspersample.
  	 */
  #define	PACK(a,b)	(((a)<<3)|(b))
  	switch (PACK(td->td_bitspersample, td->td_sampleformat)) {
  	case PACK(32, SAMPLEFORMAT_IEEEFP):
  		guess = SGILOGDATAFMT_FLOAT;
  		break;
  	case PACK(32, SAMPLEFORMAT_VOID):
  	case PACK(32, SAMPLEFORMAT_UINT):
  	case PACK(32, SAMPLEFORMAT_INT):
  		guess = SGILOGDATAFMT_RAW;
  		break;
  	case PACK(16, SAMPLEFORMAT_VOID):
  	case PACK(16, SAMPLEFORMAT_INT):
  	case PACK(16, SAMPLEFORMAT_UINT):
  		guess = SGILOGDATAFMT_16BIT;
  		break;
  	case PACK( 8, SAMPLEFORMAT_VOID):
  	case PACK( 8, SAMPLEFORMAT_UINT):
  		guess = SGILOGDATAFMT_8BIT;
  		break;
  	default:
  		guess = SGILOGDATAFMT_UNKNOWN;
  		break;
  #undef PACK
  	}
  	/*
  	 * Double-check samples per pixel.
  	 */
  	switch (td->td_samplesperpixel) {
  	case 1:
  		if (guess != SGILOGDATAFMT_RAW)
  			guess = SGILOGDATAFMT_UNKNOWN;
  		break;
  	case 3:
  		if (guess == SGILOGDATAFMT_RAW)
  			guess = SGILOGDATAFMT_UNKNOWN;
  		break;
  	default:
  		guess = SGILOGDATAFMT_UNKNOWN;
  		break;
  	}
  	return (guess);
  }
  
  static int
  LogLuvInitState(TIFF* tif)
  {
  	static const char module[] = "LogLuvInitState";
  	TIFFDirectory* td = &tif->tif_dir;
  	LogLuvState* sp = DecoderState(tif);
  
  	assert(sp != NULL);
  	assert(td->td_photometric == PHOTOMETRIC_LOGLUV);
  
  	/* for some reason, we can't do this in TIFFInitLogLuv */
  	if (td->td_planarconfig != PLANARCONFIG_CONTIG) {
  		TIFFErrorExt(tif->tif_clientdata, module,
  		    "SGILog compression cannot handle non-contiguous data");
  		return (0);
  	}
  	if (sp->user_datafmt == SGILOGDATAFMT_UNKNOWN)
  		sp->user_datafmt = LogLuvGuessDataFmt(td);
  	switch (sp->user_datafmt) {
  	case SGILOGDATAFMT_FLOAT:
  		sp->pixel_size = 3*sizeof (float);
  		break;
  	case SGILOGDATAFMT_16BIT:
  		sp->pixel_size = 3*sizeof (int16);
  		break;
  	case SGILOGDATAFMT_RAW:
  		sp->pixel_size = sizeof (uint32);
  		break;
  	case SGILOGDATAFMT_8BIT:
  		sp->pixel_size = 3*sizeof (uint8);
  		break;
  	default:
  		TIFFErrorExt(tif->tif_clientdata, module,
  		    "No support for converting user data format to LogLuv");
  		return (0);
  	}
          if( isTiled(tif) )
              sp->tbuflen = multiply_ms(td->td_tilewidth, td->td_tilelength);
          else
              sp->tbuflen = multiply_ms(td->td_imagewidth, td->td_rowsperstrip);
  	if (multiply_ms(sp->tbuflen, sizeof (uint32)) == 0 ||
  	    (sp->tbuf = (uint8*) _TIFFmalloc(sp->tbuflen * sizeof (uint32))) == NULL) {
  		TIFFErrorExt(tif->tif_clientdata, module, "No space for SGILog translation buffer");
  		return (0);
  	}
  	return (1);
  }
  
  static int
  LogLuvFixupTags(TIFF* tif)
  {
  	(void) tif;
  	return (1);
  }
  
  static int
  LogLuvSetupDecode(TIFF* tif)
  {
  	static const char module[] = "LogLuvSetupDecode";
  	LogLuvState* sp = DecoderState(tif);
  	TIFFDirectory* td = &tif->tif_dir;
  
  	tif->tif_postdecode = _TIFFNoPostDecode;
  	switch (td->td_photometric) {
  	case PHOTOMETRIC_LOGLUV:
  		if (!LogLuvInitState(tif))
  			break;
  		if (td->td_compression == COMPRESSION_SGILOG24) {
  			tif->tif_decoderow = LogLuvDecode24;
  			switch (sp->user_datafmt) {
  			case SGILOGDATAFMT_FLOAT:
  				sp->tfunc = Luv24toXYZ;  
  				break;
  			case SGILOGDATAFMT_16BIT:
  				sp->tfunc = Luv24toLuv48;  
  				break;
  			case SGILOGDATAFMT_8BIT:
  				sp->tfunc = Luv24toRGB;
  				break;
  			}
  		} else {
  			tif->tif_decoderow = LogLuvDecode32;
  			switch (sp->user_datafmt) {
  			case SGILOGDATAFMT_FLOAT:
  				sp->tfunc = Luv32toXYZ;
  				break;
  			case SGILOGDATAFMT_16BIT:
  				sp->tfunc = Luv32toLuv48;
  				break;
  			case SGILOGDATAFMT_8BIT:
  				sp->tfunc = Luv32toRGB;
  				break;
  			}
  		}
  		return (1);
  	case PHOTOMETRIC_LOGL:
  		if (!LogL16InitState(tif))
  			break;
  		tif->tif_decoderow = LogL16Decode;
  		switch (sp->user_datafmt) {
  		case SGILOGDATAFMT_FLOAT:
  			sp->tfunc = L16toY;
  			break;
  		case SGILOGDATAFMT_8BIT:
  			sp->tfunc = L16toGry;
  			break;
  		}
  		return (1);
  	default:
  		TIFFErrorExt(tif->tif_clientdata, module,
  		    "Inappropriate photometric interpretation %d for SGILog compression; %s",
  		    td->td_photometric, "must be either LogLUV or LogL");
  		break;
  	}
  	return (0);
  }
  
  static int
  LogLuvSetupEncode(TIFF* tif)
  {
  	static const char module[] = "LogLuvSetupEncode";
  	LogLuvState* sp = EncoderState(tif);
  	TIFFDirectory* td = &tif->tif_dir;
  
  	switch (td->td_photometric) {
  	case PHOTOMETRIC_LOGLUV:
  		if (!LogLuvInitState(tif))
  			break;
  		if (td->td_compression == COMPRESSION_SGILOG24) {
  			tif->tif_encoderow = LogLuvEncode24;
  			switch (sp->user_datafmt) {
  			case SGILOGDATAFMT_FLOAT:
  				sp->tfunc = Luv24fromXYZ;
  				break;
  			case SGILOGDATAFMT_16BIT:
  				sp->tfunc = Luv24fromLuv48;  
  				break;
  			case SGILOGDATAFMT_RAW:
  				break;
  			default:
  				goto notsupported;
  			}
  		} else {
  			tif->tif_encoderow = LogLuvEncode32;  
  			switch (sp->user_datafmt) {
  			case SGILOGDATAFMT_FLOAT:
  				sp->tfunc = Luv32fromXYZ;  
  				break;
  			case SGILOGDATAFMT_16BIT:
  				sp->tfunc = Luv32fromLuv48;  
  				break;
  			case SGILOGDATAFMT_RAW:
  				break;
  			default:
  				goto notsupported;
  			}
  		}
  		break;
  	case PHOTOMETRIC_LOGL:
  		if (!LogL16InitState(tif))
  			break;
  		tif->tif_encoderow = LogL16Encode;  
  		switch (sp->user_datafmt) {
  		case SGILOGDATAFMT_FLOAT:
  			sp->tfunc = L16fromY;
  			break;
  		case SGILOGDATAFMT_16BIT:
  			break;
  		default:
  			goto notsupported;
  		}
  		break;
  	default:
  		TIFFErrorExt(tif->tif_clientdata, module,
  		    "Inappropriate photometric interpretation %d for SGILog compression; %s",
  		    td->td_photometric, "must be either LogLUV or LogL");
  		break;
  	}
  	return (1);
  notsupported:
  	TIFFErrorExt(tif->tif_clientdata, module,
  	    "SGILog compression supported only for %s, or raw data",
  	    td->td_photometric == PHOTOMETRIC_LOGL ? "Y, L" : "XYZ, Luv");
  	return (0);
  }
  
  static void
  LogLuvClose(TIFF* tif)
  {
  	TIFFDirectory *td = &tif->tif_dir;
  
  	/*
  	 * For consistency, we always want to write out the same
  	 * bitspersample and sampleformat for our TIFF file,
  	 * regardless of the data format being used by the application.
  	 * Since this routine is called after tags have been set but
  	 * before they have been recorded in the file, we reset them here.
  	 */
  	td->td_samplesperpixel =
  	    (td->td_photometric == PHOTOMETRIC_LOGL) ? 1 : 3;
  	td->td_bitspersample = 16;
  	td->td_sampleformat = SAMPLEFORMAT_INT;
  }
  
  static void
  LogLuvCleanup(TIFF* tif)
  {
  	LogLuvState* sp = (LogLuvState *)tif->tif_data;
  
  	assert(sp != 0);
  
  	tif->tif_tagmethods.vgetfield = sp->vgetparent;
  	tif->tif_tagmethods.vsetfield = sp->vsetparent;
  
  	if (sp->tbuf)
  		_TIFFfree(sp->tbuf);
  	_TIFFfree(sp);
  	tif->tif_data = NULL;
  
  	_TIFFSetDefaultCompressionState(tif);
  }
  
  static int
  LogLuvVSetField(TIFF* tif, uint32 tag, va_list ap)
  {
  	static const char module[] = "LogLuvVSetField";
  	LogLuvState* sp = DecoderState(tif);
  	int bps, fmt;
  
  	switch (tag) {
  	case TIFFTAG_SGILOGDATAFMT:
  		sp->user_datafmt = (int) va_arg(ap, int);
  		/*
  		 * Tweak the TIFF header so that the rest of libtiff knows what
  		 * size of data will be passed between app and library, and
  		 * assume that the app knows what it is doing and is not
  		 * confused by these header manipulations...
  		 */
  		switch (sp->user_datafmt) {
  		case SGILOGDATAFMT_FLOAT:
  			bps = 32, fmt = SAMPLEFORMAT_IEEEFP;
  			break;
  		case SGILOGDATAFMT_16BIT:
  			bps = 16, fmt = SAMPLEFORMAT_INT;
  			break;
  		case SGILOGDATAFMT_RAW:
  			bps = 32, fmt = SAMPLEFORMAT_UINT;
  			TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, 1);
  			break;
  		case SGILOGDATAFMT_8BIT:
  			bps = 8, fmt = SAMPLEFORMAT_UINT;
  			break;
  		default:
  			TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
  			    "Unknown data format %d for LogLuv compression",
  			    sp->user_datafmt);
  			return (0);
  		}
  		TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, bps);
  		TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, fmt);
  		/*
  		 * Must recalculate sizes should bits/sample change.
  		 */
  		tif->tif_tilesize = isTiled(tif) ? TIFFTileSize(tif) : (tmsize_t) -1;
  		tif->tif_scanlinesize = TIFFScanlineSize(tif);
  		return (1);
  	case TIFFTAG_SGILOGENCODE:
  		sp->encode_meth = (int) va_arg(ap, int);
  		if (sp->encode_meth != SGILOGENCODE_NODITHER &&
  		    sp->encode_meth != SGILOGENCODE_RANDITHER) {
  			TIFFErrorExt(tif->tif_clientdata, module,
  			    "Unknown encoding %d for LogLuv compression",
  			    sp->encode_meth);
  			return (0);
  		}
  		return (1);
  	default:
  		return (*sp->vsetparent)(tif, tag, ap);
  	}
  }
  
  static int
  LogLuvVGetField(TIFF* tif, uint32 tag, va_list ap)
  {
  	LogLuvState *sp = (LogLuvState *)tif->tif_data;
  
  	switch (tag) {
  	case TIFFTAG_SGILOGDATAFMT:
  		*va_arg(ap, int*) = sp->user_datafmt;
  		return (1);
  	default:
  		return (*sp->vgetparent)(tif, tag, ap);
  	}
  }
  
  static const TIFFField LogLuvFields[] = {
      { TIFFTAG_SGILOGDATAFMT, 0, 0, TIFF_SHORT, 0, TIFF_SETGET_INT, TIFF_SETGET_UNDEFINED, FIELD_PSEUDO, TRUE, FALSE, "SGILogDataFmt", NULL},
      { TIFFTAG_SGILOGENCODE, 0, 0, TIFF_SHORT, 0, TIFF_SETGET_INT, TIFF_SETGET_UNDEFINED, FIELD_PSEUDO, TRUE, FALSE, "SGILogEncode", NULL}
  };
  
  int
  TIFFInitSGILog(TIFF* tif, int scheme)
  {
  	static const char module[] = "TIFFInitSGILog";
  	LogLuvState* sp;
  
  	assert(scheme == COMPRESSION_SGILOG24 || scheme == COMPRESSION_SGILOG);
  
  	/*
  	 * Merge codec-specific tag information.
  	 */
  	if (!_TIFFMergeFields(tif, LogLuvFields,
  			      TIFFArrayCount(LogLuvFields))) {
  		TIFFErrorExt(tif->tif_clientdata, module,
  		    "Merging SGILog codec-specific tags failed");
  		return 0;
  	}
  
  	/*
  	 * Allocate state block so tag methods have storage to record values.
  	 */
  	tif->tif_data = (uint8*) _TIFFmalloc(sizeof (LogLuvState));
  	if (tif->tif_data == NULL)
  		goto bad;
  	sp = (LogLuvState*) tif->tif_data;
  	_TIFFmemset((void*)sp, 0, sizeof (*sp));
  	sp->user_datafmt = SGILOGDATAFMT_UNKNOWN;
  	sp->encode_meth = (scheme == COMPRESSION_SGILOG24) ?
  	    SGILOGENCODE_RANDITHER : SGILOGENCODE_NODITHER;
  	sp->tfunc = _logLuvNop;
  
  	/*
  	 * Install codec methods.
  	 * NB: tif_decoderow & tif_encoderow are filled
  	 *     in at setup time.
  	 */
  	tif->tif_fixuptags = LogLuvFixupTags;  
  	tif->tif_setupdecode = LogLuvSetupDecode;
  	tif->tif_decodestrip = LogLuvDecodeStrip;
  	tif->tif_decodetile = LogLuvDecodeTile;
  	tif->tif_setupencode = LogLuvSetupEncode;
  	tif->tif_encodestrip = LogLuvEncodeStrip;  
  	tif->tif_encodetile = LogLuvEncodeTile;
  	tif->tif_close = LogLuvClose;
  	tif->tif_cleanup = LogLuvCleanup;
  
  	/*
  	 * Override parent get/set field methods.
  	 */
  	sp->vgetparent = tif->tif_tagmethods.vgetfield;
  	tif->tif_tagmethods.vgetfield = LogLuvVGetField;   /* hook for codec tags */
  	sp->vsetparent = tif->tif_tagmethods.vsetfield;
  	tif->tif_tagmethods.vsetfield = LogLuvVSetField;   /* hook for codec tags */
  
  	return (1);
  bad:
  	TIFFErrorExt(tif->tif_clientdata, module,
  		     "%s: No space for LogLuv state block", tif->tif_name);
  	return (0);
  }
  #endif /* LOGLUV_SUPPORT */
  
  /* vim: set ts=8 sts=8 sw=8 noet: */
  /*
   * Local Variables:
   * mode: c
   * c-basic-offset: 8
   * fill-column: 78
   * End:
   */
  