tif_pixarlog.c

一个国人自己实现图像库的程序（有参考价值）

/*
 * Copyright (c) 1996-1997 Sam Leffler
 * Copyright (c) 1996 Pixar
 *
 * 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
 * Pixar, 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 Pixar, 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 PIXAR, 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.
 */

#include "tiffiop.h"
#ifdef PIXARLOG_SUPPORT

/*
 * TIFF Library.
 * PixarLog Compression Support
 *
 * Contributed by Dan McCoy.
 *
 * PixarLog film support uses the TIFF library to store companded
 * 11 bit values into a tiff file, which are compressed using the 
 * zip compressor.  
 *
 * The codec can take as input and produce as output 32-bit IEEE float values 
 * as well as 16-bit or 8-bit unsigned integer values.
 *
 * On writing any of the above are converted into the internal
 * 11-bit log format.   In the case of  8 and 16 bit values, the
 * input is assumed to be unsigned linear color values that represent
 * the range 0-1.  In the case of IEEE values, the 0-1 range is assumed to
 * be the normal linear color range, in addition over 1 values are
 * accepted up to a value of about 25.0 to encode "hot" hightlights and such.
 * The encoding is lossless for 8-bit values, slightly lossy for the
 * other bit depths.  The actual color precision should be better
 * than the human eye can perceive with extra room to allow for
 * error introduced by further image computation.  As with any quantized
 * color format, it is possible to perform image calculations which
 * expose the quantization error. This format should certainly be less 
 * susceptable to such errors than standard 8-bit encodings, but more
 * susceptable than straight 16-bit or 32-bit encodings.
 *
 * On reading the internal format is converted to the desired output format.
 * The program can request which format it desires by setting the internal
 * pseudo tag TIFFTAG_PIXARLOGDATAFMT to one of these possible values:
 *  PIXARLOGDATAFMT_FLOAT     = provide IEEE float values.
 *  PIXARLOGDATAFMT_16BIT     = provide unsigned 16-bit integer values
 *  PIXARLOGDATAFMT_8BIT      = provide unsigned 8-bit integer values
 *
 * alternately PIXARLOGDATAFMT_8BITABGR provides unsigned 8-bit integer
 * values with the difference that if there are exactly three or four channels
 * (rgb or rgba) it swaps the channel order (bgr or abgr).
 *
 * PIXARLOGDATAFMT_11BITLOG provides the internal encoding directly
 * packed in 16-bit values.   However no tools are supplied for interpreting
 * these values.
 *
 * "hot" (over 1.0) areas written in floating point get clamped to
 * 1.0 in the integer data types.
 *
 * When the file is closed after writing, the bit depth and sample format
 * are set always to appear as if 8-bit data has been written into it.
 * That way a naive program unaware of the particulars of the encoding
 * gets the format it is most likely able to handle.
 *
 * The codec does it's own horizontal differencing step on the coded
 * values so the libraries predictor stuff should be turned off.
 * The codec also handle byte swapping the encoded values as necessary
 * since the library does not have the information necessary
 * to know the bit depth of the raw unencoded buffer.
 * 
 */

#include "tif_predict.h"
#include "zlib.h"
#include "zutil.h"

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

/* Tables for converting to/from 11 bit coded values */

#define  TSIZE	 2048		/* decode table size (11-bit tokens) */
#define  TSIZEP1 2049		/* Plus one for slop */
#define  ONE	 1250		/* token value of 1.0 exactly */
#define  RATIO	 1.004		/* nominal ratio for log part */

#define CODE_MASK 0x7ff         /* 11 bits. */

static float  Fltsize;
static float  LogK1, LogK2;

#define REPEAT(n, op)   { int i; i=n; do { i--; op; } while (i>0); }

static void
horizontalAccumulateF(uint16 *wp, int n, int stride, float *op, 
	float *ToLinearF)
{
    register unsigned int  cr, cg, cb, ca, mask;
    register float  t0, t1, t2, t3;

    if (n >= stride) {
	mask = CODE_MASK;
	if (stride == 3) {
	    t0 = ToLinearF[cr = wp[0]];
	    t1 = ToLinearF[cg = wp[1]];
	    t2 = ToLinearF[cb = wp[2]];
	    op[0] = t0;
	    op[1] = t1;
	    op[2] = t2;
	    n -= 3;
	    while (n > 0) {
		wp += 3;
		op += 3;
		n -= 3;
		t0 = ToLinearF[(cr += wp[0]) & mask];
		t1 = ToLinearF[(cg += wp[1]) & mask];
		t2 = ToLinearF[(cb += wp[2]) & mask];
		op[0] = t0;
		op[1] = t1;
		op[2] = t2;
	    }
	} else if (stride == 4) {
	    t0 = ToLinearF[cr = wp[0]];
	    t1 = ToLinearF[cg = wp[1]];
	    t2 = ToLinearF[cb = wp[2]];
	    t3 = ToLinearF[ca = wp[3]];
	    op[0] = t0;
	    op[1] = t1;
	    op[2] = t2;
	    op[3] = t3;
	    n -= 4;
	    while (n > 0) {
		wp += 4;
		op += 4;
		n -= 4;
		t0 = ToLinearF[(cr += wp[0]) & mask];
		t1 = ToLinearF[(cg += wp[1]) & mask];
		t2 = ToLinearF[(cb += wp[2]) & mask];
		t3 = ToLinearF[(ca += wp[3]) & mask];
		op[0] = t0;
		op[1] = t1;
		op[2] = t2;
		op[3] = t3;
	    }
	} else {
	    REPEAT(stride, *op = ToLinearF[*wp&mask]; wp++; op++)
	    n -= stride;
	    while (n > 0) {
		REPEAT(stride,
		    wp[stride] += *wp; *op = ToLinearF[*wp&mask]; wp++; op++)
		n -= stride;
	    }
	}
    }
}

static void
horizontalAccumulate12(uint16 *wp, int n, int stride, int16 *op,
	float *ToLinearF)
{
    register unsigned int  cr, cg, cb, ca, mask;
    register float  t0, t1, t2, t3;

#define SCALE12 2048.0
#define CLAMP12(t) (((t) < 3071) ? (uint16) (t) : 3071)

    if (n >= stride) {
	mask = CODE_MASK;
	if (stride == 3) {
	    t0 = ToLinearF[cr = wp[0]] * SCALE12;
	    t1 = ToLinearF[cg = wp[1]] * SCALE12;
	    t2 = ToLinearF[cb = wp[2]] * SCALE12;
	    op[0] = CLAMP12(t0);
	    op[1] = CLAMP12(t1);
	    op[2] = CLAMP12(t2);
	    n -= 3;
	    while (n > 0) {
		wp += 3;
		op += 3;
		n -= 3;
		t0 = ToLinearF[(cr += wp[0]) & mask] * SCALE12;
		t1 = ToLinearF[(cg += wp[1]) & mask] * SCALE12;
		t2 = ToLinearF[(cb += wp[2]) & mask] * SCALE12;
		op[0] = CLAMP12(t0);
		op[1] = CLAMP12(t1);
		op[2] = CLAMP12(t2);
	    }
	} else if (stride == 4) {
	    t0 = ToLinearF[cr = wp[0]] * SCALE12;
	    t1 = ToLinearF[cg = wp[1]] * SCALE12;
	    t2 = ToLinearF[cb = wp[2]] * SCALE12;
	    t3 = ToLinearF[ca = wp[3]] * SCALE12;
	    op[0] = CLAMP12(t0);
	    op[1] = CLAMP12(t1);
	    op[2] = CLAMP12(t2);
	    op[3] = CLAMP12(t3);
	    n -= 4;
	    while (n > 0) {
		wp += 4;
		op += 4;
		n -= 4;
		t0 = ToLinearF[(cr += wp[0]) & mask] * SCALE12;
		t1 = ToLinearF[(cg += wp[1]) & mask] * SCALE12;
		t2 = ToLinearF[(cb += wp[2]) & mask] * SCALE12;
		t3 = ToLinearF[(ca += wp[3]) & mask] * SCALE12;
		op[0] = CLAMP12(t0);
		op[1] = CLAMP12(t1);
		op[2] = CLAMP12(t2);
		op[3] = CLAMP12(t3);
	    }
	} else {
	    REPEAT(stride, t0 = ToLinearF[*wp&mask] * SCALE12;
                           *op = CLAMP12(t0); wp++; op++)
	    n -= stride;
	    while (n > 0) {
		REPEAT(stride,
		    wp[stride] += *wp; t0 = ToLinearF[wp[stride]&mask]*SCALE12;
		    *op = CLAMP12(t0);  wp++; op++)
		n -= stride;
	    }
	}
    }
}

static void
horizontalAccumulate16(uint16 *wp, int n, int stride, uint16 *op,
	uint16 *ToLinear16)
{
    register unsigned int  cr, cg, cb, ca, mask;

    if (n >= stride) {
	mask = CODE_MASK;
	if (stride == 3) {
	    op[0] = ToLinear16[cr = wp[0]];
	    op[1] = ToLinear16[cg = wp[1]];
	    op[2] = ToLinear16[cb = wp[2]];
	    n -= 3;
	    while (n > 0) {
		wp += 3;
		op += 3;
		n -= 3;
		op[0] = ToLinear16[(cr += wp[0]) & mask];
		op[1] = ToLinear16[(cg += wp[1]) & mask];
		op[2] = ToLinear16[(cb += wp[2]) & mask];
	    }
	} else if (stride == 4) {
	    op[0] = ToLinear16[cr = wp[0]];
	    op[1] = ToLinear16[cg = wp[1]];
	    op[2] = ToLinear16[cb = wp[2]];
	    op[3] = ToLinear16[ca = wp[3]];
	    n -= 4;
	    while (n > 0) {
		wp += 4;
		op += 4;
		n -= 4;
		op[0] = ToLinear16[(cr += wp[0]) & mask];
		op[1] = ToLinear16[(cg += wp[1]) & mask];
		op[2] = ToLinear16[(cb += wp[2]) & mask];
		op[3] = ToLinear16[(ca += wp[3]) & mask];
	    }
	} else {
	    REPEAT(stride, *op = ToLinear16[*wp&mask]; wp++; op++)
	    n -= stride;
	    while (n > 0) {
		REPEAT(stride,
		    wp[stride] += *wp; *op = ToLinear16[*wp&mask]; wp++; op++)
		n -= stride;
	    }
	}
    }
}

/* 
 * Returns the log encoded 11-bit values with the horizontal
 * differencing undone.
 */
static void
horizontalAccumulate11(uint16 *wp, int n, int stride, uint16 *op)
{
    register unsigned int  cr, cg, cb, ca, mask;

    if (n >= stride) {
	mask = CODE_MASK;
	if (stride == 3) {
	    op[0] = cr = wp[0];  op[1] = cg = wp[1];  op[2] = cb = wp[2];
	    n -= 3;
	    while (n > 0) {
		wp += 3;
		op += 3;
		n -= 3;
		op[0] = (cr += wp[0]) & mask;
		op[1] = (cg += wp[1]) & mask;
		op[2] = (cb += wp[2]) & mask;
	    }
	} else if (stride == 4) {
	    op[0] = cr = wp[0];  op[1] = cg = wp[1];
	    op[2] = cb = wp[2];  op[3] = ca = wp[3];
	    n -= 4;
	    while (n > 0) {
		wp += 4;
		op += 4;
		n -= 4;
		op[0] = (cr += wp[0]) & mask;
		op[1] = (cg += wp[1]) & mask;
		op[2] = (cb += wp[2]) & mask;
		op[3] = (ca += wp[3]) & mask;
	    } 
	} else {
	    REPEAT(stride, *op = *wp&mask; wp++; op++)
	    n -= stride;
	    while (n > 0) {
		REPEAT(stride,
		    wp[stride] += *wp; *op = *wp&mask; wp++; op++)
	    	n -= stride;
	    }
	}
    }
}

static void
horizontalAccumulate8(uint16 *wp, int n, int stride, unsigned char *op,
	unsigned char *ToLinear8)
{
    register unsigned int  cr, cg, cb, ca, mask;

    if (n >= stride) {
	mask = CODE_MASK;
	if (stride == 3) {
	    op[0] = ToLinear8[cr = wp[0]];
	    op[1] = ToLinear8[cg = wp[1]];
	    op[2] = ToLinear8[cb = wp[2]];
	    n -= 3;
	    while (n > 0) {
		n -= 3;
		wp += 3;
		op += 3;
		op[0] = ToLinear8[(cr += wp[0]) & mask];
		op[1] = ToLinear8[(cg += wp[1]) & mask];
		op[2] = ToLinear8[(cb += wp[2]) & mask];
	    }
	} else if (stride == 4) {
	    op[0] = ToLinear8[cr = wp[0]];
	    op[1] = ToLinear8[cg = wp[1]];
	    op[2] = ToLinear8[cb = wp[2]];
	    op[3] = ToLinear8[ca = wp[3]];
	    n -= 4;
	    while (n > 0) {
		n -= 4;
		wp += 4;
		op += 4;
		op[0] = ToLinear8[(cr += wp[0]) & mask];
		op[1] = ToLinear8[(cg += wp[1]) & mask];
		op[2] = ToLinear8[(cb += wp[2]) & mask];
		op[3] = ToLinear8[(ca += wp[3]) & mask];
	    }
	} else {
	    REPEAT(stride, *op = ToLinear8[*wp&mask]; wp++; op++)
	    n -= stride;
	    while (n > 0) {
		REPEAT(stride,
		    wp[stride] += *wp; *op = ToLinear8[*wp&mask]; wp++; op++)
		n -= stride;
	    }
	}
    }
}


static void
horizontalAccumulate8abgr(uint16 *wp, int n, int stride, unsigned char *op,
	unsigned char *ToLinear8)
{
    register unsigned int  cr, cg, cb, ca, mask;
    register unsigned char  t0, t1, t2, t3;

    if (n >= stride) {
	mask = CODE_MASK;
	if (stride == 3) {
	    op[0] = 0;
	    t1 = ToLinear8[cb = wp[2]];
	    t2 = ToLinear8[cg = wp[1]];
	    t3 = ToLinear8[cr = wp[0]];
	    op[1] = t1;
	    op[2] = t2;
	    op[3] = t3;
	    n -= 3;
	    while (n > 0) {
		n -= 3;
		wp += 3;
		op += 4;
		op[0] = 0;
		t1 = ToLinear8[(cb += wp[2]) & mask];
		t2 = ToLinear8[(cg += wp[1]) & mask];
		t3 = ToLinear8[(cr += wp[0]) & mask];
		op[1] = t1;
		op[2] = t2;
		op[3] = t3;
	    }
	} else if (stride == 4) {
	    t0 = ToLinear8[ca = wp[3]];
	    t1 = ToLinear8[cb = wp[2]];
	    t2 = ToLinear8[cg = wp[1]];
	    t3 = ToLinear8[cr = wp[0]];
	    op[0] = t0;
	    op[1] = t1;
	    op[2] = t2;
	    op[3] = t3;
	    n -= 4;
	    while (n > 0) {
		n -= 4;
		wp += 4;
		op += 4;
		t0 = ToLinear8[(ca += wp[3]) & mask];
		t1 = ToLinear8[(cb += wp[2]) & mask];
		t2 = ToLinear8[(cg += wp[1]) & mask];
		t3 = ToLinear8[(cr += wp[0]) & mask];
		op[0] = t0;
		op[1] = t1;
		op[2] = t2;
		op[3] = t3;
	    }