tif_getimage.c

这是VCF框架的代码

    tsize_t scanline;
    int32 fromskew, toskew;

    buf = (u_char*) _TIFFmalloc(TIFFStripSize(tif));
    if (buf == 0) {
	TIFFError(TIFFFileName(tif), "No space for strip buffer");
	return (0);
    }
    y = setorientation(img, h);
    orientation = img->orientation;
    toskew = -(int32) (orientation == ORIENTATION_TOPLEFT ? w+w : w-w);
    TIFFGetFieldDefaulted(tif, TIFFTAG_ROWSPERSTRIP, &rowsperstrip);
    scanline = TIFFScanlineSize(tif);
    fromskew = (w < imagewidth ? imagewidth - w : 0);
    for (row = 0; row < h; row += rowsperstrip) {
	nrow = (row + rowsperstrip > h ? h - row : rowsperstrip);
	if (TIFFReadEncodedStrip(tif,
                                 TIFFComputeStrip(tif,row+img->row_offset, 0),
                                 buf, nrow*scanline) < 0
            && img->stoponerr)
		break;
	(*put)(img, raster+y*w, 0, y, w, nrow, fromskew, toskew, buf);
	y += (orientation == ORIENTATION_TOPLEFT ?
	    -(int32) nrow : (int32) nrow);
    }
    _TIFFfree(buf);
    return (1);
}

/*
 * Get a strip-organized image with
 *	 SamplesPerPixel > 1
 *	 PlanarConfiguration separated
 * We assume that all such images are RGB.
 */
static int
gtStripSeparate(TIFFRGBAImage* img, uint32* raster, uint32 w, uint32 h)
{
    TIFF* tif = img->tif;
    tileSeparateRoutine put = img->put.separate;
    uint16 orientation;
    u_char *buf;
    u_char *r, *g, *b, *a;
    uint32 row, y, nrow;
    tsize_t scanline;
    uint32 rowsperstrip, offset_row;
    uint32 imagewidth = img->width;
    tsize_t stripsize;
    int32 fromskew, toskew;
    int alpha = img->alpha;

    stripsize = TIFFStripSize(tif);
    r = buf = (u_char *)_TIFFmalloc(4*stripsize);
    if (buf == 0) {
	TIFFError(TIFFFileName(tif), "No space for tile buffer");
	return (0);
    }
    g = r + stripsize;
    b = g + stripsize;
    a = b + stripsize;
    if (!alpha)
	memset(a, 0xff, stripsize);
    y = setorientation(img, h);
    orientation = img->orientation;
    toskew = -(int32) (orientation == ORIENTATION_TOPLEFT ? w+w : w-w);
    TIFFGetFieldDefaulted(tif, TIFFTAG_ROWSPERSTRIP, &rowsperstrip);
    scanline = TIFFScanlineSize(tif);
    fromskew = (w < imagewidth ? imagewidth - w : 0);
    for (row = 0; row < h; row += rowsperstrip) {
	nrow = (row + rowsperstrip > h ? h - row : rowsperstrip);
        offset_row = row + img->row_offset;
	if (TIFFReadEncodedStrip(tif, TIFFComputeStrip(tif, offset_row, 0),
	    r, nrow*scanline) < 0 && img->stoponerr)
	    break;
	if (TIFFReadEncodedStrip(tif, TIFFComputeStrip(tif, offset_row, 1),
	    g, nrow*scanline) < 0 && img->stoponerr)
	    break;
	if (TIFFReadEncodedStrip(tif, TIFFComputeStrip(tif, offset_row, 2),
	    b, nrow*scanline) < 0 && img->stoponerr)
	    break;
	if (alpha &&
	    (TIFFReadEncodedStrip(tif, TIFFComputeStrip(tif, offset_row, 3),
	    a, nrow*scanline) < 0 && img->stoponerr))
	    break;
	(*put)(img, raster+y*w, 0, y, w, nrow, fromskew, toskew, r, g, b, a);
	y += (orientation == ORIENTATION_TOPLEFT ?
	    -(int32) nrow : (int32) nrow);
    }
    _TIFFfree(buf);
    return (1);
}

/*
 * The following routines move decoded data returned
 * from the TIFF library into rasters filled with packed
 * ABGR pixels (i.e. suitable for passing to lrecwrite.)
 *
 * The routines have been created according to the most
 * important cases and optimized.  pickTileContigCase and
 * pickTileSeparateCase analyze the parameters and select
 * the appropriate "put" routine to use.
 */
#define	REPEAT8(op)	REPEAT4(op); REPEAT4(op)
#define	REPEAT4(op)	REPEAT2(op); REPEAT2(op)
#define	REPEAT2(op)	op; op
#define	CASE8(x,op)			\
    switch (x) {			\
    case 7: op; case 6: op; case 5: op;	\
    case 4: op; case 3: op; case 2: op;	\
    case 1: op;				\
    }
#define	CASE4(x,op)	switch (x) { case 3: op; case 2: op; case 1: op; }
#define	NOP

#define	UNROLL8(w, op1, op2) {		\
    uint32 _x;				\
    for (_x = w; _x >= 8; _x -= 8) {	\
	op1;				\
	REPEAT8(op2);			\
    }					\
    if (_x > 0) {			\
	op1;				\
	CASE8(_x,op2);			\
    }					\
}
#define	UNROLL4(w, op1, op2) {		\
    uint32 _x;				\
    for (_x = w; _x >= 4; _x -= 4) {	\
	op1;				\
	REPEAT4(op2);			\
    }					\
    if (_x > 0) {			\
	op1;				\
	CASE4(_x,op2);			\
    }					\
}
#define	UNROLL2(w, op1, op2) {		\
    uint32 _x;				\
    for (_x = w; _x >= 2; _x -= 2) {	\
	op1;				\
	REPEAT2(op2);			\
    }					\
    if (_x) {				\
	op1;				\
	op2;				\
    }					\
}
    
#define	SKEW(r,g,b,skew)	{ r += skew; g += skew; b += skew; }
#define	SKEW4(r,g,b,a,skew)	{ r += skew; g += skew; b += skew; a+= skew; }

#define A1 ((uint32)(0xffL<<24))
#define	PACK(r,g,b)	\
	((uint32)(r)|((uint32)(g)<<8)|((uint32)(b)<<16)|A1)
#define	PACK4(r,g,b,a)	\
	((uint32)(r)|((uint32)(g)<<8)|((uint32)(b)<<16)|((uint32)(a)<<24))
#define W2B(v) (((v)>>8)&0xff)
#define	PACKW(r,g,b)	\
	((uint32)W2B(r)|((uint32)W2B(g)<<8)|((uint32)W2B(b)<<16)|A1)
#define	PACKW4(r,g,b,a)	\
	((uint32)W2B(r)|((uint32)W2B(g)<<8)|((uint32)W2B(b)<<16)|((uint32)W2B(a)<<24))

#define	DECLAREContigPutFunc(name) \
static void name(\
    TIFFRGBAImage* img, \
    uint32* cp, \
    uint32 x, uint32 y, \
    uint32 w, uint32 h, \
    int32 fromskew, int32 toskew, \
    u_char* pp \
)

/*
 * 8-bit palette => colormap/RGB
 */
DECLAREContigPutFunc(put8bitcmaptile)
{
    uint32** PALmap = img->PALmap;

    (void) x; (void) y;
    while (h-- > 0) {
	UNROLL8(w, NOP, *cp++ = PALmap[*pp++][0]);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 4-bit palette => colormap/RGB
 */
DECLAREContigPutFunc(put4bitcmaptile)
{
    uint32** PALmap = img->PALmap;

    (void) x; (void) y;
    fromskew /= 2;
    while (h-- > 0) {
	uint32* bw;
	UNROLL2(w, bw = PALmap[*pp++], *cp++ = *bw++);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 2-bit palette => colormap/RGB
 */
DECLAREContigPutFunc(put2bitcmaptile)
{
    uint32** PALmap = img->PALmap;

    (void) x; (void) y;
    fromskew /= 4;
    while (h-- > 0) {
	uint32* bw;
	UNROLL4(w, bw = PALmap[*pp++], *cp++ = *bw++);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 1-bit palette => colormap/RGB
 */
DECLAREContigPutFunc(put1bitcmaptile)
{
    uint32** PALmap = img->PALmap;

    (void) x; (void) y;
    fromskew /= 8;
    while (h-- > 0) {
	uint32* bw;
	UNROLL8(w, bw = PALmap[*pp++], *cp++ = *bw++);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 8-bit greyscale => colormap/RGB
 */
DECLAREContigPutFunc(putgreytile)
{
    uint32** BWmap = img->BWmap;

    (void) y;
    while (h-- > 0) {
	for (x = w; x-- > 0;)
	    *cp++ = BWmap[*pp++][0];
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 1-bit bilevel => colormap/RGB
 */
DECLAREContigPutFunc(put1bitbwtile)
{
    uint32** BWmap = img->BWmap;

    (void) x; (void) y;
    fromskew /= 8;
    while (h-- > 0) {
	uint32* bw;
	UNROLL8(w, bw = BWmap[*pp++], *cp++ = *bw++);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 2-bit greyscale => colormap/RGB
 */
DECLAREContigPutFunc(put2bitbwtile)
{
    uint32** BWmap = img->BWmap;

    (void) x; (void) y;
    fromskew /= 4;
    while (h-- > 0) {
	uint32* bw;
	UNROLL4(w, bw = BWmap[*pp++], *cp++ = *bw++);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 4-bit greyscale => colormap/RGB
 */
DECLAREContigPutFunc(put4bitbwtile)
{
    uint32** BWmap = img->BWmap;

    (void) x; (void) y;
    fromskew /= 2;
    while (h-- > 0) {
	uint32* bw;
	UNROLL2(w, bw = BWmap[*pp++], *cp++ = *bw++);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 8-bit packed samples, no Map => RGB
 */
DECLAREContigPutFunc(putRGBcontig8bittile)
{
    int samplesperpixel = img->samplesperpixel;

    (void) x; (void) y;
    fromskew *= samplesperpixel;
    while (h-- > 0) {
	UNROLL8(w, NOP,
	    *cp++ = PACK(pp[0], pp[1], pp[2]);
	    pp += samplesperpixel);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 8-bit packed samples, w/ Map => RGB
 */
DECLAREContigPutFunc(putRGBcontig8bitMaptile)
{
    TIFFRGBValue* Map = img->Map;
    int samplesperpixel = img->samplesperpixel;

    (void) y;
    fromskew *= samplesperpixel;
    while (h-- > 0) {
	for (x = w; x-- > 0;) {
	    *cp++ = PACK(Map[pp[0]], Map[pp[1]], Map[pp[2]]);
	    pp += samplesperpixel;
	}
	pp += fromskew;
	cp += toskew;
    }
}

/*
 * 8-bit packed samples => RGBA w/ associated alpha
 * (known to have Map == NULL)
 */
DECLAREContigPutFunc(putRGBAAcontig8bittile)
{
    int samplesperpixel = img->samplesperpixel;

    (void) x; (void) y;
    fromskew *= samplesperpixel;
    while (h-- > 0) {
	UNROLL8(w, NOP,
	    *cp++ = PACK4(pp[0], pp[1], pp[2], pp[3]);
	    pp += samplesperpixel);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 8-bit packed samples => RGBA w/ unassociated alpha
 * (known to have Map == NULL)
 */
DECLAREContigPutFunc(putRGBUAcontig8bittile)
{
    int samplesperpixel = img->samplesperpixel;

    (void) y;
    fromskew *= samplesperpixel;
    while (h-- > 0) {
	uint32 r, g, b, a;
	for (x = w; x-- > 0;) {
	    a = pp[3];
	    r = (pp[0] * a) / 255;
	    g = (pp[1] * a) / 255;
	    b = (pp[2] * a) / 255;
	    *cp++ = PACK4(r,g,b,a);
	    pp += samplesperpixel;
	}
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 16-bit packed samples => RGB
 */
DECLAREContigPutFunc(putRGBcontig16bittile)
{
    int samplesperpixel = img->samplesperpixel;
    uint16 *wp = (uint16 *)pp;

    (void) y;
    fromskew *= samplesperpixel;
    while (h-- > 0) {
	for (x = w; x-- > 0;) {
	    *cp++ = PACKW(wp[0], wp[1], wp[2]);
	    wp += samplesperpixel;
	}
	cp += toskew;
	wp += fromskew;
    }
}

/*
 * 16-bit packed samples => RGBA w/ associated alpha
 * (known to have Map == NULL)
 */
DECLAREContigPutFunc(putRGBAAcontig16bittile)
{
    int samplesperpixel = img->samplesperpixel;
    uint16 *wp = (uint16 *)pp;

    (void) y;
    fromskew *= samplesperpixel;
    while (h-- > 0) {
	for (x = w; x-- > 0;) {
	    *cp++ = PACKW4(wp[0], wp[1], wp[2], wp[3]);
	    wp += samplesperpixel;
	}
	cp += toskew;
	wp += fromskew;
    }
}

/*
 * 16-bit packed samples => RGBA w/ unassociated alpha
 * (known to have Map == NULL)
 */
DECLAREContigPutFunc(putRGBUAcontig16bittile)
{
    int samplesperpixel = img->samplesperpixel;
    uint16 *wp = (uint16 *)pp;

    (void) y;
    fromskew *= samplesperpixel;
    while (h-- > 0) {
	uint32 r,g,b,a;
	/*
	 * We shift alpha down four bits just in case unsigned
	 * arithmetic doesn't handle the full range.
	 * We still have plenty of accuracy, since the output is 8 bits.
	 * So we have (r * 0xffff) * (a * 0xfff)) = r*a * (0xffff*0xfff)
	 * Since we want r*a * 0xff for eight bit output,
	 * we divide by (0xffff * 0xfff) / 0xff == 0x10eff.
	 */
	for (x = w; x-- > 0;) {
	    a = wp[3] >> 4; 
	    r = (wp[0] * a) / 0x10eff;
	    g = (wp[1] * a) / 0x10eff;
	    b = (wp[2] * a) / 0x10eff;
	    *cp++ = PACK4(r,g,b,a);
	    wp += samplesperpixel;
	}
	cp += toskew;
	wp += fromskew;
    }
}

/*
 * 8-bit packed CMYK samples w/o Map => RGB
 *
 * NB: The conversion of CMYK->RGB is *very* crude.
 */
DECLAREContigPutFunc(putRGBcontig8bitCMYKtile)
{
    int samplesperpixel = img->samplesperpixel;
    uint16 r, g, b, k;

    (void) x; (void) y;
    fromskew *= samplesperpixel;
    while (h-- > 0) {
	UNROLL8(w, NOP,
	    k = 255 - pp[3];
	    r = (k*(255-pp[0]))/255;
	    g = (k*(255-pp[1]))/255;
	    b = (k*(255-pp[2]))/255;
	    *cp++ = PACK(r, g, b);
	    pp += samplesperpixel);
	cp += toskew;
	pp += fromskew;
    }
}

/*
 * 8-bit packed CMYK samples w/Map => RGB
 *
 * NB: The conversion of CMYK->RGB is *very* crude.
 */
DECLAREContigPutFunc(putRGBcontig8bitCMYKMaptile)
{
    int samplesperpixel = img->samplesperpixel;
    TIFFRGBValue* Map = img->Map;
    uint16 r, g, b, k;

    (void) y;
    fromskew *= samplesperpixel;
    while (h-- > 0) {
	for (x = w; x-- > 0;) {
	    k = 255 - pp[3];
	    r = (k*(255-pp[0]))/255;
	    g = (k*(255-pp[1]))/255;
	    b = (k*(255-pp[2]))/255;
	    *cp++ = PACK(Map[r], Map[g], Map[b]);
	    pp += samplesperpixel;
	}
	pp += fromskew;
	cp += toskew;
    }
}

#define	DECLARESepPutFunc(name) \
static void name(\
    TIFFRGBAImage* img,\
    uint32* cp,\
    uint32 x, uint32 y, \
    uint32 w, uint32 h,\
    int32 fromskew, int32 toskew,\
    u_char* r, u_char* g, u_char* b, u_char* a\
)

/*
 * 8-bit unpacked samples => RGB
 */
DECLARESepPutFunc(putRGBseparate8bittile)
{
    (void) img; (void) x; (void) y; (void) a;
    while (h-- > 0) {
	UNROLL8(w, NOP, *cp++ = PACK(*r++, *g++, *b++));
	SKEW(r, g, b, fromskew);
	cp += toskew;
    }
}

/*
 * 8-bit unpacked samples => RGB
 */
DECLARESepPutFunc(putRGBseparate8bitMaptile)
{
    TIFFRGBValue* Map = img->Map;

    (void) y; (void) a;
    while (h-- > 0) {
	for (x = w; x > 0; x--)
	    *cp++ = PACK(Map[*r++], Map[*g++], Map[*b++]);
	SKEW(r, g, b, fromskew);
	cp += toskew;
    }
}

/*
 * 8-bit unpacked samples => RGBA w/ associated alpha
 */
DECLARESepPutFunc(putRGBAAseparate8bittile)
{
    (void) img; (void) x; (void) y;
    while (h-- > 0) {
	UNROLL8(w, NOP, *cp++ = PACK4(*r++, *g++, *b++, *a++));
	SKEW4(r, g, b, a, fromskew);
	cp += toskew;
    }
}

/*
 * 8-bit unpacked samples => RGBA w/ unassociated alpha
 */
DECLARESepPutFunc(putRGBUAseparate8bittile)
{
    (void) img; (void) y;
    while (h-- > 0) {
	uint32 rv, gv, bv, av;