--- /dev/null
+/* $Id: tif_strip.c,v 1.1 2005-06-17 13:54:52 vp153 Exp $ */
+
+/*
+ * Copyright (c) 1991-1997 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.
+ *
+ * Strip-organized Image Support Routines.
+ */
+#include "tiffiop.h"
+
+static uint32
+summarize(TIFF* tif, size_t summand1, size_t summand2, const char* where)
+{
+ /*
+ * XXX: We are using casting to uint32 here, bacause sizeof(size_t)
+ * may be larger than sizeof(uint32) on 64-bit architectures.
+ */
+ uint32 bytes = summand1 + summand2;
+
+ if (bytes - summand1 != summand2) {
+ TIFFError(tif->tif_name, "Integer overflow in %s", where);
+ bytes = 0;
+ }
+
+ return (bytes);
+}
+
+static uint32
+multiply(TIFF* tif, size_t nmemb, size_t elem_size, const char* where)
+{
+ uint32 bytes = nmemb * elem_size;
+
+ if (elem_size && bytes / elem_size != nmemb) {
+ TIFFError(tif->tif_name, "Integer overflow in %s", where);
+ bytes = 0;
+ }
+
+ return (bytes);
+}
+
+/*
+ * Compute which strip a (row,sample) value is in.
+ */
+tstrip_t
+TIFFComputeStrip(TIFF* tif, uint32 row, tsample_t sample)
+{
+ TIFFDirectory *td = &tif->tif_dir;
+ tstrip_t strip;
+
+ strip = row / td->td_rowsperstrip;
+ if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {
+ if (sample >= td->td_samplesperpixel) {
+ TIFFError(tif->tif_name,
+ "%lu: Sample out of range, max %lu",
+ (unsigned long) sample, (unsigned long) td->td_samplesperpixel);
+ return ((tstrip_t) 0);
+ }
+ strip += sample*td->td_stripsperimage;
+ }
+ return (strip);
+}
+
+/*
+ * Compute how many strips are in an image.
+ */
+tstrip_t
+TIFFNumberOfStrips(TIFF* tif)
+{
+ TIFFDirectory *td = &tif->tif_dir;
+ tstrip_t nstrips;
+
+ nstrips = (td->td_rowsperstrip == (uint32) -1 ? 1 :
+ TIFFhowmany(td->td_imagelength, td->td_rowsperstrip));
+ if (td->td_planarconfig == PLANARCONFIG_SEPARATE)
+ nstrips = multiply(tif, nstrips, td->td_samplesperpixel,
+ "TIFFNumberOfStrips");
+ return (nstrips);
+}
+
+/*
+ * Compute the # bytes in a variable height, row-aligned strip.
+ */
+tsize_t
+TIFFVStripSize(TIFF* tif, uint32 nrows)
+{
+ TIFFDirectory *td = &tif->tif_dir;
+
+ if (nrows == (uint32) -1)
+ nrows = td->td_imagelength;
+ if (td->td_planarconfig == PLANARCONFIG_CONTIG &&
+ td->td_photometric == PHOTOMETRIC_YCBCR &&
+ !isUpSampled(tif)) {
+ /*
+ * Packed YCbCr data contain one Cb+Cr for every
+ * HorizontalSampling*VerticalSampling Y values.
+ * Must also roundup width and height when calculating
+ * since images that are not a multiple of the
+ * horizontal/vertical subsampling area include
+ * YCbCr data for the extended image.
+ */
+ uint16 ycbcrsubsampling[2];
+ tsize_t w, scanline, samplingarea;
+
+ TIFFGetField( tif, TIFFTAG_YCBCRSUBSAMPLING,
+ ycbcrsubsampling + 0,
+ ycbcrsubsampling + 1 );
+
+ samplingarea = ycbcrsubsampling[0]*ycbcrsubsampling[1];
+ if (samplingarea == 0) {
+ TIFFError(tif->tif_name, "Invalid YCbCr subsampling");
+ return 0;
+ }
+
+ w = TIFFroundup(td->td_imagewidth, ycbcrsubsampling[0]);
+ scanline = TIFFhowmany8(multiply(tif, w, td->td_bitspersample,
+ "TIFFVStripSize"));
+ nrows = TIFFroundup(nrows, ycbcrsubsampling[1]);
+ /* NB: don't need TIFFhowmany here 'cuz everything is rounded */
+ scanline = multiply(tif, nrows, scanline, "TIFFVStripSize");
+ return ((tsize_t)
+ summarize(tif, scanline,
+ multiply(tif, 2, scanline / samplingarea,
+ "TIFFVStripSize"), "TIFFVStripSize"));
+ } else
+ return ((tsize_t) multiply(tif, nrows, TIFFScanlineSize(tif),
+ "TIFFVStripSize"));
+}
+
+
+/*
+ * Compute the # bytes in a raw strip.
+ */
+tsize_t
+TIFFRawStripSize(TIFF* tif, tstrip_t strip)
+{
+ TIFFDirectory* td = &tif->tif_dir;
+ tsize_t bytecount = td->td_stripbytecount[strip];
+
+ if (bytecount <= 0) {
+ TIFFError(tif->tif_name,
+ "%lu: Invalid strip byte count, strip %lu",
+ (unsigned long) bytecount, (unsigned long) strip);
+ bytecount = (tsize_t) -1;
+ }
+
+ return bytecount;
+}
+
+/*
+ * Compute the # bytes in a (row-aligned) strip.
+ *
+ * Note that if RowsPerStrip is larger than the
+ * recorded ImageLength, then the strip size is
+ * truncated to reflect the actual space required
+ * to hold the strip.
+ */
+tsize_t
+TIFFStripSize(TIFF* tif)
+{
+ TIFFDirectory* td = &tif->tif_dir;
+ uint32 rps = td->td_rowsperstrip;
+ if (rps > td->td_imagelength)
+ rps = td->td_imagelength;
+ return (TIFFVStripSize(tif, rps));
+}
+
+/*
+ * Compute a default strip size based on the image
+ * characteristics and a requested value. If the
+ * request is <1 then we choose a strip size according
+ * to certain heuristics.
+ */
+uint32
+TIFFDefaultStripSize(TIFF* tif, uint32 request)
+{
+ return (*tif->tif_defstripsize)(tif, request);
+}
+
+uint32
+_TIFFDefaultStripSize(TIFF* tif, uint32 s)
+{
+ if ((int32) s < 1) {
+ /*
+ * If RowsPerStrip is unspecified, try to break the
+ * image up into strips that are approximately 8Kbytes.
+ */
+ tsize_t scanline = TIFFScanlineSize(tif);
+ s = (uint32)(8*1024) / (scanline == 0 ? 1 : scanline);
+ if (s == 0) /* very wide images */
+ s = 1;
+ }
+ return (s);
+}
+
+/*
+ * Return the number of bytes to read/write in a call to
+ * one of the scanline-oriented i/o routines. Note that
+ * this number may be 1/samples-per-pixel if data is
+ * stored as separate planes.
+ */
+tsize_t
+TIFFScanlineSize(TIFF* tif)
+{
+ TIFFDirectory *td = &tif->tif_dir;
+ tsize_t scanline;
+
+ scanline = multiply (tif, td->td_bitspersample, td->td_imagewidth,
+ "TIFFScanlineSize");
+ if (td->td_planarconfig == PLANARCONFIG_CONTIG)
+ scanline = multiply (tif, scanline, td->td_samplesperpixel,
+ "TIFFScanlineSize");
+ return ((tsize_t) TIFFhowmany8(scanline));
+}
+
+/*
+ * Return the number of bytes required to store a complete
+ * decoded and packed raster scanline (as opposed to the
+ * I/O size returned by TIFFScanlineSize which may be less
+ * if data is store as separate planes).
+ */
+tsize_t
+TIFFRasterScanlineSize(TIFF* tif)
+{
+ TIFFDirectory *td = &tif->tif_dir;
+ tsize_t scanline;
+
+ scanline = multiply (tif, td->td_bitspersample, td->td_imagewidth,
+ "TIFFRasterScanlineSize");
+ if (td->td_planarconfig == PLANARCONFIG_CONTIG) {
+ scanline = multiply (tif, scanline, td->td_samplesperpixel,
+ "TIFFRasterScanlineSize");
+ return ((tsize_t) TIFFhowmany8(scanline));
+ } else
+ return ((tsize_t) multiply (tif, TIFFhowmany8(scanline),
+ td->td_samplesperpixel,
+ "TIFFRasterScanlineSize"));
+}
+
+/* vim: set ts=8 sts=8 sw=8 noet: */
projects / opencv / blobdiff