| /* $Header: /cvsroot/osrs/libtiff/libtiff/tif_strip.c,v 1.1.1.1 1999/07/27 21:50:27 mike 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" |
| |
| /* |
| * 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, |
| "%u: Sample out of range, max %u", |
| sample, 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 ? |
| (td->td_imagelength != 0 ? 1 : 0) : |
| TIFFhowmany(td->td_imagelength, td->td_rowsperstrip)); |
| if (td->td_planarconfig == PLANARCONFIG_SEPARATE) |
| nstrips *= td->td_samplesperpixel; |
| 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; |
| #ifdef YCBCR_SUPPORT |
| 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. |
| */ |
| tsize_t w = |
| TIFFroundup(td->td_imagewidth, td->td_ycbcrsubsampling[0]); |
| tsize_t scanline = TIFFhowmany(w*td->td_bitspersample, 8); |
| tsize_t samplingarea = |
| td->td_ycbcrsubsampling[0]*td->td_ycbcrsubsampling[1]; |
| nrows = TIFFroundup(nrows, td->td_ycbcrsubsampling[1]); |
| /* NB: don't need TIFFhowmany here 'cuz everything is rounded */ |
| return ((tsize_t) |
| (nrows*scanline + 2*(nrows*scanline / samplingarea))); |
| } else |
| #endif |
| return ((tsize_t)(nrows * TIFFScanlineSize(tif))); |
| } |
| |
| /* |
| * 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 = td->td_bitspersample * td->td_imagewidth; |
| if (td->td_planarconfig == PLANARCONFIG_CONTIG) |
| scanline *= td->td_samplesperpixel; |
| return ((tsize_t) TIFFhowmany(scanline, 8)); |
| } |
| |
| /* |
| * 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 = td->td_bitspersample * td->td_imagewidth; |
| if (td->td_planarconfig == PLANARCONFIG_CONTIG) { |
| scanline *= td->td_samplesperpixel; |
| return ((tsize_t) TIFFhowmany(scanline, 8)); |
| } else |
| return ((tsize_t) |
| TIFFhowmany(scanline, 8)*td->td_samplesperpixel); |
| } |