709 lines
22 KiB
C++
709 lines
22 KiB
C++
/*****************************************************************************
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*
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* This file is part of Mapnik (c++ mapping toolkit)
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*
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* Copyright (C) 2014 Artem Pavlenko
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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*****************************************************************************/
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#ifndef MAPNIK_PNG_IO_HPP
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#define MAPNIK_PNG_IO_HPP
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// mapnik
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#include <mapnik/palette.hpp>
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#include <mapnik/octree.hpp>
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#include <mapnik/hextree.hpp>
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#include <mapnik/miniz_png.hpp>
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#include <mapnik/image_data.hpp>
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// zlib
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#include <zlib.h> // for Z_DEFAULT_COMPRESSION
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// boost
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extern "C"
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{
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#include <png.h>
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}
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#define MAX_OCTREE_LEVELS 4
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namespace mapnik {
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struct png_options {
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int colors;
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int compression;
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int strategy;
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int trans_mode;
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double gamma;
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bool paletted;
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bool use_hextree;
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bool use_miniz;
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png_options() :
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colors(256),
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compression(Z_DEFAULT_COMPRESSION),
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strategy(Z_DEFAULT_STRATEGY),
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trans_mode(-1),
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gamma(-1),
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paletted(true),
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use_hextree(true),
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use_miniz(false) {}
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};
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template <typename T>
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void write_data (png_structp png_ptr, png_bytep data, png_size_t length)
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{
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T * out = static_cast<T*>(png_get_io_ptr(png_ptr));
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out->write(reinterpret_cast<char*>(data), length);
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}
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template <typename T>
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void flush_data (png_structp png_ptr)
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{
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T * out = static_cast<T*>(png_get_io_ptr(png_ptr));
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out->flush();
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}
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template <typename T1, typename T2>
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void save_as_png(T1 & file,
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T2 const& image,
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png_options const& opts)
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{
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if (opts.use_miniz)
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{
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MiniZ::PNGWriter writer(opts.compression,opts.strategy);
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if (opts.trans_mode == 0)
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{
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writer.writeIHDR(image.width(), image.height(), 24);
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writer.writeIDATStripAlpha(image);
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}
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else
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{
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writer.writeIHDR(image.width(), image.height(), 32);
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writer.writeIDAT(image);
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}
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writer.writeIEND();
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writer.toStream(file);
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return;
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}
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png_voidp error_ptr=0;
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png_structp png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING,
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error_ptr,0, 0);
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if (!png_ptr) return;
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// switch on optimization only if supported
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#if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200) && defined(PNG_MMX_CODE_SUPPORTED)
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png_uint_32 mask, flags;
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flags = png_get_asm_flags(png_ptr);
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mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
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png_set_asm_flags(png_ptr, flags | mask);
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#endif
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png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_FILTER_NONE);
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png_infop info_ptr = png_create_info_struct(png_ptr);
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if (!info_ptr)
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{
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png_destroy_write_struct(&png_ptr,(png_infopp)0);
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return;
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}
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jmp_buf* jmp_context = (jmp_buf*) png_get_error_ptr(png_ptr);
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if (jmp_context)
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{
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png_destroy_write_struct(&png_ptr, &info_ptr);
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return;
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}
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png_set_write_fn (png_ptr, &file, &write_data<T1>, &flush_data<T1>);
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png_set_compression_level(png_ptr, opts.compression);
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png_set_compression_strategy(png_ptr, opts.strategy);
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png_set_compression_buffer_size(png_ptr, 32768);
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png_set_IHDR(png_ptr, info_ptr,image.width(),image.height(),8,
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(opts.trans_mode == 0) ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA,PNG_INTERLACE_NONE,
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PNG_COMPRESSION_TYPE_DEFAULT,PNG_FILTER_TYPE_DEFAULT);
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const std::unique_ptr<png_bytep[]> row_pointers(new png_bytep[image.height()]);
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for (unsigned int i = 0; i < image.height(); i++)
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{
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row_pointers[i] = (png_bytep)image.getRow(i);
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}
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png_set_rows(png_ptr, info_ptr, row_pointers.get());
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png_write_png(png_ptr, info_ptr, (opts.trans_mode == 0) ? PNG_TRANSFORM_STRIP_FILLER_AFTER : PNG_TRANSFORM_IDENTITY, nullptr);
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png_destroy_write_struct(&png_ptr, &info_ptr);
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}
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template <typename T>
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void reduce_8(T const& in,
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image_data_8 & out,
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octree<rgb> trees[],
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unsigned limits[],
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unsigned levels,
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std::vector<unsigned> & alpha)
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{
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unsigned width = in.width();
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unsigned height = in.height();
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std::vector<unsigned> alphaCount(alpha.size());
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for(unsigned i=0; i<alpha.size(); i++)
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{
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alpha[i] = 0;
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alphaCount[i] = 0;
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}
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for (unsigned y = 0; y < height; ++y)
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{
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mapnik::image_data_32::pixel_type const * row = in.getRow(y);
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mapnik::image_data_8::pixel_type * row_out = out.getRow(y);
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for (unsigned x = 0; x < width; ++x)
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{
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unsigned val = row[x];
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byte index = 0;
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int idx = -1;
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for(int j=levels-1; j>0; j--)
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{
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if (U2ALPHA(val)>=limits[j] && trees[j].colors()>0)
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{
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index = idx = trees[j].quantize(val);
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break;
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}
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}
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if (idx>=0 && idx<(int)alpha.size())
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{
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alpha[idx]+=U2ALPHA(val);
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alphaCount[idx]++;
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}
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row_out[x] = index;
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}
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}
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for(unsigned i=0; i<alpha.size(); i++)
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{
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if (alphaCount[i]!=0)
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{
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alpha[i] /= alphaCount[i];
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}
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}
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}
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template <typename T>
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void reduce_4(T const& in,
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image_data_8 & out,
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octree<rgb> trees[],
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unsigned limits[],
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unsigned levels,
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std::vector<unsigned> & alpha)
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{
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unsigned width = in.width();
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unsigned height = in.height();
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std::vector<unsigned> alphaCount(alpha.size());
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for(unsigned i=0; i<alpha.size(); i++)
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{
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alpha[i] = 0;
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alphaCount[i] = 0;
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}
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for (unsigned y = 0; y < height; ++y)
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{
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mapnik::image_data_32::pixel_type const * row = in.getRow(y);
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mapnik::image_data_8::pixel_type * row_out = out.getRow(y);
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for (unsigned x = 0; x < width; ++x)
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{
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unsigned val = row[x];
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byte index = 0;
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int idx=-1;
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for(int j=levels-1; j>0; j--)
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{
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if (U2ALPHA(val)>=limits[j] && trees[j].colors()>0)
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{
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index = idx = trees[j].quantize(val);
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break;
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}
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}
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if (idx>=0 && idx<(int)alpha.size())
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{
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alpha[idx]+=U2ALPHA(val);
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alphaCount[idx]++;
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}
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if (x%2 == 0)
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{
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index = index<<4;
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}
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row_out[x>>1] |= index;
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}
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}
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for(unsigned i=0; i<alpha.size(); i++)
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{
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if (alphaCount[i]!=0)
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{
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alpha[i] /= alphaCount[i];
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}
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}
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}
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// 1-bit but only one color.
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template <typename T>
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void reduce_1(T const&,
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image_data_8 & out,
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octree<rgb> /*trees*/[],
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unsigned /*limits*/[],
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std::vector<unsigned> & /*alpha*/)
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{
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out.set(0); // only one color!!!
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}
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template <typename T>
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void save_as_png(T & file, std::vector<mapnik::rgb> const& palette,
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mapnik::image_data_8 const& image,
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unsigned width,
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unsigned height,
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unsigned color_depth,
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std::vector<unsigned> const&alpha,
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png_options const& opts)
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{
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if (opts.use_miniz)
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{
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MiniZ::PNGWriter writer(opts.compression,opts.strategy);
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// image.width()/height() does not reflect the actual image dimensions; it
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// refers to the quantized scanlines.
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writer.writeIHDR(width, height, color_depth);
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writer.writePLTE(palette);
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writer.writetRNS(alpha);
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writer.writeIDAT(image);
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writer.writeIEND();
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writer.toStream(file);
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return;
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}
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png_voidp error_ptr=0;
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png_structp png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING,
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error_ptr,0, 0);
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if (!png_ptr)
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{
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return;
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}
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// switch on optimization only if supported
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#if defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200) && defined(PNG_MMX_CODE_SUPPORTED)
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png_uint_32 mask, flags;
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flags = png_get_asm_flags(png_ptr);
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mask = png_get_asm_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE);
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png_set_asm_flags(png_ptr, flags | mask);
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#endif
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png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_FILTER_NONE);
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png_infop info_ptr = png_create_info_struct(png_ptr);
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if (!info_ptr)
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{
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png_destroy_write_struct(&png_ptr,(png_infopp)0);
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return;
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}
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jmp_buf* jmp_context = (jmp_buf*) png_get_error_ptr(png_ptr);
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if (jmp_context)
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{
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png_destroy_write_struct(&png_ptr, &info_ptr);
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return;
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}
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png_set_write_fn (png_ptr, &file, &write_data<T>, &flush_data<T>);
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png_set_compression_level(png_ptr, opts.compression);
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png_set_compression_strategy(png_ptr, opts.strategy);
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png_set_compression_buffer_size(png_ptr, 32768);
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png_set_IHDR(png_ptr, info_ptr,width,height,color_depth,
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PNG_COLOR_TYPE_PALETTE,PNG_INTERLACE_NONE,
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PNG_COMPRESSION_TYPE_DEFAULT,PNG_FILTER_TYPE_DEFAULT);
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png_color* pal = const_cast<png_color*>(reinterpret_cast<const png_color*>(&palette[0]));
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png_set_PLTE(png_ptr, info_ptr, pal, static_cast<unsigned>(palette.size()));
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// make transparent lowest indexes, so tRNS is small
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if (alpha.size()>0)
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{
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std::vector<png_byte> trans(alpha.size());
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unsigned alphaSize=0;//truncate to nonopaque values
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for(unsigned i=0; i < alpha.size(); i++)
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{
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trans[i]=alpha[i];
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if (alpha[i]<255)
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{
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alphaSize = i+1;
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}
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}
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if (alphaSize>0)
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{
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png_set_tRNS(png_ptr, info_ptr, (png_bytep)&trans[0], alphaSize, 0);
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}
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}
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png_write_info(png_ptr, info_ptr);
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for (unsigned i=0;i<height;i++)
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{
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png_write_row(png_ptr,(png_bytep)image.getRow(i));
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}
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png_write_end(png_ptr, info_ptr);
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png_destroy_write_struct(&png_ptr, &info_ptr);
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}
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template <typename T1,typename T2>
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void save_as_png8_oct(T1 & file,
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T2 const& image,
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png_options const& opts)
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{
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// number of alpha ranges in png8 format; 2 results in smallest image with binary transparency
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// 3 is minimum for semitransparency, 4 is recommended, anything else is worse
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const unsigned TRANSPARENCY_LEVELS = (opts.trans_mode==2||opts.trans_mode<0)?MAX_OCTREE_LEVELS:2;
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unsigned width = image.width();
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unsigned height = image.height();
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unsigned alphaHist[256];//transparency histogram
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unsigned semiCount = 0;//sum of semitransparent pixels
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unsigned meanAlpha = 0;
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if (opts.trans_mode == 0)
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{
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meanAlpha = 255;
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}
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else
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{
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for(int i=0; i<256; i++)
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{
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alphaHist[i] = 0;
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}
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for (unsigned y = 0; y < height; ++y)
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{
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for (unsigned x = 0; x < width; ++x)
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{
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unsigned val = U2ALPHA((unsigned)image.getRow(y)[x]);
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alphaHist[val]++;
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meanAlpha += val;
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if (val>0 && val<255)
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{
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semiCount++;
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}
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}
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}
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meanAlpha /= width*height;
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}
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// transparency ranges division points
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unsigned limits[MAX_OCTREE_LEVELS+1];
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limits[0] = 0;
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limits[1] = (opts.trans_mode!=0 && alphaHist[0]>0)?1:0;
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limits[TRANSPARENCY_LEVELS] = 256;
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for(unsigned j=2; j<TRANSPARENCY_LEVELS; j++)
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{
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limits[j] = limits[1];
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}
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if (opts.trans_mode != 0)
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{
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unsigned alphaHistSum = 0;
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for(unsigned i=1; i<256; i++)
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{
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alphaHistSum += alphaHist[i];
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for(unsigned j=1; j<TRANSPARENCY_LEVELS; j++)
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{
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if (alphaHistSum<semiCount*(j)/4)
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{
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limits[j] = i;
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}
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}
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}
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}
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// avoid too wide full transparent range
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if (limits[1]>256/(TRANSPARENCY_LEVELS-1))
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{
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limits[1]=256/(TRANSPARENCY_LEVELS-1);
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}
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// avoid too wide full opaque range
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if (limits[TRANSPARENCY_LEVELS-1]<212)
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{
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limits[TRANSPARENCY_LEVELS-1]=212;
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}
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if (TRANSPARENCY_LEVELS==2)
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{
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limits[1]=127;
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}
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// estimated number of colors from palette assigned to chosen ranges
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unsigned cols[MAX_OCTREE_LEVELS];
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// count colors
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if (opts.trans_mode == 0)
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{
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for (unsigned j=0; j<TRANSPARENCY_LEVELS; j++)
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{
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cols[j] = 0;
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}
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cols[TRANSPARENCY_LEVELS-1] = width * height;
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}
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else
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{
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for (unsigned j=0; j<TRANSPARENCY_LEVELS; j++)
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{
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cols[j] = 0;
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for (unsigned i=limits[j]; i<limits[j+1]; i++)
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{
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cols[j] += alphaHist[i];
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}
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}
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}
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unsigned divCoef = width*height-cols[0];
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if (divCoef==0)
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{
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divCoef = 1;
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}
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cols[0] = cols[0]>0?1:0; // fully transparent color (one or not at all)
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if (opts.colors>=64)
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{
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// give chance less populated but not empty cols to have at least few colors(12)
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unsigned minCols = (12+1)*divCoef/(opts.colors-cols[0]);
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for(unsigned j=1; j<TRANSPARENCY_LEVELS; j++)
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{
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if (cols[j]>12 && cols[j]<minCols)
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{
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divCoef += minCols-cols[j];
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cols[j] = minCols;
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}
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}
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}
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unsigned usedColors = cols[0];
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for(unsigned j=1; j<TRANSPARENCY_LEVELS-1; j++)
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{
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cols[j] = cols[j]*(opts.colors-cols[0])/divCoef;
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usedColors += cols[j];
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}
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// use rest for most opaque group of pixels
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cols[TRANSPARENCY_LEVELS-1] = opts.colors-usedColors;
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//no transparency
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if (opts.trans_mode == 0)
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{
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limits[1] = 0;
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cols[0] = 0;
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cols[1] = opts.colors;
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}
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// octree table for separate alpha range with 1-based index (0 is fully transparent: no color)
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octree<rgb> trees[MAX_OCTREE_LEVELS];
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for(unsigned j=1; j<TRANSPARENCY_LEVELS; j++)
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{
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trees[j].setMaxColors(cols[j]);
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}
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for (unsigned y = 0; y < height; ++y)
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{
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typename T2::pixel_type const * row = image.getRow(y);
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for (unsigned x = 0; x < width; ++x)
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{
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unsigned val = row[x];
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// insert to proper tree based on alpha range
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|
for(unsigned j=TRANSPARENCY_LEVELS-1; j>0; j--)
|
|
{
|
|
if (cols[j]>0 && U2ALPHA(val)>=limits[j])
|
|
{
|
|
trees[j].insert(mapnik::rgb(U2RED(val), U2GREEN(val), U2BLUE(val)));
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
unsigned leftovers = 0;
|
|
std::vector<rgb> palette;
|
|
palette.reserve(opts.colors);
|
|
if (cols[0])
|
|
{
|
|
palette.push_back(rgb(0,0,0));
|
|
}
|
|
|
|
for(unsigned j=1; j<TRANSPARENCY_LEVELS; j++)
|
|
{
|
|
if (cols[j]>0)
|
|
{
|
|
if (leftovers>0)
|
|
{
|
|
cols[j] += leftovers;
|
|
trees[j].setMaxColors(cols[j]);
|
|
leftovers = 0;
|
|
}
|
|
std::vector<rgb> pal;
|
|
trees[j].setOffset( static_cast<unsigned>(palette.size()));
|
|
trees[j].create_palette(pal);
|
|
leftovers = cols[j] - static_cast<unsigned>(pal.size());
|
|
cols[j] = static_cast<unsigned>(pal.size());
|
|
palette.insert(palette.begin(), pal.begin(), pal.end());
|
|
}
|
|
}
|
|
|
|
//transparency values per palette index
|
|
std::vector<unsigned> alphaTable;
|
|
//alphaTable.resize(palette.size());//allow semitransparency also in almost opaque range
|
|
if (opts.trans_mode != 0)
|
|
{
|
|
alphaTable.resize(palette.size() - cols[TRANSPARENCY_LEVELS-1]);
|
|
}
|
|
|
|
if (palette.size() > 16 )
|
|
{
|
|
// >16 && <=256 colors -> write 8-bit color depth
|
|
image_data_8 reduced_image(width,height);
|
|
reduce_8(image, reduced_image, trees, limits, TRANSPARENCY_LEVELS, alphaTable);
|
|
save_as_png(file,palette,reduced_image,width,height,8,alphaTable,opts);
|
|
}
|
|
else if (palette.size() == 1)
|
|
{
|
|
// 1 color image -> write 1-bit color depth PNG
|
|
unsigned image_width = ((width + 15) >> 3) & ~1U; // 1-bit image, round up to 16-bit boundary
|
|
unsigned image_height = height;
|
|
image_data_8 reduced_image(image_width,image_height);
|
|
reduce_1(image,reduced_image,trees, limits, alphaTable);
|
|
if (meanAlpha<255 && cols[0]==0)
|
|
{
|
|
alphaTable.resize(1);
|
|
alphaTable[0] = meanAlpha;
|
|
}
|
|
save_as_png(file,palette,reduced_image,width,height,1,alphaTable,opts);
|
|
}
|
|
else
|
|
{
|
|
// <=16 colors -> write 4-bit color depth PNG
|
|
unsigned image_width = ((width + 7) >> 1) & ~3U; // 4-bit image, round up to 32-bit boundary
|
|
unsigned image_height = height;
|
|
image_data_8 reduced_image(image_width,image_height);
|
|
reduce_4(image, reduced_image, trees, limits, TRANSPARENCY_LEVELS, alphaTable);
|
|
save_as_png(file,palette,reduced_image,width,height,4,alphaTable,opts);
|
|
}
|
|
}
|
|
|
|
|
|
template <typename T1, typename T2, typename T3>
|
|
void save_as_png8(T1 & file,
|
|
T2 const& image,
|
|
T3 const & tree,
|
|
std::vector<mapnik::rgb> const& palette,
|
|
std::vector<unsigned> const& alphaTable,
|
|
png_options const& opts)
|
|
{
|
|
unsigned width = image.width();
|
|
unsigned height = image.height();
|
|
|
|
if (palette.size() > 16 )
|
|
{
|
|
// >16 && <=256 colors -> write 8-bit color depth
|
|
image_data_8 reduced_image(width, height);
|
|
for (unsigned y = 0; y < height; ++y)
|
|
{
|
|
mapnik::image_data_32::pixel_type const * row = image.getRow(y);
|
|
mapnik::image_data_8::pixel_type * row_out = reduced_image.getRow(y);
|
|
for (unsigned x = 0; x < width; ++x)
|
|
{
|
|
row_out[x] = tree.quantize(row[x]);
|
|
}
|
|
}
|
|
save_as_png(file, palette, reduced_image, width, height, 8, alphaTable, opts);
|
|
}
|
|
else if (palette.size() == 1)
|
|
{
|
|
// 1 color image -> write 1-bit color depth PNG
|
|
unsigned image_width = ((width + 15) >> 3) & ~1U; // 1-bit image, round up to 16-bit boundary
|
|
unsigned image_height = height;
|
|
image_data_8 reduced_image(image_width, image_height);
|
|
reduced_image.set(0);
|
|
save_as_png(file, palette, reduced_image, width, height, 1, alphaTable, opts);
|
|
}
|
|
else
|
|
{
|
|
// <=16 colors -> write 4-bit color depth PNG
|
|
unsigned image_width = ((width + 7) >> 1) & ~3U; // 4-bit image, round up to 32-bit boundary
|
|
unsigned image_height = height;
|
|
image_data_8 reduced_image(image_width, image_height);
|
|
for (unsigned y = 0; y < height; ++y)
|
|
{
|
|
mapnik::image_data_32::pixel_type const * row = image.getRow(y);
|
|
mapnik::image_data_8::pixel_type * row_out = reduced_image.getRow(y);
|
|
byte index = 0;
|
|
for (unsigned x = 0; x < width; ++x)
|
|
{
|
|
|
|
index = tree.quantize(row[x]);
|
|
if (x%2 == 0)
|
|
{
|
|
index = index<<4;
|
|
}
|
|
row_out[x>>1] |= index;
|
|
}
|
|
}
|
|
save_as_png(file, palette, reduced_image, width, height, 4, alphaTable, opts);
|
|
}
|
|
}
|
|
|
|
template <typename T1,typename T2>
|
|
void save_as_png8_hex(T1 & file,
|
|
T2 const& image,
|
|
png_options const& opts)
|
|
{
|
|
unsigned width = image.width();
|
|
unsigned height = image.height();
|
|
if (width + height > 3) // at least 3 pixels (hextree implementation requirement)
|
|
{
|
|
// structure for color quantization
|
|
hextree<mapnik::rgba> tree(opts.colors);
|
|
if (opts.trans_mode >= 0)
|
|
{
|
|
tree.setTransMode(opts.trans_mode);
|
|
}
|
|
if (opts.gamma > 0)
|
|
{
|
|
tree.setGamma(opts.gamma);
|
|
}
|
|
|
|
for (unsigned y = 0; y < height; ++y)
|
|
{
|
|
typename T2::pixel_type const * row = image.getRow(y);
|
|
for (unsigned x = 0; x < width; ++x)
|
|
{
|
|
unsigned val = row[x];
|
|
tree.insert(mapnik::rgba(U2RED(val), U2GREEN(val), U2BLUE(val), U2ALPHA(val)));
|
|
}
|
|
}
|
|
|
|
//transparency values per palette index
|
|
std::vector<mapnik::rgba> pal;
|
|
tree.create_palette(pal);
|
|
std::vector<mapnik::rgb> palette;
|
|
std::vector<unsigned> alphaTable;
|
|
for (unsigned i=0; i<pal.size(); ++i)
|
|
{
|
|
palette.push_back(rgb(pal[i].r, pal[i].g, pal[i].b));
|
|
alphaTable.push_back(pal[i].a);
|
|
}
|
|
save_as_png8<T1, T2, hextree<mapnik::rgba> >(file, image, tree, palette, alphaTable, opts);
|
|
}
|
|
else
|
|
{
|
|
throw std::runtime_error("Can't quantize images with less than 3 pixels");
|
|
}
|
|
}
|
|
|
|
template <typename T1, typename T2>
|
|
void save_as_png8_pal(T1 & file,
|
|
T2 const& image,
|
|
rgba_palette const& pal,
|
|
png_options const& opts)
|
|
{
|
|
save_as_png8<T1, T2, rgba_palette>(file, image, pal, pal.palette(), pal.alphaTable(), opts);
|
|
}
|
|
|
|
}
|
|
|
|
#endif // MAPNIK_PNG_IO_HPP
|