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Move libimagequant implementation into cpp so that <libimagequant.h> header does not need to be distributed.

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This commit is contained in:
Daniel Patterson 2015-05-26 11:57:33 -07:00
parent 5970301a3c
commit 41f032760d
3 changed files with 131 additions and 88 deletions
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89
include/mapnik/png_io.hpp
View file

@ -39,7 +39,6 @@
extern "C"
{
#include <png.h>
#include <libimagequant.h>
}
#define MAX_OCTREE_LEVELS 4
@ -712,96 +711,10 @@ void save_as_png8_pal(T1 & file,
save_as_png8<T1, T2, rgba_palette>(file, image, pal, pal.palette(), pal.alphaTable(), opts);
}
// TODO: This only works with rgba8_t image types
template <typename T1, typename T2>
void save_as_png8_libimagequant(T1 & file,
T2 const& image,
png_options const& opts)
{
unsigned width = image.width();
unsigned height = image.height();
uint32_t *buf[height];
// TODO: this won't work on big-endian architectures, liq expects data in RGBA byte order
for (size_t y = 0; y < height; ++y)
{
buf[y] = (uint32_t *)image.get_row(y);
}
// Set up libimagequant
liq_attr *attr = liq_attr_create();
liq_set_speed(attr, opts.iq_speed);
liq_image *liq_image = liq_image_create_rgba_rows(attr, (void **)buf, width, height, 0);
// Do the quantization
liq_result *res = liq_quantize_image(attr, liq_image);
if (opts.iq_dither != -1)
{
liq_set_dithering_level(res, opts.iq_dither);
}
if (opts.gamma > 0)
{
liq_set_output_gamma(res, opts.gamma);
}
// Extract the generated 8-bit imag
image_gray8 quantized_image(width, height);
liq_write_remapped_image(res, liq_image, (void *)quantized_image.data(), width*height*sizeof(gray8_t));
// Extract the generated palette and alpha vector from libimagequant
std::vector<mapnik::rgb> palette;
std::vector<unsigned> alpha;
const liq_palette *liq_pal = liq_get_palette(res);
for (int i = 0; i < liq_pal->count; ++i)
{
palette.push_back({ liq_pal->entries[i].r, liq_pal->entries[i].g, liq_pal->entries[i].b });
alpha.push_back(liq_pal->entries[i].a);
}
// Encode the image, using a bit-depth depending on the number of colors in the generated
// palette
if (palette.size() > 16) // 8-bit encoding
{
save_as_png(file, palette, quantized_image, width, height, 8, alpha, opts);
}
else if (palette.size() > 1) // up to 16 colors, 4-bit encoding
{
unsigned image_width = ((width + 7) >> 1) & ~3U; // 4-bit image, round up to 32-bit boundary
unsigned image_height = height;
image_gray8 reduced_image(image_width, image_height);
for (unsigned y = 0; y < height; ++y)
{
mapnik::image_gray8::pixel_type const * row = quantized_image.get_row(y);
mapnik::image_gray8::pixel_type * row_out = reduced_image.get_row(y);
std::uint8_t index = 0;
for (unsigned x = 0; x < width; ++x)
{
index = row[x];
if (x%2 == 0)
{
index = index<<4;
}
row_out[x>>1] |= index;
}
}
save_as_png(file, palette, reduced_image, width, height, 4, alpha, opts);
}
else // 1 color, 1-bit encoding
{
unsigned image_width = ((width + 15) >> 3) & ~1U; // 1-bit image, round up to 16-bit boundary
unsigned image_height = height;
image_gray8 reduced_image(image_width, image_height);
reduced_image.set(0);
save_as_png(file, palette, reduced_image, width, height, 1, alpha, opts);
}
// Cleanup libimagequant
liq_attr_destroy(attr);
liq_image_destroy(liq_image);
liq_result_destroy(res);
}
png_options const& opts);
}

1
src/build.py
View file

@ -253,6 +253,7 @@ source = Split(
renderer_common/render_pattern.cpp
renderer_common/process_group_symbolizer.cpp
math.cpp
png_io.cpp
"""
)

129
src/png_io.cpp Normal file
View file

@ -0,0 +1,129 @@
/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2014 Daniel Patterson
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
// mapnik
#include <mapnik/png_io.hpp>
extern "C"
{
#include <libimagequant.h>
}
namespace mapnik
{
// Note: This only works with rgba8_t image types
template <typename T1, typename T2>
void save_as_png8_libimagequant(T1 & file,
T2 const& image,
png_options const& opts)
{
unsigned width = image.width();
unsigned height = image.height();
uint32_t *buf[height];
// TODO: this won't work on big-endian architectures, liq expects data in RGBA byte order
for (size_t y = 0; y < height; ++y)
{
buf[y] = (uint32_t *)image.get_row(y);
}
// Set up libimagequant
liq_attr *attr = liq_attr_create();
liq_set_speed(attr, opts.iq_speed);
liq_image *liq_image = liq_image_create_rgba_rows(attr, (void **)buf, width, height, 0);
// Do the quantization
liq_result *res = liq_quantize_image(attr, liq_image);
if (opts.iq_dither != -1)
{
liq_set_dithering_level(res, opts.iq_dither);
}
if (opts.gamma > 0)
{
liq_set_output_gamma(res, opts.gamma);
}
// Extract the generated 8-bit imag
image_gray8 quantized_image(width, height);
liq_write_remapped_image(res, liq_image, (void *)quantized_image.data(), width*height*sizeof(gray8_t));
// Extract the generated palette and alpha vector from libimagequant
std::vector<mapnik::rgb> palette;
std::vector<unsigned> alpha;
const liq_palette *liq_pal = liq_get_palette(res);
for (int i = 0; i < liq_pal->count; ++i)
{
palette.push_back({ liq_pal->entries[i].r, liq_pal->entries[i].g, liq_pal->entries[i].b });
alpha.push_back(liq_pal->entries[i].a);
}
// Encode the image, using a bit-depth depending on the number of colors in the generated
// palette
if (palette.size() > 16) // 8-bit encoding
{
save_as_png(file, palette, quantized_image, width, height, 8, alpha, opts);
}
else if (palette.size() > 1) // up to 16 colors, 4-bit encoding
{
unsigned image_width = ((width + 7) >> 1) & ~3U; // 4-bit image, round up to 32-bit boundary
unsigned image_height = height;
image_gray8 reduced_image(image_width, image_height);
for (unsigned y = 0; y < height; ++y)
{
mapnik::image_gray8::pixel_type const * row = quantized_image.get_row(y);
mapnik::image_gray8::pixel_type * row_out = reduced_image.get_row(y);
std::uint8_t index = 0;
for (unsigned x = 0; x < width; ++x)
{
index = row[x];
if (x%2 == 0)
{
index = index<<4;
}
row_out[x>>1] |= index;
}
}
save_as_png(file, palette, reduced_image, width, height, 4, alpha, opts);
}
else // 1 color, 1-bit encoding
{
unsigned image_width = ((width + 15) >> 3) & ~1U; // 1-bit image, round up to 16-bit boundary
unsigned image_height = height;
image_gray8 reduced_image(image_width, image_height);
reduced_image.set(0);
save_as_png(file, palette, reduced_image, width, height, 1, alpha, opts);
}
// Cleanup libimagequant
liq_attr_destroy(attr);
liq_image_destroy(liq_image);
liq_result_destroy(res);
}
// Both image_view and image expose a get_row(), so we can support both parameter types
template void save_as_png8_libimagequant(std::ostream &, mapnik::image_view<mapnik::image<mapnik::rgba8_t>> const&, png_options const&);
template void save_as_png8_libimagequant(std::ostream &, mapnik::image<mapnik::rgba8_t> const&, png_options const&);
}