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hextree - avoid quantizing images with less than 3 pixels (hextree implementation requirement)

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This commit is contained in:
artemp 2014-08-21 12:43:43 +01:00
parent a4cd4821a0
commit 8db68fc5e3
1 changed files with 33 additions and 28 deletions
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61
include/mapnik/png_io.hpp
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@ -654,40 +654,45 @@ void save_as_png8_hex(T1 & file,
{ {
unsigned width = image.width(); unsigned width = image.width();
unsigned height = image.height(); 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); // structure for color quantization
} hextree<mapnik::rgba> tree(opts.colors);
if (opts.gamma > 0) if (opts.trans_mode >= 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.setTransMode(opts.trans_mode);
tree.insert(mapnik::rgba(U2RED(val), U2GREEN(val), U2BLUE(val), U2ALPHA(val))); }
if (opts.gamma > 0)
{
tree.setGamma(opts.gamma);
} }
}
//transparency values per palette index for (unsigned y = 0; y < height; ++y)
std::vector<mapnik::rgba> pal; {
tree.create_palette(pal); typename T2::pixel_type const * row = image.getRow(y);
std::vector<mapnik::rgb> palette; for (unsigned x = 0; x < width; ++x)
std::vector<unsigned> alphaTable; {
for (unsigned i=0; i<pal.size(); ++i) 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
{ {
palette.push_back(rgb(pal[i].r, pal[i].g, pal[i].b)); throw std::runtime_error("Can't quantize images with less than 3 pixels");
alphaTable.push_back(pal[i].a);
} }
save_as_png8<T1, T2, hextree<mapnik::rgba> >(file, image, tree, palette, alphaTable, opts);
} }
template <typename T1, typename T2> template <typename T1, typename T2>