// Copyright (C) 2011 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_SAVE_PnG_Hh_
#define DLIB_SAVE_PnG_Hh_
#include <vector>
#include <string>
#include <fstream>
#include <functional>
#include "save_png_abstract.h"
#include "image_saver.h"
#include "../array2d.h"
#include "../pixel.h"
#include "../matrix/matrix_exp.h"
#include "../image_transforms/assign_image.h"
namespace dlib
{
// ----------------------------------------------------------------------------------------
namespace impl
{
enum png_type
{
png_type_rgb,
png_type_rgb_alpha,
png_type_gray,
};
void impl_save_png (
std::function<void(const char*, std::size_t)> clb,
std::vector<unsigned char*>& row_pointers,
const long width,
const png_type type,
const int bit_depth,
const bool swap_rgb = false
);
// ----------------------------------------------------------------------------------------
template <
class image_type
>
void save_png(
const image_type& img_,
std::function<void(const char*, std::size_t)> clb
)
{
const_image_view<image_type> img(img_);
// make sure requires clause is not broken
DLIB_CASSERT(img.size() != 0,
"\t save_png()"
<< "\n\t You can't save an empty image as a PNG"
);
#ifndef DLIB_PNG_SUPPORT
/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
You are getting this error because you are trying to use save_png()
but you haven't defined DLIB_PNG_SUPPORT. You must do so to use
this function. You must also make sure you set your build environment
to link against the libpng library.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*/
COMPILE_TIME_ASSERT(sizeof(image_type) == 0);
#else
std::vector<unsigned char*> row_pointers(img.nr());
using pixel_type = pixel_type_t<image_type>;
if (std::is_same<rgb_pixel,pixel_type>::value)
{
for (unsigned long i = 0; i < row_pointers.size(); ++i)
row_pointers[i] = (unsigned char*)(&img[i][0]);
impl::impl_save_png(std::move(clb), row_pointers, img.nc(), impl::png_type_rgb, 8);
}
else if (std::is_same<bgr_pixel,pixel_type>::value)
{
for (unsigned long i = 0; i < row_pointers.size(); ++i)
row_pointers[i] = (unsigned char*)(&img[i][0]);
impl::impl_save_png(std::move(clb), row_pointers, img.nc(), impl::png_type_rgb, 8, true);
}
else if (std::is_same<rgb_alpha_pixel,pixel_type>::value)
{
for (unsigned long i = 0; i < row_pointers.size(); ++i)
row_pointers[i] = (unsigned char*)(&img[i][0]);
impl::impl_save_png(std::move(clb), row_pointers, img.nc(), impl::png_type_rgb_alpha, 8);
}
else if (pixel_traits<pixel_type>::lab || pixel_traits<pixel_type>::hsi || pixel_traits<pixel_type>::rgb)
{
// convert from Lab or HSI to RGB (Or potentially RGB pixels that aren't laid out as R G B)
array2d<rgb_pixel> temp_img;
assign_image(temp_img, img_);
for (unsigned long i = 0; i < row_pointers.size(); ++i)
row_pointers[i] = (unsigned char*)(&temp_img[i][0]);
impl::impl_save_png(std::move(clb), row_pointers, img.nc(), impl::png_type_rgb, 8);
}
else if (pixel_traits<pixel_type>::rgb_alpha)
{
// convert from RGBA pixels that aren't laid out as R G B A
array2d<rgb_alpha_pixel> temp_img;
assign_image(temp_img, img_);
for (unsigned long i = 0; i < row_pointers.size(); ++i)
row_pointers[i] = (unsigned char*)(&temp_img[i][0]);
impl::impl_save_png(std::move(clb), row_pointers, img.nc(), impl::png_type_rgb_alpha, 8);
}
else // this is supposed to be grayscale
{
DLIB_CASSERT(pixel_traits<pixel_type>::grayscale, "impossible condition detected");
if (pixel_traits<pixel_type>::is_unsigned && sizeof(pixel_type) == 1)
{
for (unsigned long i = 0; i < row_pointers.size(); ++i)
row_pointers[i] = (unsigned char*)(&img[i][0]);
impl::impl_save_png(std::move(clb), row_pointers, img.nc(), impl::png_type_gray, 8);
}
else if (pixel_traits<pixel_type>::is_unsigned && sizeof(pixel_type) == 2)
{
for (unsigned long i = 0; i < row_pointers.size(); ++i)
row_pointers[i] = (unsigned char*)(&img[i][0]);
impl::impl_save_png(std::move(clb), row_pointers, img.nc(), impl::png_type_gray, 16);
}
else
{
// convert from whatever this is to 16bit grayscale
array2d<dlib::uint16> temp_img;
assign_image(temp_img, img_);
for (unsigned long i = 0; i < row_pointers.size(); ++i)
row_pointers[i] = (unsigned char*)(&temp_img[i][0]);
impl::impl_save_png(std::move(clb), row_pointers, img.nc(), impl::png_type_gray, 16);
}
}
#endif
}
}
// ----------------------------------------------------------------------------------------
template <
class image_type
>
void save_png (
const image_type& img,
std::ostream& out
)
{
impl::save_png (
img,
[&out](const char* data, std::size_t ndata) {
out.write(data, ndata);
}
);
}
// ----------------------------------------------------------------------------------------
template <
class image_type
>
void save_png (
const image_type& img,
const std::string& file_name
)
{
std::ofstream out(file_name, std::ios::binary);
save_png(img, out);
}
// ----------------------------------------------------------------------------------------
template <
class image_type,
class Byte,
class Alloc
>
void save_png (
const image_type& img,
std::vector<Byte, Alloc>& buf
)
{
static_assert(is_byte<Byte>::value, "Byte must be char, int8_t or uint8_t");
impl::save_png (
img,
[&buf](const char* data, std::size_t ndata) {
buf.insert(end(buf), data, data + ndata);
}
);
}
// ----------------------------------------------------------------------------------------
template <
class T, long NR, long NC, class MM, class L,
class Output
>
void save_png (
const matrix<T,NR,NC,MM,L>& img,
Output&& out
)
{
save_png(make_image_view(img), std::forward<Output>(out));
}
// ----------------------------------------------------------------------------------------
template <
class EXP,
class Output
>
void save_png (
const matrix_exp<EXP>& img,
Output&& out
)
{
array2d<typename EXP::type> temp;
assign_image(temp, img);
save_png(temp, std::forward<Output>(out));
}
// ----------------------------------------------------------------------------------------
}
#ifdef NO_MAKEFILE
#include "save_png.cpp"
#endif
#endif // DLIB_SAVE_PnG_Hh_