dlib C++ Library - webp_loader.h

// Copyright (C) 2022 Davis E. King (davis@dlib.net), Martin Sandsmark, Adrià Arrufat
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_WEBP_IMPORT
#define DLIB_WEBP_IMPORT
#include <vector>
#include "webp_loader_abstract.h"
#include "image_loader.h"
#include "../pixel.h"
#include "../dir_nav.h"
#include "../test_for_odr_violations.h"
namespace dlib
{
 class webp_loader : noncopyable
 {
 public:
 webp_loader(const char* filename);
 webp_loader(const std::string& filename);
 webp_loader(const dlib::file& f);
 webp_loader(const unsigned char* imgbuffer, size_t buffersize);
 long nr() const;
 long nc() const;
 template<typename image_type>
 void get_image(image_type& image) const
 {
#ifndef DLIB_WEBP_SUPPORT
 /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 You are getting this error because you are trying to use the webp_loader
 object but you haven't defined DLIB_WEBP_SUPPORT. You must do so to use
 this object. You must also make sure you set your build environment
 to link against the libwebp library.
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*/
 static_assert(sizeof(image_type) == 0, "webp support not enabled.");
#endif
 image_view<image_type> vimg(image);
 vimg.set_size(height_, width_);
 typedef typename image_traits<image_type>::pixel_type pixel_type;
 unsigned char* output = reinterpret_cast<unsigned char*>(image_data(vimg));
 const int stride = width_step(vimg);
 const size_t output_size = stride * height_;
 if (pixel_traits<pixel_type>::rgb_alpha)
 {
 if (pixel_traits<pixel_type>::bgr_layout)
 read_bgra(output, output_size, stride);
 else
 read_rgba(output, output_size, stride);
 return;
 }
 if (pixel_traits<pixel_type>::rgb)
 {
 if (pixel_traits<pixel_type>::bgr_layout)
 read_bgr(output, output_size, stride);
 else
 read_rgb(output, output_size, stride);
 return;
 }
 // If we end up here, we are out of our fast path, and have to do it manually
 array2d<rgb_alpha_pixel> decoded;
 decoded.set_size(height_, width_);
 unsigned char* output_dec = reinterpret_cast<unsigned char*>(image_data(decoded));
 const int stride_dec = width_step(decoded);
 const size_t output_dec_size = stride_dec * height_;
 read_rgba(output_dec, output_dec_size, stride_dec);
 for (int r = 0; r < height_; r++)
 {
 for (int c = 0; c < width_; c++)
 {
 assign_pixel(vimg[r][c], decoded[r][c]);
 }
 }
 }
 private:
 void get_info();
 void read_bgra(unsigned char *out, const size_t out_size, const int out_stride) const;
 void read_bgr(unsigned char *out, const size_t out_size, const int out_stride) const;
 void read_rgba(unsigned char *out, const size_t out_size, const int out_stride) const;
 void read_rgb(unsigned char *out, const size_t out_size, const int out_stride) const;
 void read_argb(unsigned char *out, const size_t out_size, const int out_stride) const;
 int height_;
 int width_;
 std::vector<unsigned char> data_;
 };
// ----------------------------------------------------------------------------------------
 template <
 typename image_type
 >
 void load_webp (
 image_type& image,
 const std::string& file_name
 )
 {
 webp_loader(file_name).get_image(image);
 }
 template <
 typename image_type
 >
 void load_webp (
 image_type& image,
 const unsigned char* imgbuff,
 size_t imgbuffsize
 )
 {
 webp_loader(imgbuff, imgbuffsize).get_image(image);
 }
 template <
 typename image_type
 >
 void load_webp (
 image_type& image,
 const char* imgbuff,
 size_t imgbuffsize
 )
 {
 webp_loader(reinterpret_cast<const unsigned char*>(imgbuff), imgbuffsize).get_image(image);
 }
// ----------------------------------------------------------------------------------------
}
#ifdef NO_MAKEFILE
#include "webp_loader.cpp"
#endif
#endif // DLIB_WEBP_IMPORT