/*! \brief Helper function to write out a collection of pixels as
a bmp file.
*/
inline void writeBMPFile(const std::string& filename,
const std::vector<uint8_t>& image,
size_t width, size_t height,
size_t components = 4)
{
std::ofstream bmpFile(filename.c_str(), std::fstream::binary);
bmpFile << detail::bitmap_information_header(width, height);
if (components < 3)
M_throw() << "Cannot write out bitmaps with less than three components";
size_t rowpadding = ((width * 3 + 3) & 0xFFFC) - width * 3;
for (size_t y(0); y < height; ++y)
{
for (size_t x(0); x < width; ++x)
{
detail::write(bmpFile, image[components * (y * width + x) + 0]);
detail::write(bmpFile, image[components * (y * width + x) + 1]);
detail::write(bmpFile, image[components * (y * width + x) + 2]);
}
for (size_t xpad(0); xpad < rowpadding; ++xpad)
detail::write(bmpFile, int8_t(0));
}
}
inline void rfft(const DEVector<float>::Type &x,
CDEVector<float>::Type &X, int fftsize)
{
// zero pad to fftsize
DEVector<float>::Type xpad(fftsize);
std::fill_n(xpad.data(), fftsize, 0);
xpad(_(1,x.length())) = x;
// calc FFTs
fftwf_plan p1;
X.resize(fftsize/2+1);
p1 = fftwf_plan_dft_r2c_1d(fftsize, &xpad(1),
reinterpret_cast<fftwf_complex*>( &X(1) ),
FFTW_ESTIMATE);
fftwf_execute(p1);
fftwf_destroy_plan(p1);
}
