void write_png(const string& filename, const image3f& img, bool flipY) {
vector<unsigned char> img_png(img.width()*img.height()*4);
for(int x = 0; x < img.width(); x++ ) {
for( int y = 0; y < img.height(); y++ ) {
int i_img = y * img.width() + x;
int i_png = ( ( flipY ? (img.height()-1-y) : y ) * img.width() + x ) * 4;
img_png[i_png+0] = (unsigned char)clamp(img.data()[i_img].x * 255, 0.0f, 255.0f);
img_png[i_png+1] = (unsigned char)clamp(img.data()[i_img].y * 255, 0.0f, 255.0f);
img_png[i_png+2] = (unsigned char)clamp(img.data()[i_img].z * 255, 0.0f, 255.0f);
img_png[i_png+3] = 255;
}
}
unsigned error = lodepng::encode(filename, img_png, img.width(), img.height());
error_if_not(not error, "cannot write png image: %s", filename.c_str());
}
void transfer(image3f& img) {
auto w = img.width();
auto h = img.height();
for(int j = 0; j < h; j ++) {
for(int i = 0; i < w; i ++) {
img.at(i,h-1-j) = trace_image_buffer.accum.at(i,h-1-j) / trace_image_buffer.samples.at(i,h-1-j);
}
}
}
void write_pfm(const string& filename, const image3f& img, bool flipY) {
_write_pnm(filename.c_str(), 'f', img.width(), img.height(), 3, false,
(flipY)?(unsigned char*)img.flipy().data():(unsigned char*)img.data());
}