Image_uc GetProposedImage(const Image_uc& im, unsigned int iteration, Image_uc& blur) {
// Set up the RNGs
static boost::mt19937 rng;
static boost::uniform_int<> uniform255(0, 255);
static boost::uniform_int<> uniform3sigma(-1.5*sigma, 1.5*sigma);
static boost::variate_generator<boost::mt19937&, boost::uniform_int<> > noise255(rng, uniform255);
static boost::variate_generator<boost::mt19937&, boost::uniform_int<> > noise3sigma(rng, uniform3sigma);
Image_uc proposed(im.Height(), im.Width());
if (iteration % 2 == 0) {
// On even iterations, proposal is a gaussian-blurred version of the
// current image, plus a small amount of gaussian noise
blur = ApplyGaussBlur(im, kernelRadius, gaussianKernel);
for (int i = 0; i < im.Height(); ++i) {
for (int j = 0; j < im.Width(); ++j) {
int p = (int)blur(i, j) + (int)noise3sigma();
if (p > 255) p = 255;
if (p < 0) p = 0;
proposed(i, j) = (unsigned char)p;
}
}
} else {
// On odd iterations, proposal is a uniform random image
for (int i = 0; i < im.Height(); ++i) {
for (int j = 0; j < im.Width(); ++j) {
proposed(i, j) = (unsigned char)(noise255());
}
}
}
return proposed;
}
void CSteganoExecutor::onProposed(PArgsList pArgsList)
{
emit proposed(pArgsList);
}
