void OpenCVPicture::colorDistortion(RNG &rng, int sigma1, int sigma2,
int sigma3, int sigma4) {
// Call as a final preprocessing step, after any affine transforms and
// jiggling.
assert(mat.type() % 8 == 5); // float
std::vector<float> delta1(mat.channels());
std::vector<float> delta2(mat.channels());
std::vector<float> delta3(mat.channels());
std::vector<float> delta4(mat.channels());
for (int j = 0; j < mat.channels(); j++) {
delta1[j] = rng.normal(0, sigma1);
delta2[j] = rng.normal(0, sigma2);
delta3[j] = rng.normal(0, sigma3);
delta4[j] = rng.normal(0, sigma4);
}
float *matData = ((float *)(mat.data));
for (int y = 0; y < mat.rows; y++) {
for (int x = 0; x < mat.cols; x++) {
int j = x * mat.channels() + y * mat.channels() * mat.cols;
bool interestingPixel = false;
for (int i = 0; i < mat.channels(); i++)
if (std::abs(matData[i + j] - backgroundColor) > 2)
interestingPixel = true;
if (interestingPixel) {
for (int i = 0; i < mat.channels(); i++)
matData[i + j] +=
delta1[i] + delta2[i] * (matData[i + j] - backgroundColor) +
delta3[i] * (x - mat.cols / 2) + delta4[i] * (y - mat.rows / 2);
}
}
}
}
void distortImageColor(cv::Mat& mat, RNG& rng, float sigma1, float sigma2, float sigma3, float sigma4) {
std::vector<float> delta1(mat.channels());
std::vector<float> delta2(mat.channels());
std::vector<float> delta3(mat.channels());
std::vector<float> delta4(mat.channels());
for (int j=0;j<mat.channels();j++) {
delta1[j]=rng.normal(0,sigma1);
delta2[j]=rng.normal(0,sigma2);
delta3[j]=rng.normal(0,sigma3);
delta4[j]=rng.normal(0,sigma4);
}
int j=0;
for (int y=0;y<mat.rows;++y) {
for (int x=0;x<mat.cols;++x) {
for (int i=0;i<mat.channels();++i) {
mat.ptr()[j]=std::max(0,std::min(255,
(int)(mat.ptr()[j]+
delta1[i]+
delta2[i]*cos(mat.ptr()[j]*3.1415926535/255)+
delta3[i]*(x-mat.cols/2)+
delta4[i]*(y-mat.rows/2))));
++j;
}
}
}
}