/**
* Compute a linear blend of the pixel colors in two provided images according
* to a parameter t.
*/
STImage *BlendImages(STImage *image1, STImage *image2, float t)
{
int width = image1->GetWidth();
int height = image1->GetHeight();
STImage *result = new STImage(width, height, STColor4ub(255,255,255,255));
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
STColor4f pixel1 = STColor4f(image1->GetPixel(x, y));
STColor4f pixel2 = STColor4f(image2->GetPixel(x, y));
STColor4f newPixel = pixel1*(1-t) + pixel2*t;
result->SetPixel(x, y, STColor4ub(newPixel));
}
}
return result;
}
STImage *FieldMorph(STImage *image,
const std::vector<Feature> &sourceFeatures,
const std::vector<Feature> &targetFeatures,
float t, float a, float b, float p)
{
int width = image->GetWidth();
int height = image->GetHeight();
STImage *result = new STImage(width, height, STColor4ub(255,255,255,255));
std::vector<Feature> interpolatedFeatures = interpolateFeatures(sourceFeatures, targetFeatures, t);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
STVector2 dispSum = STVector2(0, 0);
float weightsum = 0;
STPoint2 X = STPoint2(x, y);
int numFeatures = sourceFeatures.size();
for (int i = 0; i < numFeatures; i++) {
STPoint2 Pp = sourceFeatures[i].P;
STPoint2 Qp = sourceFeatures[i].Q;
STPoint2 P = interpolatedFeatures[i].P;
STPoint2 Q = interpolatedFeatures[i].Q;
float u = calculateU(X, P, Q);
float v = calculateV(X, P, Q);
STPoint2 Xp = calculateXp(Pp, Qp, u, v);
STVector2 displacement = STVector2(Xp) - STVector2(X);
float dist = calculateDistance(X, P, Q, u, v);
float weight = calculateWeight(Q, P, a, b, p, dist);
dispSum += displacement * weight;
weightsum += weight;
}
STPoint2 Xprime = X + dispSum/weightsum;
result->SetPixel(x, y, interpolatedColor(Xprime, image));
}
}
return result;
}