FID Calculation
What is FID?
FID measures how close fake (generated) images are to real images. Low FID = good GAN. High FID = bad GAN.
Reading Variance
RULE: exponent has -x²/(2k) → variance = k
-x²/2 → variance=1, σ=1
-x²/8 → variance=4, σ=2
-y²/18 → variance=9, σ=3
FID Formula
Part 1 = (mean_P_x - mean_Q_x)² + (mean_P_y - mean_Q_y)² Part 2 = (σ_P_x - σ_Q_x)² + (σ_P_y - σ_Q_y)² FID = Part 1 + Part 2