Figure 5From: Application of the topological derivative to post-processing infrared time-harmonic thermograms for defect detectionThermograms with \(\omega =0.8\mbox{ Hz}\). Left: amplitude of the temperature \(|\mathcal{T}^{\mathrm{front}}|\). Right: difference between thermograms corresponding to a healthy plate and a faulty one. At low frequencies defect detection is impossible at plain sightBack to article page