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To solve nonlinear problem of camera lens distortion, this paper proposed an improved adaptive chaotic variation PSO algorithm. In IACPSO algorithm, particle swarm optimized with two independent particle swarm working together. The first particle swarm adopted fixed weights with cubic mapping chaos factor to disturb the stagnant particle during the evolution, while the second particle swarm used adaptive inertia weight to adjust the inertia weight dynamically according to fitness value. The two particle swarms' optimal particles decided the global optimal solution during the iteration. In order to verify IACPSO algorithm' s correction performance on lens distortion, this paper compared with a variety of particle swarm optimization algorithms. The simulation results show that IACPSO algorithm has strong robustness in solving process. In low level situation, IACPSO algorithm is the best for correcting the lens distortion. At last, two groups of instances test the effectiveness of proposed method. [ABSTRACT FROM AUTHOR]

Coronary artery fractional flow reserve (FFR) is a critical physiological indicator for assessment of impaired blood flow caused by coronary artery stenosis. The wire-based invasive measurement of blood flow pressure gradient across stenosis is the gold standard for clinical measurement of FFR. However, it has the risk of vascular injury and requires the use of vasodilators, increasing the time and overall cost of interventional examination. Coronary imaging is playing an important role in clinical diagnosis of stenotic lesions, evaluation of severity of lesions, and planning of therapies. In recent years, the computation of FFR based on the physiological information of blood flow obtained from routinely collected coronary image data has become a research focus in this field. This technique reduces the cost of physiological assessment of coronary lesions and the use of pressure wires. It is beneficial to strengthen the physiological guidance in interventional therapy. In order to better understand this emerging technique, this paper highlights its implementation principle and diagnostic performance, analyzes practical problems and current challenges in clinical applications, and discusses possible future development.