Fig. 1. Block diagram. (a) Markov process; (b) hidden Markov process

Fig. 2. Smoke in the feeding and stirring process. (a) Smoke in feeding stage; (b) smoke in stirring stage

Fig. 3. Smoke in the smooth melting process. (a) Smoke 1; (b) smoke 2

Fig. 4. Smoke in the last stage of smelting process. (a) Smoke 1; (b) smoke 2

Fig. 5. Smoke in the component analysis and release stage. (a) Smoke in analysis stage; (b) smoke in release stage

Fig. 6. Sequential image sampling

Fig. 7. HMM training process

Fig. 8. Flow of smoke image classification prediction using HMM

Fig. 9. Recognition accuracy comparison for different HMM states