• Laser & Optoelectronics Progress
  • Vol. 57, Issue 10, 101008 (2020)
Fu Liu, Maojun Li*, Jianwen Hu, Yuhe Xiao, and Zhan Qi
Author Affiliations
  • School of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China
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    DOI: 10.3788/LOP57.101008 Cite this Article Set citation alerts
    Fu Liu, Maojun Li, Jianwen Hu, Yuhe Xiao, Zhan Qi. Expression Recognition Based on Low Pixel Face Images[J]. Laser & Optoelectronics Progress, 2020, 57(10): 101008 Copy Citation Text show less
    Pipeline of the facial expression preprocessing
    Fig. 1. Pipeline of the facial expression preprocessing
    CNN model
    Fig. 2. CNN model
    8 kinds of facial expression images
    Fig. 3. 8 kinds of facial expression images
    Diagram of SoftMax average voting
    Fig. 4. Diagram of SoftMax average voting
    LayerTypeKernel size /pixel×pixelStrideOutput numberOutput size /pixel×pixel
    Layer 1Convolution3×316430×30
    Layer 2Convolution3×3112828×28
    Layer 3Max pooling2×2212814×14
    Layer 4Convolution3×3112814×14
    Layer 5Convolution3×3112814×14
    Layer 6Convolution3×3125612×12
    Layer 7Max pooling2×222566×6
    Layer 8Convolution3×312566×6
    Layer 9Convolution3×312566×6
    Layer 10Average pooling3×332562×2
    Layer 11Convolution2×215121×1
    Layer 12Fully connected---160×1
    OutputSoftMax---8×1
    Table 1. Convolutional network parameters
    CategoryAngryDisgustFearfulHappySadSurprisedScornNeutral
    Train database14040122207800143008970858054608970
    Test database2724152815161215
    Table 2. Facial expression dataset
    ModelOriginaldatabaseLocal binarypatterndatabaseHistogramequalizationdatabase
    Accuracy /%89.586.990.5
    Time/s1.541.271.56
    Table 3. Comparison of recognition accuracy and time
    Category AccuracyAngryDisgustFearfulHappySadSurprisedScornNeutralTotal
    First experiment96.391.760.0100.086.7100.083.393.390.5
    Second experiment88.991.786.7100.080.0100.083.393.391.2
    Third experiment96.395.860.0100.086.793.875.093.389.8
    Total93.893.168.9100.084.597.980.593.390.5
    Table 4. Improved recognition accuracy of CNN modelunit: %
    ModelLeNet-5Without decision level
    Accuracy /%74.687.9
    Time /s0.590.31
    Table 5. Comparison of recognition accuracy and time between two models
    Fu Liu, Maojun Li, Jianwen Hu, Yuhe Xiao, Zhan Qi. Expression Recognition Based on Low Pixel Face Images[J]. Laser & Optoelectronics Progress, 2020, 57(10): 101008
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