Fig. 1. Flow chart of proposed algorithm

Fig. 2. Comparison of reflection images constrained by different TV models. (a) Original drawing; (b) original TV model; (c) proposed TV(r=3); (d) proposed TV (r=0.3)

Fig. 3. Comparison of illumination correction images.(a) Original drawing; (b) μ=0.5; (c) adaptive μ value

Fig. 4. Comparison of Retinex decomposition. (a) Original images; (b) model of reference [15]; (c) STAR; (d) WVM; (e) SSR; (f) proposed model

Fig. 5. Contrast of enhanced images. (a) Original images; (b) algorithm of reference [11]; (c) algorithm of reference [15]; (d) STAR; (e) WVM; (f) MSRCR; (g) algorithm of reference [13]; (h) proposed algorithm

Fig. 6. Comparison of safety helmet and human body detection between low illumination image and enhanced image. (a) Original image detection and recognition results; (b) enhanced image detection and recognition results