Fig. 1. Results comparison. (a) Operation results by PST; (b) Operation results by Eq. (13)

Fig. 2. Error curve of the calculation result in Fig.1

Fig. 3. Grayscale variance and angle map variance maps of the source images. (a)(d) Blurred and clear source images;(b)(e) grayscale variance of Fig. (a) and (d); (c)(f) angle map variance of Fig. (a) and (d)

Fig. 4. Original image and high-frequency information extraction results. (a)(b) Original images; (c)(d) high-frequency information extracted by kernel function in Ref. [9] and proposed kernel function

Fig. 5. Flow chart of proposed multi-focus image fusion algorithm

Fig. 6. Fusion results of Lytro-07. (a) Fusion result by DWT; (b) fusion result by Laplace operator; (c) fusion result by SR; (d) fusion result by guided filter; (e) fusion result by JCAN; (f) fusion result using the kernel function in Ref. [9]; (g) fusion result using the proposed kernel function

Fig. 7. Difference maps of fusion results. (a)-(g) Corresponding to the difference maps in Fig. 6 (a)--(g)

Fig. 8. Local enlarged drawing. (a)(b) Corresponding to the local enlarged drawing in Fig. 7 (f) and (g)

Fig. 9. Source images and fusion results of proposed algorithm. (a)(b) Source images; (c) fusion results