Entropy and Contrast Enhancement of Infrared Thermal Images Using the Multiscale Top-Hat Transform

. 2019 Mar 4;21(3):244. doi: 10.3390/e21030244

Algorithm 1 Proposed method for TII Enhancement

Input:I, G,

G^{'}

, n,

ω

Output:

I_{E}

(Enhanced image)
Initialization: G,

G^{'}

1: for

i = 1

to n do
2: Calculation of top-hat transform.

M B_{i} = I - ((I ⊖ G_{i}) \oplus G_{i}^{'})

(Equation (11))

M D_{i} = ((I \oplus G_{i}) ⊖ G_{i}^{'}) - I

(Equation (12))
3: Calculation of subtractions from neighboring scales, obtained through the top-hat transform. The top-hat is subtracted with the previous difference, from the first subtraction of the first neighboring top-hat.

S N B S_{i - 1} = \{\begin{matrix} M B_{i} - M B_{i - 1}, to i = 2 \\ M B_{i} - S N B S_{i - 2}, to i > 2 \end{matrix} (Equation (13))

S N D S_{i - 1} = \{\begin{matrix} M D_{i} - M D_{i - 1}, to i = 2 \\ M D_{i} - S N D S_{i - 2}, to i > 2 \end{matrix} (Equation (14))

4: end for
5: Calculation of the maximum values of all the multiple scales obtained.

S M B = \sum_{i = 1}^{n} M B_{i}

(Equation (15))

S M D = \sum_{i = 1}^{n} M D_{i}

(Equation (16))

S S N B S = \sum_{i = 1}^{n - 1} S N B S_{i - 1}

(Equation (17))

S S N D S = \sum_{i = 1}^{n - 1} S N D S_{i - 1}

(Equation (18))
6: TII enhancement calculation.The contrast enhancement calculation consists of adding the results of the multiple bright scales to the original image and subtracting the results of the multiple dark scales.

I_{E} = I + ω \times (S M B + S S N B S) - ω \times (S N D + S S N D S)

(Equation (19))
7: return

I_{E}