Algorithm 1: Left-right lung boxes detection
Input: A CT scan of the COVID-19 patient which consists of hundreds of CT images, m is the number of images
Output: coordinate value of the biggest left–right lung boxes
1: for i do m
2:  lung segmentation = lungmodel(image[i])
3:  calculate the number of connection regions. ← lung segmentation
4:  if the number ofregions 2: 2 then
5:   (Xu , Yu, XL2′ Yu), (XR 1, YR1, XR2′ YR2). ← the two biggest regions
6:  if the number ofregions is 1 then
7:   (Xu, Yu,XL2′ Yu), (XR1, YR1, XR 2, YR2). ← median of the one region
8:  end if
9:  save (Xu , Yu, XL 2, Yu), (XR 1, YR1, XR2′ YR2)
10: end for
11: ({Xu } min' {Yu}min' {Xu } max' {Yu}max), ({XRI } min' {YRI } min' {XR2 } max' {YR2} max)