How to calculate area under peak?

I have many multiple peak events/signals as shown in attached picture. I want to calculate area under each individual peaks (in green color). For all signals I have baseline current (in red color), current with respect to time points and start and end time point of peak.

[Nakul]

You can integrate the signal and do necessary modification to get the area.

Answer 1

[KSSV]

You can calculate area using either by trapz or polyarea. Read about them.