1. A method for performing multi-projection comprising: executing by a projection processor module computer program code stored on a non-transitory storage medium, the computer program code comprising: program code that estimates the intensity transfer function (ITF) of a plurality of projectors; program code that calculates an optimal black offset threshold for each of the projectors by using each of the ITFs; and program code that applies the optimal black offset threshold to an image projection by each of the projectors, wherein the processor module executes the computer program code stored on the non-transitory storage medium in accordance with Equations 1 and 2 below, I ⁢ ⁢ T ⁢ ⁢ F black ⁡ ( S ) = a * S 2 + b * S + base_offset , 0 ≤ S ≤ 255 [ Equation ⁢ ⁢ 1 ] th i = ⁢ argmin th ⁡ ( 0 ≤ th ≤ 25 ) [ ( avg_Sat BL i - I ⁢ ⁢ T ⁢ ⁢ F i ⁡ ( th ) ) + ⁢ ( avgSat BR i - I ⁢ ⁢ T ⁢ ⁢ F i ⁡ ( th ) ) ) ] = ⁢ argmin th ⁡ ( 0 ≤ th ≤ 25 ) ⁡ [ avg_Sat BL i + avgSat BR i - 2 * I ⁢ ⁢ T ⁢ ⁢ F i ⁡ ( th ) ] [ Equation ⁢ ⁢ 2 ] wherein in Equation 1, S is a range of values between 0 and 255, ‘a’ and ‘b’ are approximate values represented by a=0.028 and b=-0.3142, and the base offset value base offset is obtained by projecting a pure black image on a screen by all projectors at the same time, capturing the pure black image by a still camera, calculating the average intensity value of all overlapping regions and non-overlapping region for each projector using the captured image, with the calculated average intensity value corresponding to the base offset value, and wherein Equation 2 represents the optimal value to which the image of the non-overlapping region is converted to make a seamless display by estimating the black offset value of the left and right overlapped region to provide the threshold value of the intensity, T represents the number of the projector, ‘BL’ represents the left overlapped region at the i th projector and ‘BR’ represents the right overlapped region at the i th projector.