A method for processing an image based on an inter prediction, the method comprising: obtaining at least one motion information of at least one corresponding block located in a current picture; deriving reverse motion information of a current block by using the at least one motion information of the at least one corresponding block; adding the reverse motion information as a motion information candidate, to a motion information candidate list of the current block including a plurality of motion information candidates; deriving motion information of the current block from the motion information selected among the plurality of motion information candidates within the motion information candidate list; and generating a prediction block of the current block by using the motion information of the current block, wherein the obtaining at least one motion information of at least one corresponding block comprises: searching for one or more blocks having motion information within at least one reference picture of the current picture; scaling the motion information of the one or more blocks within the at least one reference picture to be directed to the current picture to obtain first motion information; applying an opposite sign to the first motion information to obtain second motion information when the first motion information specifies an area of the current picture; and storing the second motion information in a corresponding block corresponding to the area of the current picture, the corresponding block being located in the current picture, and wherein the deriving reverse motion information of a current block comprises: determining the second motion information stored in the corresponding block which overlaps with the current block as the reverse motion information of the current block. obtaining at least one motion information of at least one corresponding block located in a current picture; deriving reverse motion information of a current block by using the at least one motion information of the at least one corresponding block; adding the reverse motion information as a motion information candidate, to a motion information candidate list of the current block including a plurality of motion information candidates; deriving motion information of the current block from the motion information selected among the plurality of motion information candidates within the motion information candidate list; and generating a prediction block of the current block by using the motion information of the current block, wherein the obtaining at least one motion information of at least one corresponding block comprises: searching for one or more blocks having motion information within at least one reference picture of the current picture; scaling the motion information of the one or more blocks within the at least one reference picture to be directed to the current picture to obtain first motion information; applying an opposite sign to the first motion information to obtain second motion information when the first motion information specifies an area of the current picture; and storing the second motion information in a corresponding block corresponding to the area of the current picture, the corresponding block being located in the current picture, and wherein the deriving reverse motion information of a current block comprises: determining the second motion information stored in the corresponding block which overlaps with the current block as the reverse motion information of the current block. searching for one or more blocks having motion information within at least one reference picture of the current picture; scaling the motion information of the one or more blocks within the at least one reference picture to be directed to the current picture to obtain first motion information; applying an opposite sign to the first motion information to obtain second motion information when the first motion information specifies an area of the current picture; and storing the second motion information in a corresponding block corresponding to the area of the current picture, the corresponding block being located in the current picture, and wherein the deriving reverse motion information of a current block comprises: determining the second motion information stored in the corresponding block which overlaps with the current block as the reverse motion information of the current block.