A method for generating feature maps by using a device adopting CNN including feature up-sampling networks, wherein the device includes (i) a down-sampling block for reducing a size of an input image; (ii) each of a -th to a (1-k)-th filter blocks (410_1,...410_k) from which each of a -th to a (1-k)-th feature maps is acquired by performing one or more convolution operations; and (iii) a (2-k)-th to a -th up-sampling blocks each of which correspondingly interacts with each of the -th to the (1-k)-th filter blocks (410_1,...410_k), comprising steps of: (a) the device, if the input image is obtained, causing the down-sampling block to acquire a down-sampling image by applying a predetermined operation to the input image; (b) the device, if the down-sampling image is obtained, causing each of the -th to the (1-k)-th filter blocks (410_1,...410_k) to sequentially acquire each of the -th to the (1-k)-th feature maps by applying the one or more convolution operations to the down-sampling image; and (c) the device causing the -th up-sampling block to (i) receive the down-sampling image from the down-sampling block, and (ii) receive the -th feature map from the -th up-sampling block, and then rescale a size of the -th feature map to be identical to that of the down-sampling image and (iii) apply a summing-up operation to the down-sampling image and the -th rescaled feature map, thereby acquiring the -th feature map and causing, if M is an integer greater than or equal to one, the (2-(M+1))-th up-sampling block to (i) receive the (1-M)-th feature map from the (1-M)-th filter block, and (ii) receive the (2-(M+2))-th feature map from the (2-(M+2))-th up-sampling block, and then rescale a size of the (2-(M+2))-th feature map to be identical to that of the (1-M)-th feature map and (iii) apply a summing-up operation to the (1-M)-th feature map and the (2-(M+2))-th rescaled feature map in order to generate the (2-(M+1))-th feature map, thereby acquiring the (2-k)-th to the -th feature maps, wherein the device, at the step of (c), in case M is an integer greater than or equal to 1 and less than or equal to (k-2), causing the (2-(M+1))-th up-sampling block to perform processes of (i) obtaining an (1-M)-th adjusted feature map whose number of channels is modified by a first filter in the (2-(M+1))-th up-sampling block applying a convolution operation to the (1-M)-th feature map; (ii) obtaining an (2-(M+2))-th adjusted feature map whose number of channels is modified by a second filter in the (2-(M+1))-th up-sampling block applying a convolution operation to the (2-(M+2))-th feature map; and then obtaining the (2-(M+2))-th rescaled feature map by applying an up-sampling operation to the (2-(M+2))-th adjusted feature map; (iii) computing the (1-M)-th adjusted feature map with the (2-(M+2))-th rescaled feature map in order to produce the (2-(M+1))-th feature map; and (iv) relaying to the (2-M)-th up-sampling block the (2-(M+1))-th feature map acquired from the (2-(M+1))-th up-sampling block, thereby acquiring the (2-(k-1))-th to the -th feature maps. (a) the device, if the input image is obtained, causing the down-sampling block to acquire a down-sampling image by applying a predetermined operation to the input image; (b) the device, if the down-sampling image is obtained, causing each of the -th to the (1-k)-th filter blocks (410_1,...410_k) to sequentially acquire each of the -th to the (1-k)-th feature maps by applying the one or more convolution operations to the down-sampling image; and (c) the device causing the -th up-sampling block to (i) receive the down-sampling image from the down-sampling block, and (ii) receive the -th feature map from the -th up-sampling block, and then rescale a size of the -th feature map to be identical to that of the down-sampling image and (iii) apply a summing-up operation to the down-sampling image and the -th rescaled feature map, thereby acquiring the -th feature map and causing, if M is an integer greater than or equal to one, the (2-(M+1))-th up-sampling block to (i) receive the (1-M)-th feature map from the (1-M)-th filter block, and (ii) receive the (2-(M+2))-th feature map from the (2-(M+2))-th up-sampling block, and then rescale a size of the (2-(M+2))-th feature map to be identical to that of the (1-M)-th feature map and (iii) apply a summing-up operation to the (1-M)-th feature map and the (2-(M+2))-th rescaled feature map in order to generate the (2-(M+1))-th feature map, thereby acquiring the (2-k)-th to the -th feature maps, wherein the device, at the step of (c), in case M is an integer greater than or equal to 1 and less than or equal to (k-2), causing the (2-(M+1))-th up-sampling block to perform processes of (i) obtaining an (1-M)-th adjusted feature map whose number of channels is modified by a first filter in the (2-(M+1))-th up-sampling block applying a convolution operation to the (1-M)-th feature map; (ii) obtaining an (2-(M+2))-th adjusted feature map whose number of channels is modified by a second filter in the (2-(M+1))-th up-sampling block applying a convolution operation to the (2-(M+2))-th feature map; and then obtaining the (2-(M+2))-th rescaled feature map by applying an up-sampling operation to the (2-(M+2))-th adjusted feature map; (iii) computing the (1-M)-th adjusted feature map with the (2-(M+2))-th rescaled feature map in order to produce the (2-(M+1))-th feature map; and (iv) relaying to the (2-M)-th up-sampling block the (2-(M+1))-th feature map acquired from the (2-(M+1))-th up-sampling block, thereby acquiring the (2-(k-1))-th to the -th feature maps.