A learning method for generating integrated object detection information of an integrated image by integrating first object detection information and second object detection information is provided. The method includes steps of: (a) a learning device, if the first object detection information and the second object detection information is acquired, instructing a concatenating network included in a DNN to generate pair feature vectors including information on pairs of first original ROIs and second original ROIs; (b) the learning device instructing a determining network included in the DNN to apply FC operations to the pair feature vectors, to thereby generate (i) determination vectors and (ii) box regression vectors; (c) the learning device instructing a loss unit to generate an integrated loss, and performing backpropagation processes by using the integrated loss, to thereby learn at least part of parameters included in the DNN.