Recently, with the increasing interest in three-dimensional (3D) images, there has been a demand for solving the problems of discomfort, dizziness, etc., related to a stereo or multi-view 3D image. Therefore, research on holograms, which can realize perfect 3D imaging, has become more active. However, the high cost of generating holograms is a challenge [1]. In order to make the contents of digital holograms continuous and widespread, rather than using them as entertainment for a one-off event, it is necessary to diversify these contents. Therefore, we need to author hologram contents efficiently in order to reduce the cost and effort of content development as well as the authoring time, and to create hologram convergence contents that are applicable to various industrial fields [2]. Accordingly, a study on how to author hologram contents, such as producing hologram videos using one sheet of holograms, has been conducted previously. Currently, the development of a 3D broadcasting technology using digital holography is underway at MIT in the USA, at NHK

In this paper, we propose a new subband quantizer which is a type of quad-tree for applying to digital hologram compression based on Fresenelet transform. After executing Fresnelet transform to the captured digital holgoram, we analyze effect of the designed quantizer for the reconstructed objects from analyzing average energy of each coefficient and visual importance in all subbands. We analyze distribution of coefficient and set dynamic range for each subband, and then design subband quantizer. For enhancing effectiveness of the designed quantize, we adopt a method using the coefficients which are located out of dynamic range, which are named by exception indices. From this, we can obtain more effective quantizer which has higher performance in a range of σ′ = 5.0.키워드 : 디지털 홀로그램, 압축, 쿼드-트리, 프레넬릿 변환