The development of a platform within the framework of ImageJ to process digitally recorded holograms is presented in this work.ImageJ an open source software for processing digital images, provides the needed architecture to develop customized and specialized processing tools of images.In this paper, we show the use of that architecture to develop the needed tools to reconstruct numerically holograms that were digitally recorded.The main advantage of this development is the possibility of using the built--in functions of ImageJ to pre--process the recorded holograms as well as to visualize and manage the reconstructed images.The use of the developed tool is illustrated by means of a step--by--step reconstruction of a digital hologram of a regular die.