This paper proposes an extraction method of handwritten characters written on printed documents using maxout filter networks. Character extraction from document images, e.g. printed text with handwritten annotation, plays important roles in the field of document analysis and recognition. In this paper, maxout filters that are composed of the maxout activation functions are trained and applied to the extraction of handwritten characters from documents. The maxout filter for the extraction can be regarded as an extension of the morphological closing filter, which can eliminate the valleys of the intensity surface of images. For the extraction of handwritten characters, the parameters of maxout filters are trained to eliminate only the printed characters, which appear as the valleys in an image. In order to handle multiple writers, a batch learning method that trains the parameters by averaging the gradients of the squared errors of each writer is introduced. Moreover, a novel network configuration that has a skipping path is introduced to improve the learning rate and the quality of the extracted images. In the experiments, the extraction of handwritten annotation from document images is demonstrated. The comparison results with the conventional network show the advantage of the proposed network.

This paper reports the 18th Visual Information Processing Camp (VIP Camp) held in Saitama Prefectural Citizen’s Activities General Center from 22th to 24th, September 2018. The VIP Camp is taken place for the students who study visual information processing and other related research fields. The VIP Camp is planned and operated every year by voluntary university students from all over Japan. The primary purpose of the Camp is to provide opportunities for practicing their research presentations and face-to-face discussion on them. The catchword of the Camp this year is “Let’s Start Study”. As represented by the catchword, we, the organizing committee, arranged poster sessions with fast-forward presentations. We also arranged a group work session in which the participants read and discuss research papers presented in leading international conferences. In this paper, we report the planning and organizing activities for the 18th VIP Camp and discuss possibilities to improve the future VIP Camps by analyzing the answers in participant questionnaires.