SUMAC 2025 is the 7th edition of the workshop on analySis, Understanding and proMotion of heritAge Contents. It is held in Dublin, Ireland, on 27 October and is co-located with the 33rd ACM International Conference on Multimedia. The workshop's objective is to present and discuss the latest and most significant trends, challenges, and advances in the fields of machine learning, signal processing, multimodal techniques, and human-machine interaction. The workshop is dedicated to the valorization of cultural heritage, with an emphasis on unlocking and access to the big data of the past. A representative scope of Computer Science methodologies dedicated to the processing of multimedia heritage contents and their exploitation is covered by the works presented, with the ambition of advancing and raising awareness about this fully developing research field.

The term “aesthetic experience” corresponds to the inner state of a person exposed to the form and content of artistic objects. Quantifying and interpreting the aesthetic experience of people in different contexts can contribute towards (a) creating context and (b) better understanding people’s affective reactions to different aesthetic stimuli. Focusing on different types of artistic content, such as movies, music, literature, urban art, ancient artwork, and modern interactive technology, the goal of this workshop is to enhance the interdisciplinary collaboration among researchers coming from the following domains: affective computing, aesthetics, human-robot/computer interaction, digital archaeology and art, culture, addictive games.

The term “aesthetic experience” corresponds to inner states of individuals exposed to art. Investigating form, content, and aesthetic values of artistic objects, indoor and outdoor spaces, urban areas, and modern interactive technology is essential to improve social behaviour, quality of life, and health of humans in the long term. Quantifying and interpreting the aesthetic experience of art receivers in different contexts can contribute towards (a) creating art and (b) better understanding humans’ affective reactions to aesthetic stimuli. Focusing on different types of artistic content, such as movies, music, urban art, ancient artwork, and modern interactive technology, the goal of the Second International Workshop on Multimodal Affect and Aesthetic Experience is to enhance the interdisciplinary collaboration among researchers from the following domains: affective computing, aesthetics, human-robot interaction, and digital archaeology and art.

We present an approach for unsupervised computation of local shape descriptors, which relies on the use of linear autoencoders for characterizing local regions of complex shapes. The proposed approach responds to the need for a robust scheme to index binary images using local descriptors, which arises when only few examples of the complete images are available for training, thus making inaccurate the learning process of parameters of traditional neural networks schemes. Given the possibility of using linear operations during the encoding phase, the computation of the proposed local descriptor can be fast once the parameters of the encoding function are learned. After conducting a vast search, we identified the optimal dimensionality of the resulting local descriptor to be of only 128 dimensions, which allows for efficient further operations on them, such as the construction of bag representations with purposes of shape retrieval and classification. We evaluated the proposed approach indexing a collection of complex binary images, whose instances contain compounds of hieroglyphs from the ancient Maya civilization. Our retrieval experiments show that the proposed approach achieves competitive retrieval performance when compared with hand-crafted local descriptors.

In this paper, we study oracle character recognition and general sketch recognition. First, a data set of oracle characters, which are the oldest hieroglyphs in China yet remain a part of modern Chinese characters, is collected for analysis. Second, typical visual representations in shape- and sketch-related works are evaluated. We analyze the problems suffered when addressing these representations and determine several representation design criteria. Based on the analysis, we propose a novel hierarchical representation that combines a Gabor-related low-level representation and a sparse-encoder-related mid-level representation. Extensive experiments show the effectiveness of the proposed representation in both oracle character recognition and general sketch recognition. The proposed representation is also complementary to convolutional neural network (CNN)-based models. We introduce a solution to combine the proposed representation with CNN-based models, and achieve better performances over both approaches. This solution has beaten humans at recognizing general sketches.

This paper presents a new methodology for the automatic estimation of the optimal amount of visual words that can be removed from a visual dictionary, such that no harm is induced in the discriminative potential of the resulting bag-of-visual-words representations. The proposed approach relies on a special definition of the entropy of each visual word when considered as a random variable, and a new definition of the overlap of class models computed with a normalized Bhattacharyya coefficient. We combined our proposed methodology with a recent approach that labels visual words as stop-words showing that this combination is beneficial to reduce the dimensionality of bag representations, while obtaining good results in terms of classification accuracy and retrieval performance.

Archaeologists often spend significant time looking at traditional printed catalogs to identify and classify historical images. Our collaborative efforts between archaeologists and multimedia researchers seek to develop a tool to retrieve two specific types of ancient Maya visual information: hieroglyphs and iconographic elements. Towards that goal we present two contributions in this paper. The first one is the introduction and analysis of a new dataset of 3400+ Maya hieroglyphs, whose compilation involved manual search, annotation and segmentation by experts. This dataset presents several challenges for visual description and automatic retrieval as it is rich in complex visual details. The second and main contribution is the in-depth analysis of the Histogram Of Orientation Shape Context (HOOSC), and more precisely, the development of 4 improvements that were designed to handle the visual complexity of Maya hieroglyphs: open contours, mixture of thick and thin lines, hatches, large instance variability, and a variety of internal details. Experiments demonstrate that the adequate combination of our improvements to retrieve Maya hieroglyphs, provides results with roughly 20% more precision compared to the original HOOSC descriptor. Complementary results with the MPEG-7 shape dataset validate (or not) the proposed improvements, showing that the design of appropriate descriptors depends on the nature of the shapes one deals with.