Ruimin Lyu, School of Artificial Intelligence and Computer Science, Jiangnan University, China
Tianqin Zhang, School of Artificial Intelligence and Computer Science, Jiangnan University, China
Zhaolin Yuan, School of Artificial Intelligence and Computer Science, Jiangnan University, China
Proc. ACM Comput. Graph. Interact. Tech., Vol. 4, No. 2, Article 20. Publication date: August 2021.DOI: https://doi.org/10.1145/3465625
Abstract: When viewing visual artworks, one can feel the suggestive movement from the brushstrokes. This phenomenon has been recorded widely in literature on art theory, and its physiological basis has been found in neuroaesthetic studies, but there is no method to measure its details at present. In this paper, two experiments are designed to measure the velocity sense and the trace sense, which are the instantaneous and cumulative representations of the same content—the kinetic feeling of strokes, respectively. Furthermore, various visualizations are designed for the two kinds of experimental data as artistic recreation of traditional artworks. In addition, the quantitative analysis is performed on the imaginary stroke movement, showing that imaginary stroke movement can be studied by mathematics.
CCS Concepts: • Applied computing → Fine arts; • Human-centered computing → Visualization design and evaluation methods; • Human-centered computing → Visualization application domains;
**Additional Keywords and Phrases:**Brushstroke,
Empirical aesthetics,
Visualization,
Embodied Simulation,
Embodied Aesthetics
ACM Reference Format: Ruimin Lyu, Tianqin Zhang, and Zhaolin Yuan. 2021. Imaginary Stroke Movement Measurement and Visualization. Proc. ACM Comput. Graph. Interact. Tech. 4, 2, Article 20 (August 2021), 13 pages. https://doi.org/10.1145/3465625
Beholders can subjectively reconstruct “imaginary stroke movement” from static brushstrokes on visual artworks (Figure 1). This psychological phenomenon has been recorded in lots of art literature, and is classified as one important perceptual mode of “embodied aesthetics” [Freedberg and Gallese, 2007; Gallese, 2019]. In modern times, many artists tried consciously or subconsciously to express in unique brushstrokes, such as Monet, Van Gogh, and Jackson Pollock. In traditional eastern painting theory, the concept of “brush and ink” takes an important position that emphasizes the expressiveness of brushstrokes. In eastern calligraphy, strokes must be performed in a certain order to form highly sequential content and thus the beholder can connect them into coherent actions, which is regarded as a unique feature of calligraphy [Ledderose, 1980]. Imaginary stroke movement is a varied phenomenon in visual arts, which makes us wonder whether it can be studied scientifically.
Fig. 1. The aims of this study: “can we quantify, analyze and make use of imaginary stroke movement?” (© Ruimin Lyu)
Related studies have been conducted in the area of experimental aesthetics, especially in neuroaesthetics [Chatterjee and Vartanian, 2016]. Knoblich found that the observation of static graphic symbols evokes the motion simulation of the gestures needed to produce the symbols [Knoblich et al., 2002]. Through EEG, Umiltà [Umiltà et al., 2012] and Sbriscia-Fioretti [Sbriscia-Fioretti et al., 2013] showed that the brain's motor system is actively involved in the aesthetic behavior when viewing Lucio Fontana's and Franz Kline's abstract paintings composed of unique brushstrokes. Ticini found that consciously imitating the artist's actions when viewing artworks can enhance the aesthetic experience [Ticini et al., 2014]. All studies involve the measurement of imaginary stroke movement, and the objects of measurement are mainly about the aesthetic preference and brain nerve activity, which can be regarded as the “result” and “hardware.” However, the “detailed content” is ignored. This becomes the core issue of this study—(Q1) to acquire the detailed content of imaginary stroke movement as data.
We draw lessons from the description of motion in physics, and regard that the imaginary stroke movement can be represented in “dual” ways: velocity sense and trace sense, which mean the instantaneous feeling and the cumulative effect of imaginary reconstruction of stroke motion, respectively. As for the measurement method, the current technology cannot directly fetch the imaginary movement in the brain, so it can only take the way of self-report. Aesthetic scales are the most commonly used self-report measurement [Palmer et al., 2012; Schindler et al., 2017], but it can only obtain scores of certain indicators, rather than complex motion perception data. Fortunately, the common practice of “copying” in traditional calligraphy and painting can be seen as enhanced “stroke imitation” since it requires the trainer to imagine the stroke movement purposefully and imitate it completely, and its result can be taken as the trainer's active output of imaginary stroke movement. Therefore, we simplified the “copying” behavior and thus designed two experiments to collect data of the velocity sense and trace sense, which are mainly discussed in section 2.
Based on the acquired data of the imaginary stroke movement, we try achieving various forms of visualization with different trade-offs on three groups of quality indicators. These visual works show that the quantification of imaginary stroke movement opens a gate for two beneficial exploration directions: (Q2) artistic re-creation based on the data of imaginary stroke movement and (Q3) style classification based on imaginary stroke movement measurement, which are mainly discussed in sections 3 and 4, respectively.
The imaginary stroke movement is the subjective simulation of physical movement, and thus we can draw lessons from the representation of movement in physics. In Newton's idea, by omitting the details of the moving object, movement can be simplified as “pure movement,” which can be quantitatively described by the dual computations—differential and integral. Drawing lessons from his idea, we omit the “object” of subjective stroke motion, that is, color, texture, and so on, and consider only the pure “motion,” and express it in two measurable representations (Figure 2):