1. Introduction
In recent years, the consumer market for home furnishings has displayed robust potential, propelling the rapid growth of the furniture industry and creating a substantial demand for wood and wood products [
1]. In a bid to safeguard forest resources, preserve the ecological environment, and foster a harmonious coexistence of humanity and nature, China initiated an increased emphasis on green homes in 2012. The country introduced a series of policies aimed at promoting the low-carbon home furnishing industry, aligned to top-level planning perspectives. Artificial fast-growing timber, due to its softwood and low density, cannot be directly employed as raw wood products [
2]. It requires modification to enhance its performance and increase stability. This quality-improved artificial timber exhibits robust functionality, has broad applications, and commands high added value [
3]. Recognized as a green and renewable material, Reconstituted Decorative Veneer (RDV), also known as reconstituted wood or the simulation of precious wood, utilizes the principles of bionics. Ordinary wood undergoes advanced processing, restructuring, and landscaping treatments to produce new all-wood materials with superior performance. This approach has garnered international consensus, particularly against the backdrop of energy conservation, emission reduction, and global responses to climate change [
4]. RDV, which has been subjected to artificial wood modification treatments, offers the wood substrate enhanced visual possibilities. This aids in optimizing its performance, effectively meeting the market’s demand for ample timber resources and elevating environmental standards in home materials. As the home furnishing industry undergoes transformation and upgrades, RDV is ready to encounter numerous market opportunities [
5,
6,
7].
Simultaneously, with the younger generation emerging as the predominant consumer demographic, the home furnishing sector has progressively adopted a design trend centered around sensory experiences. This trend caters to the comfort requirements of both the older and newer iterations of consumers. The newer consumer groups, in particular, seek a personalized home environment while also prioritizing overall style and the value of furnishings. Sensory comfort has become a pivotal factor in their decision-making process. The native texture and color of wood materials play a crucial role in generating a sense of empathy and providing a comfortable feeling, both visually and psychologically. In recent years, scarcity in timber resources and escalating prices of wood furniture have led some consumers to compromise on purchasing solid wood products. Instead, they opt for furniture items that emulate solid wood decorative effects. These products rely on techniques such as natural wood grain scanning collection and processing for surface decoration. This includes methods like direct printing of wood grain, wood grain-impregnated paper veneer, and digital wood grain 3D printing. However, a segment of the current market features imitation veneer, wood grain-impregnated paper veneer, digital printing wood grain, and other wood grain techniques that suffer from issues such as unclear patterns, inappropriate color contrasts, and inconsistent visual effects. Consequently, the resulting products lack authentic wood texture and exhibit monotonous colors. This compromises their ability to meet the psychological needs of individuals seeking sensory comfort in indoor spaces.
Existing research on the visual perception of wood materials can be broadly categorized into three focal points, as identified by some scholars: (1) the visual sensations elicited by wood materials; (2) attitudes and preferences (aesthetic evaluation) towards various wood products and (3) emotional and psychophysiological responses to wood perceptions [
8]. Burnard et al. (2017) [
9] conducted an assessment of the disparities in people’s preferences for wood and non-wood environments. Their findings revealed that wood environments received higher audience and preference evaluations. Delving into the literature, Bringslimark et al. (2010) [
10] highlighted that the texture, knots, and timber color of wood materials are crucial surface visual attributes influencing people’s assessment of wood material preferences. It is asserted that factors such as wood species, knots, wood coverage, application form, and spatial location relationships can also impact preference assessments. All these studies underscore that the visual characteristics of timber materials, including color, texture, and luster, directly manifest in the external visual performance of the products to which they are applied. These characteristics serve as a critical reference for users in evaluating a product.
Wood color stands out as the pivotal feature that reflects both the visual and psychological aspects of a material’s surface. In the realm of wood and wood products, wood color serves as the primary characteristic. It not only plays a crucial role in assessing wood quality but also serves as a fundamental criterion for measuring the value of a product. The significance of wood color extends to the design and production of wood products. Traditionally, researchers employed color names or combinations of color names to describe the surface color of wood. The quantitative characterization of wood color; however, became feasible with the development of chromaticity research. Since the 1960s, scientists in the United States, Europe, and Japan have conducted thorough investigations into the quantitative measurement of wood color, yielding fruitful results. Scholars worldwide have consistently highlighted that visual physical quantities, such as color, are primary factors influencing users’ emotional preferences, cognitive load, and eye movements [
11]. As a background material in indoor environments, the visual characteristics of the color of wood materials become a crucial factor affecting people’s psychological impressions [
12,
13]. The color is dependent on the timber color of the substrate and exerts a certain degree of influence on the texture. Jafarian et al. (2018) [
14] explored the relationship between the color of wood veneer and space lighting, concluding that wood veneer with bright colors contributes to enhancing the quality of space lighting, thereby creating a visually comfortable indoor atmosphere. The surface gloss of wood, its light reflection properties, and anisotropy collectively create a varied visual effect. Research has shown that different species of finish gloss, through careful interaction, can produce the desired visual impact for users, thereby enhancing the quality of indoor space and improving lighting ambiance [
15]. Minoru (1987) [
15] found that wood knots and texture, as natural visual physical quantities in wood decorative material, positively impact the visual evaluation of wood. Subsequent studies by Matsumoto et al. (2016) [
16], Broman (2001) [
17], and Manuel et al. (2016) [
18] have reinforced the strong correlation between preference evaluation and the number of knots. Haemaelaeinen et al. (2012) [
19] utilized eye-tracking techniques to experimentally assess the contrast difference on the surface of wood material due to painting, demonstrating a correlation between texture clarity under the influence of coating sheen and the attractiveness and contrast values of the wood material’s surface.
While some studies have affirmed that analyzing a single surface visual, physical quantity of wood can measure its visual properties, the diverse applications of wood on spatial surfaces necessitate a nuanced understanding of how multivariate interactions influence people. Moreover, variations in geographical, national, socio-economic, and cultural contexts can lead to differing perceptions of wood materials. Joel et al. (2019) [
20] utilized a semantic differential approach to assess perceptual preferences for visual and haptic aspects of wood materials among Swedish and Japanese users. They found that Japanese users preferred homogenous wood surfaces, while Swedish users favored wood with textured or knotted surfaces. Ramananantoandro et al. (2013) [
21] discovered that users in Antananarivo, Madagascar, exhibited a significant preference for yellow, darker wood timber colors, based on the CIELab* color model with sensory analysis. They highlighted socio-economic factors as influencing color preferences. Strobel et al. (2017) [
22] asserted that cultural expectations can also significantly impact the perception of wood materials. When evaluating people’s physiological responses to the visual properties of wood-based materials, commonly used indicators include brain activity, autonomic activity, endocrine activity, and immune system activity. Early overseas research often used blood pressure, heart rate, and pulse rate as physiological evaluation indices. Takeshi et al. (1998) [
23] conducted experiments demonstrating that wood affects pulse rate and systolic blood pressure changes more than silk and other materials. Subsequent studies (Satoshi, 2008 [
24]; Yuko et al., 2002 [
25]) combined human heart rate, blood pressure, and subjective evaluation indices, concluding that individuals in spaces with wooden decorative backdrops had significantly lower blood pressure and fewer negative emotions than those facing backdrops made of other materials. In addition to physiological signals, the collection of eye movements and EEG, skin conductivity, salivary cortisol, heart rate variability, and other physiological indicators are gradually becoming evaluation indices for determining visual perception of wood materials [
26]. Infrared-based non-contact perception determination methods are also under further development. Visual perception, distinct from vision, encompasses not only the direct stimuli produced by visual senses to the external world but also invokes memories and experiences stored in the brain [
27]. The visual properties of wood materials can directly impact human mental health. For instance, changes in wood color can alter perceptions of light and dark, warmth and cold, while changes in texture can influence perceptions of strength and weakness, likes and dislikes [
28,
29]. Wang et al. (2015) [
30] utilized the semantic differential method to divide college students’ sensory properties and quantitative evaluations of 28 finish patterns into three dimensions. The results indicated that patterns with rich color variations differed in visual properties, providing a more sensual and elegant feeling in the sensory dimension. Over 90% of decorative veneers were considered to possess “natural-practical” and “man-made-decorative” characteristics in the evaluation dimension [
31,
32,
33,
34].
1.1. Contributions
Enriching theoretical and experimental research on visual perception in veneer. There needs to be more studies on visual perception in veneer. In this study, we investigate qualitatively and quantitatively the relationship between color and visual perception of reconstituted decorative veneer and gain a deeper understanding of the logic of visual perception as an evaluation criterion in the design of home finishes. The design and application strategies and key points are sorted out further to expand the theory of visual perception in experimental research.
It is improving RDV’s decorative properties and visual aesthetics. Visual perception is an essential part of the study of RDV, involving the visual sensory experience and aesthetic performance of its application products and environment. It directly affects the spatial atmosphere people perceive and is closely related to the attractiveness of home products. Exploring the visual perception characteristics of RDV plays a crucial role in improving the visual aesthetics and decorative performance of veneers.
Promote the application of reconstituted decorative lamellas and other new materials and technologies in home décor. Materials and their decorative properties are the most essential material support for creating a comfortable environment. Developing new finishing materials can promote the design innovation of home furnishing products and enrich the varieties of home furnishing materials. To transform and upgrade the home furnishing industry, it should shift from the pure pursuit of precious wood to developing new alternative materials. Therefore, it is necessary to systematically study the restructuring of decorative materials, develop home finishing products that are popular in the market, and create conditions for the large-scale application of reconstituted decorative veneer in the home industry. At the same time, it is also of reference significance for using other new materials for home decoration.
1.2. Paper Outline
The purpose of this paper is to explore the visual perceptual relationship between color and texture in RDV. Specific sections are described below: The second chapter focuses on the methodology, which is based on the theory of color blending and sample clustering for the color and texture of RDV.
Section 3 focuses on a set of visual perception experiments with RDV: selecting 22 texture types and varying their color palettes for eye-tracking experiments.
Section 4 analyses and discusses the experimental data.
Section 5 concludes the study.
5. Conclusions
This study adopts a combination of eye-tracking tests and subjective preference research. Firstly, three objective indicators of subjects’ gaze duration, the number of gaze times and time of first gaze were used to analyze and compare subjects’ visual attention to images of RDV with different color palettes and texture types in conjunction with hotspot diagrams. Secondly, the subjective questionnaire data were quantitatively evaluated and compared. Once again, combining subjective and objective data, the relationship between objective eye movement indexes and overall evaluation was verified, and the reliability and accuracy of the analysis conclusions were clarified. The results of this experiment provide scientific and rational experimental reference bases for assisting in the design of the color-mixing methods and texture types of RDV. This experiment obtained the following conclusions based on the data analysis:
(1) There is a high degree of consistency between the subjects’ gaze duration, gaze counts and hotspot maps. There is a significant difference between the gaze indicators and the color mixing modes, amongst which asymmetric oblique mixing, high luminance circumferential mixing, and vertical mixing are ranked at the top of the gaze indicators and all receive a high degree of attention. In contrast, radial mixing and low luminance circumferential mixing are ranked at the bottom of the gaze indicators and receive less attention. In the first gaze time, the maximum value is generally distributed in the interest area of radial tonality and low luminance circumferential tonality. Combining the results of the first three gaze indicators with the later subjective questionnaire study, it can be found that this result is caused by the fact that the colors in the radial tonality and low luminance circumferential tonality color groups are all low luminance and have a single level of color structure, which results in the subjects not being able to differentiate between the texture and the colors in the experimental images. The difficulty in extracting relevant color and texture information increased, and the first gaze time was longer.
(2) Subjective preference for the experimental samples differed significantly from the color blending method, while the relationship with texture type was insignificant. The experimental images with asymmetric oblique toning, high luminance circumferential toning, and vertical toning had the highest subjective ratings and degree of liking. In contrast, the experimental images with low luminance circumferential and radial toning had the lowest subjective ratings and lower degrees of liking. This result has some commonality with the results of the eye-tracking test, which laterally reflects that the gaze metrics can quantify the visual attractiveness of the RDV images to a certain extent.
(3) The correlation analyses among the three data groups, namely, gaze duration, gaze counts and preference, all showed positive correlations. Among them, the correlation between the two attention indicators of gaze duration and number of times of gaze showed significant differences. The analysis of the common law of combining images with a high degree of attention revealed that the stronger the stimuli, such as high brightness, strong contrast, and color hierarchy, the higher the level of attention was. However, the correlation between the two attention indicators and the subjective preference scores is average, indicating that the objective attention indicators do not accurately reflect the subjects’ preferences. It would be more effective to analyze the subjects’ attention and preference by combining the eye-tracking measurement technique and the subjective evaluation method when evaluating the visual perception of the RDV.
This study, delving into the color and texture characteristics of RDV from the perspective of visual perception, offers valuable insights for the development and design of new products in this field. However, there are some limitations and challenges that should be acknowledged:
(1) Limited the Population and Experimental Material: The main population in the experiment was set between the ages of 20∼26 years old, which could be more relaxed and subdivided into age groups in subsequent studies. It is important to pay attention to the preference bias of different age groups. In the form of experimental materials, pictures were used to differentiate between colors and textures. In the subsequent research, can use the physical form, increase the texture and other conditions to enrich the choice of experimental materials, closer to the actual life.
(2) Limited Experimentation Variables: The visual perception experiment utilized eye-tracking devices for data acquisition. To enhance the scientific rigor, future studies might consider incorporating additional parameters such as EEG and heart rate. Moreover, the experiment focused on two variables—color mixing mode and texture type. Exploring other potential influencing variables like color area, color position relationship, and texture size could provide a more nuanced understanding of users’ visual perception.
(3) Limited Theoretical Research Depth: The theoretical research section has a relatively small number of studies related to visual perception, and there is room for improvement in the depth of research. Strengthening the foundational theoretical knowledge and expanding the scope of related literature studies could enhance the overall theoretical framework.
(4) Multidisciplinary Complexity: The design of recombinant decorative thin wood involves a multidisciplinary approach, integrating art, timber science, and furniture manufacturing technology. While this study focuses on color and texture, other crucial factors such as gloss characteristics, scale, and application range have not been thoroughly explored. Future research could delve into these aspects to ensure a comprehensive understanding.