Color Research and Application最新文献

The development of imaging technologies allows personal electronic devices to have telephoto and close-up cameras. The images captured by these cameras sometimes are dominated by a single color (i.e., pure color images). In our earlier work, the PolyU Pure Color dataset was collected and the Pure Color Constancy (PCC) method was proposed, which was the first study investigating color constancy for pure color images. In order to make the method more robust, especially when the images are not as extreme as those included in the PolyU Pure Color dataset, an edge-aware Pure Color Constancy (ePCC) method is proposed in this article. It adopts a similar architecture as the PCC method, with four additional color features derived from the edge map of an image as the input. Moreover, the PolyU Pure Color dataset V2 was collected. It includes 1271 images, which are not as extreme as those in the PolyU Pure Color dataset V1 and cover a wider range of illuminant colors. The proposed ePCC method was found to have better performance than the PCC method on pure color images, reducing the angular error by 10% with slight increases in the number of parameters and computational resources. Moreover, the ePCC method also resulted in comparable performance to the various state-of-the-art learning-based methods on images of normal scenes.

Color information plays a key role in cognitive regulation and the allocation of attentional resources. However, the influence of binocular color rivalry on prefrontal cortex (PFC) activation has not been systematically investigated. To address this, we employed functional near-infrared spectroscopy (fNIRS) to examine oxygenated hemoglobin (HbO) responses in the PFC elicited by four binocular rivalry color pairs: red-green (R-G), yellow-blue (Y-B), orange-cyan (RY-GB), and purple-yellow green (RB-YG). The results showed that all color pairs induced significant activation in the PFC, particularly in Brodmann areas 9 (BA9) and 10 (BA10). The R-G condition activated both regions, whereas Y-B primarily activated BA10. Further regression analysis revealed significant differences in the activation patterns of L, M, and S cone cells across the color pairs, which were positively correlated with changes in HbO concentration in the PFC. In summary, this study reveals the hemodynamic response characteristics of the PFC during binocular color rivalry and their association with retinal cone activation, providing novel empirical evidence for understanding the neural mechanisms underlying visual rivalry.

Illuminant estimation in camera color space is a critical step in the image signal processing pipeline, which is commonly performed based on the RGB RAW images captured by a camera. Recently, most smartphones are equipped with an ambient light sensor (ALS) around the camera. In this work, we propose an illuminant estimation method (i.e., RACC) using both RGB RAW images and ALS signals as the inputs. A large dataset containing both RGB RAW images and ALS signals of more than 1300 scenes was collected, which was used to develop and evaluate the proposed RACC method. The results show that the RACC method results in much smaller angular errors and requires much fewer computational resources. In particular, the method was designed with a training mechanism to consider a practical challenge of incomplete or missing ALS signals under low light conditions, which was verified to have stable performance. These clearly suggest that the RACC method can be deployed for practical applications.

As a visual cultural symbol, color represents the collective aesthetics and the ethnic cohesion of an ethnic group. This study takes the Changning Miao costume as an object, aiming to analyze the role and mechanism of the costume color system in cultural evolution. We employed a three-stage K-means clustering method for color extraction. Key findings included: (1) Color shows an obvious correlation with materials and techniques, serving as explicit indicators of cultural evolution. (2) The color system of Changning Miao costumes contributes independently to its collective aesthetic, following the hierarchical color-matching rules of primary color dominance and secondary color subordination. By building a color database for Changning Miao costumes, we provide a data-driven quantitative tool for cultural preservation. The three-stage clustering method overcomes the limitations of unidimensional analysis, establishing a model that bridges visual perception to selection behavior, facilitating the adaptive inheritance of traditional wisdom in modern contexts.

Vision constitutes the primary channel for human environmental perception. The visual aesthetic perception of plant color landscape can be evaluated through two dimensions: subjective experience and theoretical analysis, represented by the independent variables: “Scenic Beauty” and “Color Harmony Beauty” respectively. Each has its own focus, but few studies have explored the relationship between the two. Combining scenic beauty estimation (SBE) and M–S Color harmony beauty estimation, this study quantitatively analyzed the relationship between the color characteristics and visual aesthetics of autumn plant communities. The results showed: (1) Scenic beauty was primarily driven by color-leafed index, ratio of primary color, ratio of primary hue, brightness index, and saturation index; Color harmony beauty was predominantly influenced by number of colors, color diversity index, color evenness index, and hue index. These two sets of key indicators did not overlap or conflict and jointly expressed the characteristics of plant colors in terms of attributes, layout, and structure. (2) Significant positive correlation existed between Scenic Beauty values and M–S Color Harmony Beauty values, and their mean values decreased with the decrease of each other's level as a whole. (3) The 15 visually aesthetic dominant communities were classified into three types: multi-color compound type, warm color dominant type, and warm-cool color contrast type. The design guidelines of the three types of autumn plant community color landscapes were developed correspondingly. This research advances novel paradigms for quantitative landscape evaluation and provides evidence-based design methodologies.

The objective of this work was to evaluate the chromatic displacement due to successive dilutions of different colorants in transparent liquid systems. The solutions were diluted to cover the entire range of transmittance values, from transmittance approaching zero (close to the black achromatic point) to nearly 100% (white achromatic point). Nine colorants, covering a wide range of hue values, were employed; the transmittance of the solutions was spectrophotometrically measured in the visible range, and the tristimulus values were calculated for illuminant D65. 3D representations in CIE, CIELAB, and CIELUV spaces were performed, along with the corresponding planar projections. Besides the expected lightness increase, as the concentration of a given colorant decreased, saturation (in the CIELUV space) and chroma (in the CIELAB space) increased up to a given value and then decreased. Colorants' dilution led to different trajectories in the chromaticity diagram, causing perceived changes of saturation and hue attributes, slightly correlated with the dominant wavelength shift. These phenomena have been previously observed in opaque systems and in lights and were much less studied in transparent colorant formulations, which are relevant for applications such as glass, films, plastics, or colorant solutions. Some definitions involving concentration as related to change in color attributes, such as the optimal lightness to chroma or saturation ratio and the trajectory change in the chromaticity diagram, are proposed.

Batch-to-batch variations in substrates and primary inks pose significant challenges in spot color printing, often resulting in noticeable color inconsistencies despite consistent ink formulations. Existing solutions typically require recalculating optical properties for each new batch, a process that is both time-consuming and resource-intensive. This study proposes a formulation correction method based on the single-constant Kubelka–Munk (KM) theory that compensates for batch-induced deviations in the absorption-to-scattering (K/S) ratio. By utilizing the optical constants derived from a benchmark batch, the method estimates the K/S discrepancy caused by new batches and corrects the ink formulation accordingly, avoiding the need to remeasure optical properties. Experiments were conducted on five target spot colors using two batches of gravure inks and uncoated paper substrates. The proposed method improved color reproduction accuracy, reducing the average CIE ΔE from 2.05 to 0.97 and the RMSE of spectral reflectance across samples. Four out of five corrected samples achieved ΔE values below 1, indicating excellent visual consistency. This method offers a practical and efficient solution for maintaining high-fidelity spot color reproduction in industrial printing workflows.

As lighting technologies become increasingly tunable and user-driven, understanding how individuals engage with color and light properties in context-sensitive ways is critical. This study introduces a novel experimental framework that combines direct user agency with eye-level spectral measurements to examine lighting preferences in realistic interior environments. Twenty-five participants customized illuminance, correlated color temperature, and chromaticity across six scenarios varying by environmental context (home vs. work office) and psychological intent (relaxation vs. stimulation). Measuring lighting conditions at participants' eye level, rather than at traditional fixed measurement points, accurately captures the spectral environment participants experienced during preference formation. Results indicated significantly higher illuminance and cooler CCT preferences for work-related scenarios compared to home environments, along with individualized chromatic shifts clearly aligned with psychological intent. All participants performed perceptible and intentional chromaticity adjustments between relaxing and energetic settings, although the direction of these changes varied notably across individuals. These findings validate the effectiveness of this methodological framework in capturing context-sensitive lighting behaviors while underscoring the limitations of generalized color prescriptions. The results highlight the importance of adaptive, user-controlled lighting systems that accommodate diverse functional and psychological needs, thus contributing to evidence-based lighting design through detailed insights into how environmental context and psychological intention shape perceptual preferences in realistic settings.