Non-photorealistic rendering with spot colour

Colour is an important aspect of art. Not only does it give richness to images, but it always provides a means to highlight certain objects. This idea of spot colour has been used extensively in both fine art and commercial illustrations. Many non-photorealistic rendering (NPR) algorithms produce grayscale or monochromatic images with low saturations. In this paper we introduce the idea of spot colour to NPR and propose a simple and automatic algorithm to add spot colour to these rendering styles. The hue is thresholded into colour layers and the most appropriate layer is automatically determined based on factors such as layer region shape and salience. We also consider using an edge-based criterion to colourise the background, which is an effective means of making the foreground stand out. We demonstrate the effectiveness of our approach by adding spot colour to a diverse set of NPR styles

Non-photorealistic rendering with spot colour

Colour is an important aspect of art. Not only does it give richness to images, but it always provides a means to highlight certain objects. This idea of spot colour has been used extensively in both fine art and commercial illustrations. Many non-photorealistic rendering (NPR) algorithms produce grayscale or monochromatic images with low saturations. In this paper we introduce the idea of spot colour to NPR and propose a simple and automatic algorithm to add spot colour to these rendering styles. The hue is thresholded into colour layers and the most appropriate layer is automatically determined based on factors such as layer region shape and salience. We also consider using an edge-based criterion to colourise the background, which is an effective means of making the foreground stand out. We demonstrate the effectiveness of our approach by adding spot colour to a diverse set of NPR styles

Influence of color in a lactation room on users affective impressions and preferences

[EN] Objective: The present study aims to examine the influence of environmental color hue in a lactation room at a health center on users' affective response and preference. Background: Hospital design plays an important role in the emotional experience of patients. In this regard, many studies have attempted to find relationships between design variables and healthcare facilities users' response. Color has been frequently examined because it is always present in the environment and can be easily changed. However, most of the studies dealing with color-emotion relationships acquire users' affective response by questionnaires developed by experts which could lead to inaccurate results since nonexperts may misunderstand concepts set by experts and use nonimmersive images to simulate the environments to assess. Methods: To overcome these limitations, a Kansei Engineering-based approach was proposed. In the first phase, users' specific affective factors for lactation rooms were determined using Semantic Differential. In the second phase, the influence of nine different color hues on users' affective factors was obtained. An immersive display system was used to visualize the room altering hues in an isolated and controlled way. Results: (1) Six user's affective factors connected to the lactation rooms were discovered: safety, elegance, coziness, spaciousness, simplicity, and luminosity, of which coziness has the most impact on the assessment of the room. (2) Warm colors like orange and yellow tend to score highly for coziness which puts them in leading positions when users' assess lactation rooms. Conclusions: Results provide recommendations for designers and show the advantages of using semantic differential and immersive displays to analyze user's affective response to environments.The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Ministerio de Economia y Competitividad. Spain [Project TIN2013-45736-R].López-Tarruella, J.; Llinares Millán, MDC.; Serra Lluch, J.; Iñarra Abad, S.; Wijk, H. (2019). Influence of color in a lactation room on users affective impressions and preferences. HERD Health Environments Research & Design Journal. 12(2):55-70. https://doi.org/10.1177/19375867187965935570122Codinhoto, R., Tzortzopoulos, P., Kagioglou, M., Aouad, G., & Cooper, R. (2009). The impacts of the built environment on health outcomes. Facilities, 27(3/4), 138-151. doi:10.1108/02632770910933152Dalke, H., Little, J., Niemann, E., Camgoz, N., Steadman, G., Hill, S., & Stott, L. 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PaletteNeRF: Palette-based Color Editing for NeRFs

Neural Radiance Field (NeRF) is a powerful tool to faithfully generate novel views for scenes with only sparse captured images. Despite its strong capability for representing 3D scenes and their appearance, its editing ability is very limited. In this paper, we propose a simple but effective extension of vanilla NeRF, named PaletteNeRF, to enable efficient color editing on NeRF-represented scenes. Motivated by recent palette-based image decomposition works, we approximate each pixel color as a sum of palette colors modulated by additive weights. Instead of predicting pixel colors as in vanilla NeRFs, our method predicts additive weights. The underlying NeRF backbone could also be replaced with more recent NeRF models such as KiloNeRF to achieve real-time editing. Experimental results demonstrate that our method achieves efficient, view-consistent, and artifact-free color editing on a wide range of NeRF-represented scenes.Comment: 12 pages, 10 figure