基于情感的灰度图彩色化
Affective Image Colorization
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摘要: 灰度图彩色化一直备受关注.颜色不仅能增强图像的表现力,而且是情感表达 的主要媒介.美术上常用配色方案(color theme)来表示图像的颜色构成.之前大部 分研究关注上色的结果是否符合图像语义内容,却很少考虑图像所表达的整体情感. 在自动彩色化时,同时保证语义正确以及情感符合用户需要无疑是一个挑战.在本文 中,我们提出了一套基于情感的灰度图彩色化系统.系统仅仅需要用户辅助图像分割 并给每个分割对象一个标签,以及输入一个情感词,用于指导上色的配色方案.首 先,根据标签从网上下载图像,过滤得到符合语义的参考图.然后,根据情感词,我 们基于美学原理选出一些配色方案.以这些配色方案为指导,使用遗传算法为每个对 象最终确定一幅参考图.我们提出了一种混合的纹理合成方法用于最后着色.据我们 所知,这是第一个以情感为指导,同时考虑语义的灰度图彩色化系统.同时实验证明 了系统的有效性,特别是与之前基于 MRF 的方法相比有明显优势.Abstract: Colorization of gray-scale images has attracted many attentions for a long time. An important role of image color is the conveyer of emotions (through color themes). The colorization with an undesired color theme is less useful, even it is semantically correct. However this has been rarely considered. Automatic colorization respecting both the semantics and the emotions is undoubtedly a challenge. In this paper, we propose a complete system for affective image colorization. We only need the user to assist object segmentation along with text labels and an affective word. First, the text labels along with other object characters are jointly used to filter the internet images to give each object a set of semantically correct reference images. Second, we select a set of color themes according to the affective word based on art theories. With these themes, a generic algorithm is used to select the best reference for each object, balancing various requirements. Finally, we propose a hybrid texture synthesis approach for colorization. To the best of our knowledge, it is the first system which is able to efficiently colorize a gray-scale image semantically by an emotionally controllable fashion. Our experiments show the effectiveness of our system, especially the benefit compared with the previous Markov random field (MRF) based method.