# The Application of Fuzzy Theory in the Evaluation of Visual Images of Smartphone Rear Cameras
## 1 Introduction  
The use of smartphones is currently almost ubiquitous. According to the applications of smartphones in our daily lives, their functions have been divided into the following categories: productivity--emails; information searching--news website browsing; social interacting--social media; leisure and entertainment--games; and transactions--shopping history checking, etc. [1]. In a Pew Research study [2], 46 percent of smartphone users expressed that they could not live without a smartphone. Statistics indicate that the average smartphone owning ratio across the globe is 43 percent, and in the United States, it is 72 percent [3]. It is also estimated that over 5 billion people in the world possess mobile devices, more than half of which are smartphones [4]. With the evolution of fifth generation (5G) networks, smartphones are able to assist users and realize more potential in the Internet of Things (IOT), and in education, entertainment and mobile payments [5; 6; 7]. Through one experiment, it was found that price, brand preference, social impact and features affect consumer decision-making regarding smartphone purchasing, yet online surfing and demands on Wireless Fidelity (Wi-Fi) facilities result in users caring less about the price of smartphones [8]. However, with the evolution of technologies--various technical challenges have disappeared--smart devices have transformed rapidly, and function is no longer the dominant aspect in terms of consumer decision-making. The research of [PERSON] and [PERSON] [9] has also indicated that it is the psychographic factors that impact consumer buying willingness the most. The brands in the market are varied, and the options available to users are increasingly plentiful. Besides users' demands regarding functions, the aesthetic perceptions and psychographic impacts exerted by outside shaping and images are also matters of great importance. There exist a great many brands and kinds of smartphones. In Taiwan alone, there are a dozen brands on the market, all with certain differences in the form of the rear camera. Designs of different types may stimulate different consumer feelings, which further affect their preferences for forms [10]. In the design and development of new products, which are based on designers' past experience and aesthetic feelings, there might exist a gap between consumer and designer feelings. Users may have a different product image perception from that of designers, which would directly influence their degree of fondness for products. Therefore, an objective scheme for analysis and research into links between different kinds of rear cameras and various human visual and psychological factors, probing into users' evaluations of various rear camera visual images, is conducive to narrowing perception gap between designers and users regarding the forms rear camera, while on the other hand improving smartphone design value, and providing assistance to phone makers, designers and users. Therefore, designers should aim to satisfy users' potential psychological demands, and complement R&D engineering work, so as to render a better smartphone user experience. The existing smartphones, size proportion, colors, rear case materials and rear cameras are all factors which collectively influence users' preferences for phone appearance. Most of the products are now taking the form of full display screens, creating a uniform look and style in the front. Consequently, the emphasis of design falls to the rear camera, which is regarded as an important element of smartphone's appearance and form. From the above, it is clear that smartphones will be increasingly used and developed with amplitude in the future. A product's appearance is one of the most important factors influencing users' purchasing decisions, and different forms of products may bring different perceived values [11]. Emotion is an essential factor influencing customers' buying behavior [10].