Objective In the research on landscape history, traditional landscape paintings or geographic maps are widely used as historical materials to assist the restoration of historical sites, but there is always a mismatch between the pictorial space and the real space. This mismatch is caused by the spatial awareness and subjective goal of painters. The research on the subjectivity of painters can reveal why images selectively depict the real space and hence deduce the numerous meanings of the painted landscape.

Methods Based on the analysis of pertinent texts (such as inscriptions, travel notes, and local gazetteers), this research combines spatial analysis of architecture and image analysis methods used by art historians to analyze the visual space of images. The concept of visual space was initially proposed by art historian Wu Hong. This method considers space to be the connotation and means of visual perception, which may disclose the creative expression of three-dimensional real space in ancient China and the underlying spatial cognition. Taking the "Three Hills of Jingkou" as the research object, this research analyzes the visual space in images of the "Three Hills of Jingkou" in the middle and late Ming Dynasty to demonstrate the disparities in spatial cognition between local and non-local people. The analysis on the visual space of the aforesaid images involves the three components of viewpoint selection, composition pattern, and spatial element organization structure. The principal spatial elements include Jinshan Hill, Jiaoshan Hill, Beigu Hill, Xijin Ferry, and Zhenjiang City.

Results The "Three Hills of Jingkou" is a scenic concept that arose during the Zhengde Period of Ming Dynasty. The "three hills" refer to Jinshan Hill, Jiaoshan Hill and Beigu Hill, located near the confluence of the Grand Canal and the Yangtze River. The creators of numerous images of the "Three Hills of Jingkou" in the middle and late Ming Dynasty are mainly dominated by the two groups of local scholars and non-local tourists. By comparing the visual space in numerous images of the "Three Hills of Jingkou", the research discovers that both local and non-local painters selectively depict some of the real space, and there exist inter-group differences and intra-group convergences of the methods for "landscape-image" translation between local scholars and non-local tourists. 1) The viewpoint analysis reveals that local scholars depict the "Three Hills of Jingkou" from the perspective of Zhenjiang City, proclaiming the local attribution of the three hills; however, non-local tourists choose Xijin Ferry, a north-south traffic hub, as the vantage point for image creation. 2) The composition analysis reveals that local scholars choose the central composition to emphasize the geographical imagination centered on Beigu Hill, whereas non-local tourists choose the offset composition to guide the viewer's visual focus away from Beigu Hill to a freer state of sightseeing, and thus obtain the literati's interest in spiritual travel. 3) According to the analysis of the organizational structure of the three hills, local scholars demonstrate the real landscape order through continuous deep space, whereas non-local tourists deconstruct the existing landscape order from the image level through the multi-layer parallel structure to adapt to the visual experience of Xijin Ferry. 4) According to the analysis of the organizational structure between the hills and Zhenjiang City, local scholars emphasize the importance of the "Three Hills of Jingkou" in the city's ideal spatial order by presenting the intimate relationship between the hills and the city, whilst non-local tourists deconstruct the connection between the two by concealing the city. In conclusion, Zhenjiang scholars such as Zhang Lai integrate the three hills and strengthen their dominant position in the overall landscape of Zhenjiang Prefecture through centralized composition and the organization of the hill-city relationship, thereby making the hills the embodiment of local identity and gradually constructing a local self-review system commensurate with the rising economic and cultural status of Zhenjiang. On the other hand, non-local tourists such as Qian Gu and Bian Wenyu deconstruct the hill-city relationship by viewpoint shifting, composition alteration, and city concealment, thereby emphasizing the significance of the "Three Hills of Jingkou" as purely scenic locations to reflect their identity as tourists.

Conclusion It can be seen from various images of the "Three Hills of Jingkou" that different groups endow this local landscape with different spatial imaginations. The analysis of the visual space in the images reveals that the formation of the "Three Hills of Jingkou" is the result of a combination of local and non-local forces. The distinction between self-review and others' imagination can further convert the landscape into a field of various symbolic meanings. The exploration of visual space in images can improve the dependability of idea research by intuitively revealing the spatial cognition of different groups on the same landscape, and may serve as a methodological reference for landscape history research.