Radial Distortion Self-Calibration

In cameras with radial distortion, straight lines in space are in general mapped to curves in the image. Although epipolar geometry also gets distorted, there is a set of special epipolar lines that remain straight, namely those that go through the distortion center. By finding these straight epipolar lines in camera pairs we can obtain constraints on the distortion center(s) without any calibration object or plumbline assumptions in the scene. Although this holds for all radial distortion models we conceptually prove this idea using the division distortion model and the radial fundamental matrix which allow for a very simple closed form solution of the distortion center from two views (same distortion) or three views (different distortions). The non-iterative nature of our approach makes it immune to local minima and allows finding the distortion center also for cropped images or those where no good prior exists. Besides this, we give comprehensive relations between different undistortion models and discuss advantages and drawbacks.

Evaluating the Guimarães 2012 European Capital of Culture (ECOC): a Tourist Perception Approach

Guimarães has hosted, during the year of 2012, one of the European Capital of Culture (ECOC). The evaluation of the event is needed as public, private and community funds are involved. The approach considers the tourists (domestic and international) as external and independent stakeholders who assessed the cultural activities developed during the event and the attributes of the city. The results of the survey show that hosting the 2012 ECOC was a major contribution for attracting new visitors to the city, although many of them just for a short period of time. The main source of general information collected by tourists was the Internet, and the traditional media. Only a small amount of respondents demonstrated a specialized knowledge of the cultural program. The most cited and appreciated performances came from the areas of music, exhibitions, and theatre. According to the perceptions of tourists, the tangible assets were clearly detached from the set of attributes of Guimarães, including buildings, churches and chapels, whereas intangible assets were less noted. Overall, Guimarães received a very positive evaluation related to city image and stay and is highly recommended by tourists to friends and relatives.

Residents’ perception of the benefits of cultural tourism: the case of Guimarães

In many cities throughout Europe and the rest of the world, cultural tourism plays a major role in local economic development. Tourism also acts to preserve cultural heritage, as it provides a way to acquire the revenue needed to restore and preserve historical buildings, and encourages local people to value their traditions and festivals. However, tourism success can be a double-edged sword with tourist flows having a strong impact on the quality of life of residents when certain tourist thresholds are surpassed. This paper aims to address local residents’ perception of the benefits of cultural tourism. To capture their perception, a survey was implemented, addressed to both the city centre inhabitants and the non-urban residents of the Guimarães municipality.

Tourism impacts of a portuguese world heritage historic center: residents’ perspectives

The aim of this study is twofold. First, the study analyzes local community perspectives of the importance of the WHS classification of the historic center of Évora. Second, the study analyzes local residents’ perceived tourism impacts on the municipality of Évora. The methodology comprises quantitative research based on a self-administered survey applied to convenience samples of local residents of Évora in the beginning of 2014. The main results reveal that local residents have a strongly positive perception of the WHS designation. With regard to the perceived tourism impacts, a principal component factor analysis delineated three positive and three negative tourism impacts. The comparison of the mean scores of these factors across residents that live near and far from the historic center reveals that the most valued and least valued factors are common to all groups of residents. Nevertheless, in terms of positive impacts, the residents that live near the historic center revealed higher means than the residents that live far from it, whereas in terms of negative impacts, the latter group revealed higher means than former group.

Residents’ perspectives on tourism impacts of portuguese world heritage historic centers: Angra do Heroísmo and Évora

The aim of this study is twofold. First, the study analyzes local community perspectives of the importance of the World Heritage Site (WHS) classification of the historic centers of Angra do Heroísmo and Évora. Second, the study analyzes local residents’ perceived tourism impacts on the municipalities of Angra do Heroísmo and Évora. The methodology comprises quantitative research based on a self-administered survey applied to convenience samples of local residents of the two Portuguese municipalities in 2014. The main results reveal that local residents have a strongly positive perception of the WHS designation in both municipalities. With regard to the perceived tourism impacts, residents from Angra do Heroísmo have a stronger agreement about the impacts of tourism on their city than the residents of Évora, except for the negative social and cultural impacts. The comparison of the mean scores of these impacts across residents that live near and far from the historic centers reveals that the most valued and least valued impacts in the three categories of impacts (economic, social and cultural, and environmental) are common to all groups of residents. Nevertheless, residents living in or near the historic center of Angra do Heroísmo have higher means in the majority of tourism impacts (in all categories), with only one negative impact to concern the majority of respondents. Among the residents from Évora, residents living in or near the historic center have higher means in the majority of economic impacts but lower means in almost social and cultural impacts. With regard to the environmental impacts, residents living in or near the historic center have higher means scores in the positive impacts and lower means scores in the negative environmental impacts.