Crowdsourcing as an Analytical Method: Metrology of Smartphone Measurements in Heritage Science

Abstract

This researcha ssesses the precision, repeatability, and accuracy of crowdsourced scientific measurements,a nd whether their quality is sufficient to provide usable results. Measurements of colour and area were chosen because of the possibility of producing them with smartphone cameras.T he quality of the measurements was estimated experimentally by comparing data contributed by anonymous participants in heritage sites with reference measurements of knownaccuracy and precision. Participants performed the measurements by taking photographs with their smartphones,from whichcolour and dimensional data could be extracted. The results indicate that smartphone measurements provided by citizen scientists can be used to measure changes in colour,b ut that the performance is strongly dependent on the measured colour coordinate.T he same method can be used to measure areas when the difference in colour with the neighbouring areas is large enough. These results render the method useful in some heritage science contexts,b ut higher precision would be desirable.

An Adaptive Colour Calibration for Crowdsourced Images in Heritage Preservation Science

“…Mainly, the considered research works employ crowdsourced data from cellphones of third-party users as supply for the control task [10] [30]. There, they assess that taking pictures of the visitors to a heritage piece and extracting colorimetric information after performing some needed preprocesses is a satisfactory manner of evaluating the status of a monitored object, while being a non-invasive approach at the same time [20].…”

“…Effectively and taking this into account, in this paper we propose an alternative to the works described in [10] and [30]. It also acts as a starting point where further research and improvement based on more refined mathematical processes can take place with ease in a near future.…”

“…In a similar context to [20], the ending color coordinates of the material tags in CIELAB are then extracted as a means of obtaining their chromatic information. We base the evaluation of the quality of our results on the measures of recent works of analogous approach like [10] and [21], and our results show that our approach improves the stability and quality of the information for future real applications. Effectively, our proposal is thus suitable for recognizing colour changes on matter, and thus its degradation, alongside time and judging the necessity of maintenance of the piece in question in a non-invasive way.…”

“…Hereby, this paper aims to expose an improving focus on image processing to adapt crowdsourced information for cultural heritage maintenance in controlled environments. Previously published papers practiced photography processes without any further operation, or a simple white balancing, and they threw a study on the variability and stability of the information between images of different cameras by taking difference and tolerance measures [10] of the CIELAB colour coordinates of the pieces under observation. CIELAB is widely employed as an accurate colour specification space in heritage science [19] [14].…”

Using Citizen Heritage Science to monitor remote sites; a comparison of two methods

“…Smartphone cameras are capable of monitoring a variety of issues in heritage such as biological growth, erosion and one-off events such as vandalism [17][18][19][20]. The vast majority of scheduled monuments across the UK are small, unstaffed and not often visited by heritage professionals but are often destinations for tourists and popular walking sites for locals.…”