SLIDE 1 Venice through the Lens of Instagram:
A Visual Narrative of Tourism in Venice
Luca Rossi1, Eric Boscaro2, Andrea Torsello2
- 1. Aston University, United Kingdom
- 2. Università Ca’ Foscari Venezia, Italy
The 8th International Workshop on Location and the Web, 24 April 2018, Lyon, France
SLIDE 2
- The tourism industry has boasted virtually uninterrupted growth over time
- International tourist arrivals have increased from 25 million globally in 1950
to 278 million in 1980, 674 million in 2000, and 1,235 million in 2016
Source: https://www.e-unwto.org/doi/pdf/10.18111/9789284419029
SLIDE 3
- Tourists make an increasing use of photo-sharing social media like
Instagram and Flickr to share their experiences online
- Geotagged data provides a rich source of information to study tourism
consumption
SLIDE 4
- The city of Venice (Italy) provides an interesting case study, being one of
the most popular destinations in one of the world most visited countries
Source: http://blog.euromonitor.com/2016/01/top-100-city-destinations-ranking-2016.html
SLIDE 5 Dataset
- We retrieve 90,000 geotagged Instagram photos
taken in Venice from Jan 2014 to Dec 2015
- We group these images into 6 categories
SLIDE 6 Dataset
- We retrieve 90,000 geotagged Instagram photos
taken in Venice from Jan 2014 to Dec 2015
- We group these images into 6 categories
Lagoon
SLIDE 7 Dataset
- We retrieve 90,000 geotagged Instagram photos
taken in Venice from Jan 2014 to Dec 2015
- We group these images into 6 categories
Townscape
SLIDE 8 Dataset
- We retrieve 90,000 geotagged Instagram photos
taken in Venice from Jan 2014 to Dec 2015
- We group these images into 6 categories
Art
SLIDE 9 Dataset
- We retrieve 90,000 geotagged Instagram photos
taken in Venice from Jan 2014 to Dec 2015
- We group these images into 6 categories
Folklore
SLIDE 10 Dataset
- We retrieve 90,000 geotagged Instagram photos
taken in Venice from Jan 2014 to Dec 2015
- We group these images into 6 categories
Food
SLIDE 11 Dataset
- We retrieve 90,000 geotagged Instagram photos
taken in Venice from Jan 2014 to Dec 2015
- We group these images into 6 categories
Other
SLIDE 12 Dataset
- We retrieve 90,000 geotagged Instagram photos
taken in Venice from Jan 2014 to Dec 2015
- We group these images into 6 categories
Lagoon Townscape Art Folklore Food Other
SLIDE 13 Image classification framework
- We create a training set of 600 manually annotated
images, 100 per class
- With this training set, we classify the remaining
images using a combination of SIFT features, BOW representations and SVM classifiers
http://www.ics.uci.edu/~majumder/VC/211HW3/vlfeat/doc/overview/sift.html
SLIDE 14 Image classification framework
- We create a training set of 600 manually annotated
images, 100 per class
- With this training set, we classify the remaining
images using a combination of SIFT features, BOW representations and SVM classifiers
http://www.ics.uci.edu/~majumder/VC/211HW3/vlfeat/doc/overview/sift.html
SLIDE 15 Image classification framework
- We create a training set of 600 manually annotated
images, 100 per class
- With this training set, we classify the remaining
images using a combination of SIFT features, BOW representations and SVM classifiers
http://vgg.fiit.stuba.sk/2015-02/bag-of-visual-words-in-opencv/
SLIDE 16 Image classification framework
- We create a training set of 600 manually annotated
images, 100 per class
- With this training set, we classify the remaining
images using a combination of SIFT features, BOW representations and SVM classifiers
- We perform 5-fold cross validation to compute the
average classification accuracy of the classifier (68%)
SLIDE 17 1st classifier: confusion matrix
Lagoon 7ownVFape Art Folklore Food VarLeV Lagoon 7ownVFape Art Folklore Food VarLeV 73 11 2 6 8 11 72 2 8 7 1 12 71 4 1 11 10 11 64 7 8 2 5 2 86 5 3 15 12 16 12 42
rate for every class except Other – Over 50% misclassification rate for this class!
SLIDE 18 1st classifier: confusion matrix
Lagoon 7ownVFape Art Folklore Food VarLeV Lagoon 7ownVFape Art Folklore Food VarLeV 73 11 2 6 8 11 72 2 8 7 1 12 71 4 1 11 10 11 64 7 8 2 5 2 86 5 3 15 12 16 12 42
issue by artificially increasing the probability of assigning an image to Other – Multiply prob of assigning to
Other by M
SLIDE 19 Lagoon 7ownVFape Art Folklore Food 9arLeV Lagoon 7ownVFape Art Folklore Food 9arLeV 68 5 1 4 2 20 9 68 1 7 15 7 65 28 8 8 55 5 24 4 77 19 9 4 2 6 79
2nd classifier: confusion matrix
through 5-fold cross- validation on the training set
found to be M=2
SLIDE 20
Misclassified photos: example
Other (wrong) Townscape (wrong)
SLIDE 21
Misclassified photos: example
Townscape (correct) Folklore (correct)
SLIDE 22 Categories distribution
Lagoon TownVFape Art FolNlore Food VarLeV 5000 10000 15000 20000 25000 30000 1umber oI ImageV 2014 2015
SLIDE 23 Categories distribution
Lagoon TownVFape Art FolNlore Food VarLeV 5000 10000 15000 20000 25000 30000 1umber oI ImageV 2014 2015
In both years, about 50% of the images are assigned to Other, for a total of 44k out of 90k images
SLIDE 24 Categories distribution
Lagoon TownVFape Art FolNlore Food VarLeV 5000 10000 15000 20000 25000 30000 1umber oI ImageV 2014 2015
25% of the photos are in the Townscape category, which comprises architectural elements such as bridges,
churches, squares, highlighting the rich architectural heritage of Venice
SLIDE 25 Number of photos taken over time
The trend is in line with the worldwide growth in Instagram active users,
which have more than doubled from the beginning of 2014 to the end of 2015
J D n F e b D r A S r D y J u n J u O A u J S e S 2 F t 1
D e F 1000 1500 2000 2500 3000 3500 1umber oI ImDJes 2014 2015
SLIDE 26 Number of photos taken over time
Peak corresponding to Carnival 2015
J D n F e b D r A S r D y J u n J u O A u J S e S 2 F t 1
D e F 1000 1500 2000 2500 3000 3500 1umber oI ImDJes 2014 2015
SLIDE 27 Frequency of Art photos in 2015
The shaded area shows the increase in the frequency of Art photos during the 56th Art Biennale
JDn Feb 0Dr ASr 0Dy Jun JuO AuJ 6eS 2Ft 1ov DeF 10 12 14 16 18 20 % oI Art ImDJes
SLIDE 28 Frequency of Art photos in 2015
Note also the slight increase during the Carnival period.
This may be due to the increased number of cultural events
- rganised in museums and galleries during that period
JDn Feb 0Dr ASr 0Dy Jun JuO AuJ 6eS 2Ft 1ov DeF 10 12 14 16 18 20 % oI Art ImDJes
SLIDE 29
Heatmap: Lagoon 2014
SLIDE 30
Heatmap: Lagoon 2015
SLIDE 31
Heatmap: Townscape 2014
SLIDE 32
Heatmap: Townscape 2015
SLIDE 33
Heatmap: Art 2014
SLIDE 34 Heatmap: Art 2014
Guggenheim Biennale Biennale
SLIDE 35
Heatmap: Art 2015
SLIDE 36 Heatmap: Art 2015
Guggenheim Biennale Biennale San Giorgio Maggiore Palazzo Grassi
SLIDE 37
Heatmap: Folklore 2014
SLIDE 38
Heatmap: Folklore 2015
SLIDE 39 Heatmap: Folklore 2015
Rialto bridge San Marco square Santa Lucia (railway station)
SLIDE 40
Heatmap: Food 2014
SLIDE 41 Heatmap: Food 2014
Al Paradiso Perduto (restaurant) Al Timon Bragozzo (restaurant) Tonolo (pastry shop)
SLIDE 42
Heatmap: Food 2015
SLIDE 43
Heatmap: February 2015 (during Carnival)
SLIDE 44
Heatmap: March 2015 (after Carnival)
SLIDE 45 SDntD CroFe SDn 0DrFo CDstello Dorsoduro SDn Polo CDnnDregio 5 10 15 20 25 % oI Folklore IPDges During CDrnivDl AIter CDrnivDl
During Carnival After Carnival
SLIDE 46 SDntD CroFe SDn 0DrFo CDstello Dorsoduro SDn Polo CDnnDregio 5 10 15 20 25 % oI Folklore IPDges During CDrnivDl AIter CDrnivDl
During Carnival After Carnival
SLIDE 47
- 1. Study limited to users of Instagram
- 2. Image classification not state-of-the-art
- 3. Large number of photos classified as Other
- 4. Textual information (e.g, #hashtags) discarded
SLIDE 48 Conclusion and future work
- We explored tourism consumption through the lens
- f Instagram
- The analysis of 90k photos over two years highlights
the presence of touristic hotspots
- The signal is influenced by external events and can
reveal preferred touristic routes during such events
SLIDE 49 Conclusion and future work
- Potential areas of applications:
– Urban planning – Marketing and advertising campaigns – Personalised tourist guide by linking city representation to user preferences, as determined by his/her shared photos
- Future work will investigate text to associate
sentiment to places and will use CNN to improve image classification
SLIDE 50 Questions?
https://cs.aston.ac.uk/~rossil/ l.rossi@aston.ac.uk blextar
The 8th International Workshop on Location and the Web, 24 April 2018, Lyon, France