Crowdsourcing Subjective Image Quality Evaluation

Flavio Ribeiro, Dinei Florencio, and Vitor Nascimento


Subjective tests are generally regarded as the most reliable and definitive

methods for assessing image quality. Nevertheless, laboratory

studies are time consuming and expensive. Thus, researchers often

choose to run informal studies or use objective quality measures,

producing results which may not correlate well with human perception.

In this paper we propose a cost-effective and convenient subjective

quality measure called crowdMOS, obtained by having internet

workers participate in MOS (mean opinion score) subjective

quality studies. Since these workers cannot be supervised, we propose

methods for detecting and discarding inaccurate or malicious

scores. To facilitate this process, we offer an open source set of tools

for Amazon Mechanical Turk, which is an internet marketplace for

crowdsourcing. These tools completely automate the test design,

score retrieval and statistical analysis, abstracting away the technical

details of Mechanical Turk and ensuring a user-friendly, affordable

and consistent test methodology. We demonstrate crowdMOS using

data from the LIVE subjective quality image dataset, showing that it

delivers accurate and repeatable results.


Publication typeInproceedings
Published inICIP
PublisherIEEE SPS
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