https://phys.org/news/2018-10-mixedemotions-open-source-toolbox-emotion-analysis.html

Our actions are affected by both our mood and the way we perceive others. There is a growing demand for automatic analysis of emotions in different fields. The possible applications are wide, including call centers, smart environments, brand reputation analysis and assistive technology.

First, analysis tools can be highly complex. Emotion detection may require age, gender or facial recognition. Second, the analysis also requires both prior knowledge and linguistic resources that are not always public, and third, these tools are usually designed in one language, generally in English.