Speaker estimation method and speaker estimation device

A speaker estimation device that estimates a speaker from audio and image, comprising:

• a processor including a memory and a control component;
• a microphone that receives audio;
• and
• a camera that receives an image of respective persons, the image not taken during speaking by the respective persons,
• the processor configured to perform:
• an image input controller function to control a position and an angle for inputting the image of the camera;
• and
• a control function to control the microphone, the camera, and the image input controller function,
• wherein the processor performs the control function to:
• extract a feature quantity comprising a first vector representing a voice characteristic from the audio input from the microphone;
• detect person regions of the respective persons from the image input from the camera;
• estimate a feature quantity comprising a second vector representing a voice characteristic from the respective detected person regions;
• control the image input controller function to perform a change such that an image taken from another position and with another angle is input when any person is not detected;
• calculate a similarity between the feature quantity representing the voice characteristic extracted from the input audio and the feature quantity representing the voice characteristic estimated from the person region in the image by comparing at least an L2 norm between the first vector and the second vector;
• and
• estimate a speaker from the calculated similarity.