A tool that transformed a pixelated image of Barack Obama into a white man sparked a vigorous debate about racial bias in AI.

Based on the PULSE image facialiser developed by Duke University researchers, Face Depixelizer generates high resolution, de-pixelated photos from low-resolution, pixelated ones and was primarily intended to upscale pixelated portraits of characters from a number of video game franchises.

However, the tool was found to struggle consistently with non-white faces, including those of US politician and Congresswoman Alexandria-Ocasio Cortez and actress Lucy Liu.

The incident called into question the tool's reliability and prompted accusations of racism, including a heated public spat over the nature of algorithmic bias between Facebook chief AI scientist Yann LeCun.