Google’s Lizzi Sassman and John Mueller discussed the importance of image filenames in a recent Search Off the Record podcast and at one point discussed a major mistake when it comes to filenames.
Importance of Filenames
Google’s documentation doesn’t say if image filenames are ranking factors.
But they do say that Google takes note of them in order to help figure out what the image is about.
For that reason it’s recommended by Google that images be given meaningful filenames.