Sidecar files for image files allow for the fining-tuning of the automatic image scaler for a particular image. The output formats and resolutions settings can all be set within the sidecar file along with the compression quality for each version of the image.
Image sidecar files follow a straightforward format for specifying the compression quality for each image version. Each format of the image also contains a dictionary of quality settings, identified by its resolution scale. For example:
avif: 1: 70 2: 50 3: 30 webp: 1: 70 2: 50 3: 30 jpeg: 1: 80 2: 40 3: 30