We must compress sended image before we saved them to prevent overusage of the disk. Maybe this can be achieve with [imagemin](https://github.com/imagemin/imagemin#readme) or with [jimp](https://github.com/oliver-moran/jimp#readme) (by scaling down the image) https://github.com/MediaComem/modos/blob/b40aa3bb86e991d656e2173efc39456bc2a5e332/packages/backend/src/entity/Observation.ts#L48
