Fevr comes with a unique, built-in image optimizer. You can losslessly compress your JPEG and PNG images, and improve your site’s performance. This feature will be available only if you activated your copy.
You can optimize all of your images in Media > Image Optimizer
You can enable Image Optimization in Theme Settings > Performance to optimize images on the fly during the upload process.
You can optimize individually images on the attachment single view on backend as well: Media > Library > Pick an image. Find the Optimize Image button on the bottom of the image properties.