Images and Google approach

Hi Everyone,

We are redesigning our company's website. Yesterday we had a meeting about the images, which we will add to it. And two questions popped up during the meeting. I tried to find answers online, but they were not entirely satisfying for me.

1. What's google approach to image quality - does a low quality may affect SEO? I know it may affect the UX. I found two different approaches on google websites:
   a.
   High-quality photos appeal to users more than blurry, unclear images. Also, sharp images are more appealing to users in the result thumbnail and increase the likelihood of getting traffic from users.
   b.
   Experiment with optimal quality settings for raster formats: don’t be afraid to dial down the “quality” settings, the results are often very good and byte savings are significant.
2. Should we add density descriptors to the images and upload them in three different resolutions - Mobile, Web and Retina?