Image size + resolution for Journey banner?

Summary:

From client: "We need a way to upload quality image for Journey page. As per the requirement, we have two different images for Journey tile and the banner once you click on the tile. Due to this, we are using URL but this is reducing the quality and the image in the banner looks blurry. "

Content (required):

We tried two different sizes: 1238x275 and 570x104

Version (include the version you are using, if applicable):

23A

Code Snippet (add any code snippets that support your topic, if applicable):