Is there a way to display images in the browser without downloading them if they don't have the ContentType tag on AWS S3

'ContentType' =>'image/jpg'

I realized that this is a fix for the images that will be uploaded so i implemented it but the 100's of images already on AWS S3 server still download in the browser.

A potential solution is recursively changing the tag using the s3cmd https://serverfault.com/questions/725562/recursively-changing-the-content-type-for-files-of-a-given-extension-on-amazon-s

But i want to know if i can do this using php when i retrieve the images???