The IPTC Photo Metadata Standard is the most widely used standard to describe photos. It consists of two schemas – IPTC Core and IPTC Extension.| IPTC
About the Standard| www.iptc.org
The Google Search Essentials make up the core parts of what makes your web-based content (web pages, images, videos, or other publicly-available material that Google finds on the web) eligible to appear and perform well on Google Search.| Google for Developers
Schema.org Type: ImageObject - An image file.| schema.org
Follow our general guidelines for structured data. These guidelines will help your structured data be eligible for rich Google Search results.| Google for Developers
Google uses structured data markup to understand content. Explore this guide to discover how structured data works, review formats, and learn where to place it on your site.| Google for Developers
Google supports several sitemap formats. Follow this guide to learn about formats, how to build a sitemap, and how to submit a sitemap to Google.| Google for Developers
Google Search helps users visually discover information on the web. Explore image SEO best practices such as image captions and badges.| Google for Developers