Blu-ray Disc (BD or Blu-ray) is a high-definition home entertainment format on the standard 120mm optical discs. Launched in 2006, it competed briefly, but fiercely from 2006 to 2008 with HD DVD before becoming the standardized high-definition home entertainment format.
Blu-ray releases, much like DVDs, are divided into separate regions to restrict the areas specific discs can be played. The following is a guide to the regions and which areas of the world they relate to:
"Region free" releases.
East Asia (except Mainland China and Mongolia), Southeast Asia, the Americas, and their dependencies.
Africa, Southwest Asia, Europe (except Russia, Ukraine, and Belarus), Oceania, and their dependencies (except French Guiana).
Central Asia, East Asia (Mainland China and Mongolia only), South Asia, central Eurasia, and their dependencies.
CBS have commented that a Star Trek: Deep Space Nine Blu-ray release is a possibility. In a post on Twitter, Michael Okuda commented "We've heard that CBS execs would love to give DS9 the HD treatment, if sales for TNG HD continue to support it". Craig Weiss of CBS Digital commented that there has been talk about remastering Star Trek: Deep Space Nine,  but as of December 2014, there had been no official decision made public.
Roger Lay, Jr. commented regarding DS9 on Blu-ray: ""We're all ready to go, man. I've been finding some really cool stuff related to the making of Deep Space Nine that I can’t wait to put on a Blu-ray set". Lay. Jr. also commented: "Deep Space Nine, we all want to do it. I’ll tell you that. I think it’ll be more difficult in the sense that by season 4 of DS9 you had digital elements, a lot of digital elements. By the Dominion War they were doing entire sequences that were digital, there were no models anymore. On TNG we've had all these plates and all these model motion-control shots to re-composite. You don't have anything like that now. So you kind of have to recreate everything when it comes to that stage. I think the first three seasons will be fairly close to what has been done on Next Gen, but by season 4 and beyond it will get a lot more complicated. So all of that has to be factored in. And honestly they have to look at the sales of Next Gen and see how it did overall and what kind of a budget they could allot for Deep Space Nine. So will it happen immediately? I don’t know. Do we all want to go and bring Deep Space Nine back? Absolutely. I think the next couple of months will be crucial. It will also be crucial to fans who have been waiting for all seven seasons of TNG to be released. It sounds sad, but it’s a business decision when it should be a creative one. But you need sales in order to put out more product, it’s as simple as that. We’re hoping to get news within the next several months. But if fans want to do anything to make that happen, pick up these Blu-ray sets right now, because the entire Next Generation collection will be out." 
Star Trek: The Next Generation - Season 3, The Best of Both Worlds, Star Trek: The Motion Picture, Star Trek III: The Search for Spock, Star Trek V: The Final Frontier, Star Trek Generations, Star Trek: Insurrection, Star Trek Nemesis