Metro Document Technologies

I have seen one drool-worthy feature which is destined for the final release of Longhorn that excites me. Coded-named 'Metro', Microsoft developed a new group of technologies designed to act as a format for electronic document portability and as a solution to many of the limitations currently presented in the world of document printing. That's not the only thing it's for, but it's the easiest way to explain it. Metro can be viewed as part competitor to the Adobe PDF standard and part replacement for Post Script, which is the document description used to tell a printer where to put elements on a page.

How can printing be exciting? Admittedly, it's not something I think about very often beyond checking to see if I have enough paper and toner. Sure printers have gotten cheaper and the liquid dyes used to add text and images to a page keep increasing in price for smaller quantities, but those aren't things to jump up and down about; especially when you're paying more to print in 8-bit color. Most printers are limited to 256 colors, which flattens out any detail you might expect to see in a really rich image. Gradients don't translate well, rich textures are lost in translation and the level of control printer hardware has over the process is very limited.

Metro fundamentally changes the way computers do printing. Color printing is extended to 16-bits per color channel, which translates to thousands of variations of those same RGB hues, with further support for 32-bit scRGB color. In the current printing world, when you print a photo on your printer, the image is translated to a format the printer understands, which eliminates some of the details. If you take RAW format images with your digital camera or the highest resolution JPEG images supported by your particular device, printing via a Metro enabled printer retains all the richness of color and subtle shading details of the image, instead of degrading the image to fit the limitations of printing. Assuming printer manufacturers issue driver updates for existing printers, all of this should function seamlessly on your current printer, without the need to throw out your current hardware for newer stuff.

Another key component in printing that makes the process painful for those of us waiting for the physical pages is spooling time. Spooling is the process of generating all the print data required to send to the printer to generate the pages. Under the current Post Script method of printing, each page is rendered in full, with no regard for repeating of elements across pages. For instance, if every page has your company logo on it and you have a 20 page document, the logo will be generated for printing 20 times. Metro rethinks this model, rendering the logo only once and tagging each page in the spool with information telling the printer where the logo needs to go, improving printing efficiency and speeding the process along.

Of course this isn't just about printing. Like PDF, Metro provides a way to package a file and send it off to people, regardless of what other software they may be running on their machine. For instance, if you have a PowerPoint presentation that needs to go to 10 other people, but you have no idea whether any of those people has PowerPoint, you won't need to compile a PowerPoint executable. Instead, you process the file with Metro and send the Metro file off to each of the 10 recipients with a reasonable amount of confidence they will be able to view the document.

The good news is, this is one feature that will trickle down to Windows XP users. I haven't found any official documentation to confirm this, but according to the Microsoft people I talked to from the Metro team, this will be a technology made compatible with Windows XP and Windows Server 2003, although if you have an older Windows operating system you may be forced to upgrade to take advantage of the features. You can read more about the Metro Specification online. Public availability of the technology is slated for "the second half of 2006," which is when Beta 2 of Longhorn will supposedly emerge.