Apple might be grabbing all the headlines for its Retina display technology this week, but Microsoft wants to remind the world that its OEMs are building post-HD resolutions for upcoming Windows 8 tablets. In a Building Windows 8 blog post today, the company is talking device diversity and pixel densities.

Dots per inch (DPI) adjustments in Windows have always been hit and miss, mainly due to desktop apps not being built to scale properly — resulting in small user interface elements on higher DPI screens. Microsoft is tackling this problem with its new Metro style applications. Developers will be able to target three pixel density "sweet spots" for scaling graphics and visuals within apps. Although Apple's latest iPad adopts a scale factor of 200 percent (due to the higher pixel density), Microsoft is proposing three scale percentages in Windows 8: no scaling at 100%, 140% for HD tablets, 180% for quad-XGA tablets. Developers can use vector graphics or CSS3 to load images at different scales.

Microsoft's scaling levels will help apps look near-identical across varied screen resolutions and sizes. The company will support a minimum screen resolution of 1024x768, so that developers can create richer apps that scale up. Windows 8 users with resolutions lower than 1366x768 will not be able to take advantage of the app snap feature though, Microsoft needs the extra 320px of width to snap an application and ensure the primary Metro app still uses a 1024x768 resolution. There is no maximum Windows 8 resolution, but Microsoft is urging developers to consider larger screens to ensure Metro style apps make use of the space efficiently. With all the talk of Metro style apps, Microsoft hasn't detailed any resolution scaling improvements for the desktop mode in Windows 8. The Consumer Preview version is largely untouched from Windows 7, so it appears that most of the scaling and touch friendly improvements are designed for Microsoft's Metro world.