Microsoft has launched a new HD format for digital images at the PMA exhibition in Las Vegas. Its compression is said to be twice as effective as JPEG, with fewer damaging artefacts. However, the files are only half the size.

The HD Photo format, recently renamed from Windows Media Studio, is to offer higher quality images with richer colours and better colour adjustment, as well as a greater ability to preserve data. It will also be able to manipulate images in a compressed state. Microsoft hopes that HD Photo will eventually replace JPEG.

"With HD Photo, we're taking a new approach to creating and editing photos that simply isn't available to photographers with today's formats," said Amir Majidimehr, corporate vice president of the consumer media technology group at Microsoft.

"HD Photo fully preserves the original image fidelity with high dynamic range while still allowing for significant improvement in compression size," he said.

Microsoft has already developed a beta plug-in for Adobe Photoshop which will support HDRI (high dynamic range) images. The plug-in enables users to read and write HD Photo files from within Photoshop and includes support for high dynamic range pixel formats. The plug-in is compatible with both the CS3 and CS2 versions of the app, and is expected to be available within two months.

Images in HD Photo can be saved as lossless or lossy image compression; two ways of compressing images with different effects on image quality.

Microsoft said it intends to standardise the technology and will be submitting HD Photo to an "appropriate standards organisation shortly". It said the first cameras supporting HD Photo are likely to arrive in 12 to 18 months.