Intel Continues Readying Linux For Lunar Lake's New Adaptive Sharpening Filter

Back in February I wrote about Intel's open-source graphics driver engineers working on a new adaptive sharpening filter capability to be found with upcoming Xe2 graphics starting with Lunar Lake. This new adaptive sharpening filter has minimal power and performance impact and at least according to the driver engineers is working out rather well. Besides the Intel Xe kernel driver support around enabling this adaptive sharpening filter, Intel has also been readying the rest of the Linux desktop stack for exposing this capability.

Sent out this morning were the newest patches for exposing this capability via a DRM sharpening property. Exposing this as a new Direct Rendering Manager property could potentially allow other vendors/drivers to similarly expose any sharpening capabilities in a uniform manner as well to user-space.

The cover letter of the DRM sharpening property sums up the Xe2 display feature and overall focus of this new property as:

"Many a times images are blurred or upscaled content is also not as crisp as original rendered image. Traditional sharpening techniques often apply a uniform level of enhancement across entire image, which sometimes result in over-sharpening of some areas and potential loss of natural details.

Intel has come up with Display Engine based adaptive sharpening filter with minimal power and performance impact. From LNL onwards, the Display hardware can use one of the pipe scaler for adaptive sharpness filter. This can be used for both gaming and non-gaming use cases like photos, image viewing. It works on a region of pixels depending on the tap size.

This is an attempt to introduce an adaptive sharpness solution which helps in improving the image quality. For this new CRTC property is added. The user can set this property with desired sharpness strength value with 0-255. A value of 1 representing minimum sharpening strength and 255 representing maximum sharpness strength. A strength value of 0 means no sharpening or sharpening feature disabled. It works on a region of pixels depending on the tap size. The coefficients are used to generate an alpha value which is used to blend the sharpened image to original image."

Separately are patches pending for GNOME's Mutter compositor for supporting use of this adaptive sharpening property. Ultimately the plan is to expose this adaptive sharpening option via a UI slider but for now can be manipulated from the command-line.

Intel engineer Adarsh G M provided a few screenshots in that Mutter merge request of the feature in action under GNOME with presumably a Lunar Lake laptop as the test platform.

The Lunar Lake Linux support overall appears to be in good standing already with the latest open-source bits but it is around the Xe2 integrated graphics that a lot of work remains flying around and at the moment is still disabled by default (hidden behind the Xe driver's force probe parameter). We'll see how the Xe2 graphics are by the time Lunar Lake laptops begin shipping later this quarter and I intend to buy one on launch day to provide for Linux testing of this exciting Intel SoC.