Remco Theodorus Johannes Muijs

Coding Artifact Reduction using Non-Reference Block Grid Visibility Measure

In this work a new method is proposed for coding artifact reduction of MPEG compressed video sequences. The method makes use of a simple cost-effective technique that allows the block grid position and its visibility to be determined without the need for access to the coding parameters. This information, combined with the results of local spatial analysis of luminance and chrominance components of a decoded image, is used to effectively suppress coding artifacts while preserving the sharpness of object edges. Results of our experiments confirm the high efficiency of the proposed approach

Contrast gain and power savings using local dimming backlights

— The contrast and power consumption of todays liquid-crystal displays (LCDs) can be improved substantially by introducing (local) dimming backlights. In fact, infinite dynamic contrast and power savings of well over 50% have been claimed for such displays. Because these claims are generally made for very specific backlight designs and image content, the contrast gain and power savings are quantified as a function of the number of backlight segments for a large variety of image content.

64.2: Spatio‐temporally Consistent Video Processing for Local Backlight Dimming

Locally addressable backlights allow the contrast of LCDs to be improved while simultaneously reducing power consumption. for optimal performance, the associated video processing algorithms should prevent the backlight structure from appearing in the front-of-screen (FOS) image. We present several algorithmic developments that improve the spatio-temporal consistency of the backlight image and prevent clipping in the panel, thus substantially improving the FOS performance.

Enhancement of compressed video signals using a local blockiness metric

This paper presents a new method for enhancement of the visual quality of compressed video sequences. The algorithm detects the location of a block grid, reduces coding artifacts and enhances sharpness of image details using integrated filtering that ensures low implementation cost and high quality. The results of our experiments show the high efficiency of the proposed approach.

Motion invariant imaging by means of focal sweep

In this paper we evaluate a so-called “sweeping focus camera” of which the camera blur is insensitive to the actual distance to the objects and to the direction and magnitude of the velocities within a scene. This can be achieved by either moving the sensor linearly along the optical axis of the main lens or changing the focal length of the main lens while the shutter is open. A consistently sharp image can then be obtained by the application of a fixed inverse filter kernel, thus preventing the need for depth and motion estimation. Moreover, high frequencies are better preserved during the acquisition, such that the results achieved by inverse filtering are superior to those achievable with conventional shutter/sensor operations.