de G Gerard Haan

An Overview and Performance Evaluation of Classification-Based Least Squares Trained Filters

An overview of the classification-based least squares trained filters on picture quality improvement algorithms is presented. For each algorithm, the training process is unique and individually selected classification methods are proposed. Objective evaluation is carried out to single out the optimal classification method for each application. To optimize combined video processing algorithms, integrated solutions are benchmarked against cascaded filters. The results show that the performance of integrated designs is superior to that of cascaded filters when the combined applications have conflicting demands in the frequency spectrum.

An efficient true-motion estimator using candidate vectors from a parametric motion model

Some efficient motion estimation algorithms select their output motion vector from a limited number of likely correct candidate, or prediction, vectors. In this paper, next to the known spatial and temporal prediction vectors, an additional and independent prediction is proposed. This candidate is generated with a parametric model describing the global motion in a previously estimated motion vector field. The proposal is elaborated as an addition to the three-dimensional (3-D) recursive search block-matching algorithm. The evaluation shows that a subpixel accurate, true-motion estimator results with a very low operations count.

Efficient nucleus detector in histopathology images

In traditional cancer diagnosis, (histo)pathological images of biopsy samples are visually analysed by pathologists. However, this judgment is subjective and leads to variability among pathologists. Digital scanners may enable automated objective assessment, improved quality and reduced throughput time. Nucleus detection is seen as the corner stone for a range of applications in automated assessment of (histo)pathological images.

Progress in motion estimation for consumer video format conversion

Two generations of application specific ICs for motion compensated consumer video format conversion (MC-VFC) are available, and real time DSP software for MC-VFC has been demonstrated. The breakthroughs enabling this progress have come from motion estimation. The paper gives an overview of the progress achieved in motion estimation for consumer electronics applications.

An overview of flaws in emerging television displays and remedial video processing

New display principles aim at supreme image quality. The temporal aspects of these devices sometimes remain underexposed in the literature, and the paper presents an overview of new artifacts and possible remedies with signal processing. We discuss typical artifacts due to the unfavourable properties of emerging television displays. We introduce a processing model that eliminates or at least reduces the various artifacts that result from temporal imperfections of CRTs with alternative scanning, liquid crystal displays (LCDs), tiled displays, plasma display panels (PDPs), and colour sequential displays. We conclude that knowledge of the motion in the scene, i.e. motion estimation, is essential to at least partially repair the often unfavourable temporal behaviour of these displays. Such repair is realistic, as these displays have appeared on the market at the moment motion vector estimation has come to maturity for consumer applications.

Making the best of legacy video on modern displays

— The recent revolution in display technology enables bright high-resolution displays, thereby removing one of the bottlenecks in video quality. How to profit from HD flat-panel displays when watching legacy SD-video material will be discussed. An overview of resolution up-conversion techniques will be presented, including an objective (MSE-scores) and a subjective assessment. Screenshots are also included to illustrate the quality of the algorithms.

Television Display Processing: Past & Future

The first quarter century of the ICCE brought us motion-compensated de-interlacing & picture-rate conversion, resolution up-conversion, flat panel displays and HDTV. The paper gives an overview and points at new challenges for signal processing, broadcast formats and display technologies.

Memory-Centric Video Processing

This work presents a domain-specific memory subsystem based on a two-level memory hierarchy. It targets the application domain of video post-processing applications including video enhancement and format conversion. These applications are based on motion compensation and/or broad class of content adaptive filtering to provide the highest quality of pictures. Our approach meets the required performance and has sufficient flexibility for the application domain. It especially aims at the implementation-wise most challenging applications: compute-intensive and bandwidth-demanding applications that provide the highest quality at high picture resolutions. The lowest level of the memory hierarchy, closest to the processing element, the L0 scratchpad, is organized specifically to enable fast retrieval of an arbitrarily positioned 2-D block of pixels to the processing element. To guarantee the performance, most of its addressing logic is hardwired, leaving a user a set of API for initialization and storing/loading the data to/from the L0 scratchpad. The next level of the memory hierarchy, the L1 scratchpad, minimizes the off-chip memory bandwidth requirements. The L1 scratchpad is organized specifically to enable efficient aligned block-based accesses. With lower data rates compared to the L0 scratchpad and aligned block access, software-based addressing is used to enable full flexibility. The two-level memory hierarchy exploits prefetching to further improve the performance.

Optimization of Hierarchical 3DRS Motion Estimators for Picture Rate Conversion

There is a continuous pressure to lower the implementation complexity and improve the quality of motion-compensated picture rate conversion methods. Since the concept of hierarchy can be advantageously applied to many motion estimation methods, we have extended and improved the current state-of-the-art motion estimation method in this field, 3-D Recursive Search (3DRS), with this concept. We have explored the extensive parameter space and present an analysis of the importance and influence of the various parameters for the application of picture rate conversion. Since well-performing motion estimation methods for picture rate conversion show a tradeoff between prediction accuracy and spatial motion field consistency, determining the optimal tradeoff is an important part of the analysis. We found that the proposed motion estimators are superior to multiple existing techniques as well as standard 3DRS with regard to performance at a low computational complexity.

Real-time recursive motion segmentation of video data on a programmable device

We previously reported on a recursive algorithm enabling real-time object-based motion estimation (OME) of standard definition video on a digital signal processor (DSP). The algorithm approximates the motion of the objects in the image with parametric motion models and creates a segmentation mask by assigning to every block in the image the best matching model. It was found that the calculation of the segmentation mask was most critical for both the real-time behaviour and the quality of the motion vector field. This publication details the motion segmentation module and discusses a number of options which improve the quality/complexity ratio of the motion segmentation.