Colour displays for categorical images

We propose a method for identifying a set of colours for displaying 2-D and 3-D categorical images when the categories are unordered labels. The principle is to find maximally distinct sets of colours. We either generate colours sequentially, to maximise the dissimilarity or distance between a new colour and the set of colours already chosen, or use a simulated annealing algorithm to find a set of colours of specified size. In both cases, we use a Euclidean metric on the perceptual colour space, CIE-LAB, to specify distances

Die Rolle des Corporate Foresight im Innovationsprozess: Ziele, Ausgestaltung und Erfahrungen am Beispiel der Siemens AG

This article focuses on activities of corporate foresight that constitute one of the core elements of strategic innovation management. Hence, corporate foresight plays a crucial role for the mid- to longterm competitiveness of firms. It typically comprises the stages of idea generation to idea selection. Forecasting activities are of particular importance to corporate foresight as they allow detecting future trends and discontinuities such as technology shocks. Though there is much theoretical knowledge on corporate foresight activities, there is only little empirical evidence that shows how these activities are actually conducted in practice. Using the example of the Siemens AG, this article reveals how corporate foresight is professionally implemented in this company, which goals are pursued with it and what kind of experiences have been made so far. In particular, the motivation of all employees who are engaged in this process and the general acceptance of the foresight process have been key to its success

G-CSF Prevents the Progression of Structural Disintegration of White Matter Tracts in Amyotrophic Lateral Sclerosis: A Pilot Trial

Background: The hematopoietic protein Granulocyte-colony stimulating factor (G-CSF) has neuroprotective and regenerative properties. The G-CSF receptor is expressed by motoneurons, and G-CSF protects cultured motoneuronal cells from apoptosis. It therefore appears as an attractive and feasible drug candidate for the treatment of amyotrophic lateral sclerosis (ALS). The current pilot study was performed to determine whether treatment with G-CSF in ALS patients is feasible.Methods: Ten patients with definite ALS were entered into a double-blind, placebo-controlled, randomized trial. Patients received either 10 mu g/kg BW G-CSF or placebo subcutaneously for the first 10 days and from day 20 to 25 of the study. Clinical outcome was assessed by changes in the ALS functional rating scale (ALSFRS), a comprehensive neuropsychological test battery, and by examining hand activities of daily living over the course of the study (100 days). The total number of adverse events (AE) and treatment-related AEs, discontinuation due to treatment-related AEs, laboratory parameters including leukocyte, erythrocyte, and platelet count, as well as vital signs were examined as safety endpoints. Furthermore, we explored potential effects of G-CSF on structural cerebral abnormalities on the basis of voxel-wise statistics of Diffusion Tensor Imaging (DTI), brain volumetry, and voxel-based morphometry.Results: Treatment was well-tolerated. No significant differences were found between groups in clinical tests and brain volumetry from baseline to day 100. However, DTI analysis revealed significant reductions of fractional anisotropy (FA) encompassing diffuse areas of the brain when patients were compared to controls. On longitudinal analysis, the placebo group showed significant greater and more widespread decline in FA than the ALS patients treated with G-CSF.Conclusions: Subcutaneous G-CSF treatment in ALS patients appears as feasible approach. Although exploratory analysis of clinical data showed no significant effect, DTI measurements suggest that the widespread and progressive microstructural neural damage in ALS can be modulated by G-CSF treatment. These findings may carry significant implications for further clinical trials on ALS using growth factors

Visually optimized image display using a small customizable color palette

Currently, many low cost computer monitors can only simultaneously display a palette of 256 colors. However, this palette is usually selectable from a very large gamut of available colors. For many applications involving natural color images, this limited palette size imposes a significant constraint on the achievable image quality. Error diffusion is a powerful method to improve the subjective quality of a displayed image, when only a small set of colors is available. In this work, we propose the design of a visually optimized error diffusion filter for monochrome and color image display applications. As a result, the displayed images contain errors mostly at high spatial frequencies, which are less noticeable to the viewer. We also examine the design of a universal and an image dependent color palette for use with halftoning methods such as error diffusion. The advantage of a universal color palette is that it is fixed and therefore allows multiple images to be displayed simultaneously. Our palette is designed by employing a new vector quantization method known as sequential scalar quantization (SSQ) to allocate the colors in a visually uniform color space. This SSQ method achieves near optimal allocation, but may be efficiently implemented using a series of look up tables. Finally, we investigate a visually weighted mean squared error measure to compare the performance of our optimized algorithm to standard error diffusion. Our metric is based on the color difference in CIEL*a*b*, but also accounts for the lowpass characteristic of human contrast sensitivity

Optimized Error Diffusion for High Quality Image Display

Displaying natural images on an 8 bit computer monitor requires a substantial reduction of physically distinct colors. Simple minimum mean squared error (MMSE) quantization with 8 levels of red and green and 4 levels of blue yields poor image quality. A powerful means to improve the subjective quality of a quantized image is error diffusion. Error diffusion works by shaping the spectrum of the display error. Considering an image in raster ordering, this is done by adding a weighted sum of previous quantization errors to the current pixel before quantization. These weights form an error diffusion filter. We propose a method to find visually optimized error diffusion filters for monochrome and color image display applications. The design is based on the lowpass characteristic of the contrast sensitivity of the human visual system. The filter is chosen so that a cascade of the quantization system and the observer's visual modulation transfer function yields a whitened error spectrum. The resu..