Jointly Resampling and Reconstructing Corrupted Images for Image Classification using Frequency-Selective Mesh-to-Grid Resampling

Neural networks became the standard technique for image classification throughout the last years. They are extracting image features from a large number of images in a training phase. In a following test phase, the network is applied to the problem it was trained for and its performance is measured. In this paper, we focus on image classification. The amount of visual data that is interpreted by neural networks grows with the increasing usage of neural networks. Mostly, the visual data is transmitted from the application side to a central server where the interpretation is conducted. If the transmission is disturbed, losses occur in the transmitted images. These losses have to be reconstructed using postprocessing. In this paper, we incorporate the widely applied bilinear and bicubic interpolation and the high-quality reconstruction Frequency-Selective Reconstruction (FSR) for the reconstruction of corrupted images. However, we propose to use Frequency-Selective Mesh-to-Grid Resampling (FSMR) for the joint reconstruction and resizing of corrupted images. The performance in terms of classification accuracy of EfficientNetB0, DenseNet121, DenseNet201, ResNet50 and ResNet152 is examined. Results show that the reconstruction with FSMR leads to the highest classification accuracy for most networks. Average improvements of up to 6.7 percentage points are possible for DenseNet121.Comment: IEEE 24th International Workshop on Multimedia Signal Processing 202

Frequency-Selective Geometry Upsampling of Point Clouds

The demand for high-resolution point clouds has increased throughout the last years. However, capturing high-resolution point clouds is expensive and thus, frequently replaced by upsampling of low-resolution data. Most state-of-the-art methods are either restricted to a rastered grid, incorporate normal vectors, or are trained for a single use case. We propose to use the frequency selectivity principle, where a frequency model is estimated locally that approximates the surface of the point cloud. Then, additional points are inserted into the approximated surface. Our novel frequency-selective geometry upsampling shows superior results in terms of subjective as well as objective quality compared to state-of-the-art methods for scaling factors of 2 and 4. On average, our proposed method shows a 4.4 times smaller point-to-point error than the second best state-of-the-art PU-Net for a scale factor of 4.Comment: 5 pages, 3 figures, International Conference on Image Processing (ICIP) 202

Formangepasste diskrete Cosinus-Transformation für die Prädiktionsverbesserung im HEVC

Um die Kompression in der Videocodierung zu verbessern, führen wir eine explizite Referenzbildentrauschung in die Codierschleife eines Videocodecs ein. Motiviert durch den Gedanken, dass die Leistung des Prädiktionsfehlers höher sein kann, falls Rauschen in dem zu codierenden Video vorhanden ist, wird die Bewegungskompensation durch die eingeführten Module verbessert. Es wird gezeigt wie man einen solchen Ansatz für die Codierung bei sehr kleinen Einstellungen des Quantisierungsparameters aber auch bei sehr groben Quantisierungseinstellungen verwenden kann. Die entwickelten Algorithmen wurden in der Referenzsoftware des aktuellen HEVC-Standards getestet. Die Simulationsergebnisse zeigen, dass mit der vorgeschlagenen Vorgehensweise maximale Bitratenersparnisse von bis zu 10 % für niedrige als auch hohe Quantisierungsparametereinstellungen erreicht werden können. Im Durchschnitt wurden Bitratenersparnisse von 7 % für hohe Qualität und 5 % für niedrige Qualität bei Codierung der ClassB-Sequenzen erreicht

An Endogenously Derived AK-model of Economic Growth

Assuming a production process with returns to scale that vary with the intensity it is operated at, an AK-model of endogenous growth with constant returns to scale in production is shown to arise due to replication driven by profit-maximization. If replication occurs at the efficiency-maximizing scale, the result applies also when the number of production processes must be discrete, thus overcoming the so-called integer problem. When competition is imperfect, there is only convergence toward the AK-model for large enough input use, so an economy is more prone to stalling in a steady-state without growth, the smaller and less competitive it is. Inefficient scaling also raises the risk of stalling

Improving HEVC Encoding of Rendered Video Data Using True Motion Information

This paper shows that motion vectors representing the true motion of an object in a scene can be exploited to improve the encoding process of computer generated video sequences. Therefore, a set of sequences is presented for which the true motion vectors of the corresponding objects were generated on a per-pixel basis during the rendering process. In addition to conventional motion estimation methods, it is proposed to exploit the computer generated motion vectors to enhance the ratedistortion performance. To this end, a motion vector mapping method including disocclusion handling is presented. It is shown that mean rate savings of 3.78% can be achieved.Comment: 4 pages, 4 figure

Recommendation for post-exposure prophylaxis after potential exposure to herpes b virus in Germany

Although the risk of a herpes B virus (Cercopithecine herpes virus 1) infection is low, the clinical course of the infectious disease is generally unfavourable. A high safety standard can be achieved if people with professional contact to primates apply proper organisational, technical and personal safety precautions. The risk can be considerably reduced if animal keepers, laboratory assistants and scientists receive adequate information about the pathology of herpes B virus and are well trained in the necessary procedures and the precautions. For this reason, comprehensive and regular training, information and instruction must be provided to all primate workers and to laboratory workers who come into contact with potentially infectious material. After potential contamination, the risk for the affected worker must be assessed immediately and post-exposure chemoprophylaxis performed if necessary. This necessitates internal risk assessment. An interdisciplinary group of experts has developed an action plan for Germany