In this paper, we attempt to employ convolutional recurrent neural networks for weather temperature estimation using only image data. We study ambient temperature estimation based on deep neural networks in two scenarios a) estimating temperature of a single outdoor image, and b) predicting temperature of the last image in an image sequence. In the first scenario, visual features are extracted by a convolutional neural network trained on a large-scale image dataset. We demonstrate that promising performance can be obtained, and analyze how volume of training data influences performance. In the second scenario, we consider the temporal evolution of visual appearance, and construct a recurrent neural network to predict the temperature of the last image in a given image sequence. We obtain better prediction accuracy compared to the state-of-the-art models. Further, we investigate how performance varies when information is extracted from different scene regions, and when images are captured in different daytime hours. Our approach further reinforces the idea of using only visual information for cost efficient weather prediction in the future.
In addition to weather condition classification, more weather properties have also been investigated. Jacobs and his colleagues @cite_11 initiated a project for collecting outdoor scene images captured by static webcams over a long period of time. The collected images form the Archive of Many Outdoor Scene (AMOS) dataset @cite_11 . Based on the AMOS dataset, they proposed that webcams installed across the earth can be viewed as image sensors and can enable us to understand weather patterns and variations over time @cite_0 . More specifically, they adopted principal component analysis and canonical correlation analysis to predict wind velocity and vapor pressure from a sequence of images.
@cite_0 @cite_11
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We present a photometric stereo technique that operates on time-lapse sequences captured by static outdoor webcams over the course of several months. Outdoor webcams produce a large set of uncontrolled images subject to varying lighting and weather conditions. We first automatically select a suitable subset of the captured frames for further processing, reducing the dataset size by several orders of magnitude. A camera calibration step is applied to recover the camera response function, the absolute camera orientation, and to compute the light directions for each image. Finally, we describe a new photometric stereo technique for non-Lambertian scenes and unknown light source intensities to recover normal maps and spatially varying materials of the scene. Ten mood variables were related to eight weather variables in a multidimensional study. Data were collected from 24 male subjects over 11 consecutive days. The mood variables were as follows: concentration, cooperation, anxiety, potency, aggression, depression, sleepiness, scepticism, control, and optimism. The weather variables included: hours of sunshine, precipitation, temperature, wind direction, wind velocity, humidity, change in barometric pressure and absolute barometric pressure. Humidity, temperature and hours of sunshine had the greatest effect on mood. High levels of humidity lowered scores on concentration while increasing reports of sleepiness. Rising temperatures lowered anxiety and scepticism mood scores. Humidity was the most significant predictor in regression and canonical correlation analysis. Implications for school and office performance are discussed which highlight the importance of humidity as a weather variable. Images of outdoor scenes captured in bad weather suffer from poor contrast. Under bad weather conditions, the light reaching a camera is severely scattered by the atmosphere. The resulting decay in contrast varies across the scene and is exponential in the depths of scene points. Therefore, traditional space invariant image processing techniques are not sufficient to remove weather effects from images. We present a physics-based model that describes the appearances of scenes in uniform bad weather conditions. Changes in intensities of scene points under different weather conditions provide simple constraints to detect depth discontinuities in the scene and also to compute scene structure. Then, a fast algorithm to restore scene contrast is presented. In contrast to previous techniques, our weather removal algorithm does not require any a priori scene structure, distributions of scene reflectances, or detailed knowledge about the particular weather condition. All the methods described in this paper are effective under a wide range of weather conditions including haze, mist, fog, and conditions arising due to other aerosols. Further, our methods can be applied to gray scale, RGB color, multispectral and even IR images. We also extend our techniques to restore contrast of scenes with moving objects, captured using a video camera. The discovery of patterns and events in the physical world by analysis of multiple streams of sensor data can provide benefit to society in more than just surveillance applications by focusing on automated means for social scientists, anthropologists and marketing experts to detect macroscopic trends and changes in the general population. This goal complements analogous efforts in documenting trends in the digital world, such as those in social media monitoring. In this paper we show how the contents of a street webcam, processed with state-of-the-art deep networks, can provide information about patterns in clothing and their relation to weather information. In particular, we analyze a large time series of street webcam images, using a deep network trained for garment detection, and demonstrate how the garment distribution over time significantly correlates to weather and temporal patterns. Finally, we additionally provide a new and improved labelled dataset of garments for training and benchmarking purposes, reporting (58.19 , ) overall accuracy on the ACS test set, the best performance yet obtained.