654 research outputs found
Image fusion techniqes for remote sensing applications
Image fusion refers to the acquisition, processing and synergistic combination of information provided by various sensors or by the same sensor in many measuring contexts. The aim of this survey paper is to describe three typical applications of data fusion in remote sensing. The first study case considers the problem of the Synthetic Aperture Radar (SAR) Interferometry, where a pair of antennas are used to obtain an elevation map of the observed scene; the second one refers to the fusion of multisensor and multitemporal (Landsat Thematic Mapper and SAR) images of the same site acquired at different times, by using neural networks; the third one presents a processor to fuse multifrequency, multipolarization and mutiresolution SAR images, based on wavelet transform and multiscale Kalman filter. Each study case presents also results achieved by the proposed techniques applied to real data
Automated High-resolution Earth Observation Image Interpretation: Outcome of the 2020 Gaofen Challenge
In this article, we introduce the 2020 Gaofen Challenge and relevant scientific outcomes. The 2020 Gaofen Challenge is an international competition, which is organized by the China High-Resolution Earth Observation Conference Committee and the Aerospace Information Research Institute, Chinese Academy of Sciences and technically cosponsored by the IEEE Geoscience and Remote Sensing Society and the International Society for Photogrammetry and Remote Sensing. It aims at promoting the academic development of automated high-resolution earth observation image interpretation. Six independent tracks have been organized in this challenge, which cover the challenging problems in the field of object detection and semantic segmentation. With the development of convolutional neural networks, deep-learning-based methods have achieved good performance on image interpretation. In this article, we report the details and the best-performing methods presented so far in the scope of this challenge
CAD-Net: A Context-Aware Detection Network for Objects in Remote Sensing Imagery
Accurate and robust detection of multi-class objects in optical remote
sensing images is essential to many real-world applications such as urban
planning, traffic control, searching and rescuing, etc. However,
state-of-the-art object detection techniques designed for images captured using
ground-level sensors usually experience a sharp performance drop when directly
applied to remote sensing images, largely due to the object appearance
differences in remote sensing images in term of sparse texture, low contrast,
arbitrary orientations, large scale variations, etc. This paper presents a
novel object detection network (CAD-Net) that exploits attention-modulated
features as well as global and local contexts to address the new challenges in
detecting objects from remote sensing images. The proposed CAD-Net learns
global and local contexts of objects by capturing their correlations with the
global scene (at scene-level) and the local neighboring objects or features (at
object-level), respectively. In addition, it designs a spatial-and-scale-aware
attention module that guides the network to focus on more informative regions
and features as well as more appropriate feature scales. Experiments over two
publicly available object detection datasets for remote sensing images
demonstrate that the proposed CAD-Net achieves superior detection performance.
The implementation codes will be made publicly available for facilitating
future researches
Remote Sensing Object Detection Meets Deep Learning: A Meta-review of Challenges and Advances
Remote sensing object detection (RSOD), one of the most fundamental and
challenging tasks in the remote sensing field, has received longstanding
attention. In recent years, deep learning techniques have demonstrated robust
feature representation capabilities and led to a big leap in the development of
RSOD techniques. In this era of rapid technical evolution, this review aims to
present a comprehensive review of the recent achievements in deep learning
based RSOD methods. More than 300 papers are covered in this review. We
identify five main challenges in RSOD, including multi-scale object detection,
rotated object detection, weak object detection, tiny object detection, and
object detection with limited supervision, and systematically review the
corresponding methods developed in a hierarchical division manner. We also
review the widely used benchmark datasets and evaluation metrics within the
field of RSOD, as well as the application scenarios for RSOD. Future research
directions are provided for further promoting the research in RSOD.Comment: Accepted with IEEE Geoscience and Remote Sensing Magazine. More than
300 papers relevant to the RSOD filed were reviewed in this surve
Satellite Imagery Multiscale Rapid Detection with Windowed Networks
Detecting small objects over large areas remains a significant challenge in
satellite imagery analytics. Among the challenges is the sheer number of pixels
and geographical extent per image: a single DigitalGlobe satellite image
encompasses over 64 km2 and over 250 million pixels. Another challenge is that
objects of interest are often minuscule (~pixels in extent even for the highest
resolution imagery), which complicates traditional computer vision techniques.
To address these issues, we propose a pipeline (SIMRDWN) that evaluates
satellite images of arbitrarily large size at native resolution at a rate of >
0.2 km2/s. Building upon the tensorflow object detection API paper, this
pipeline offers a unified approach to multiple object detection frameworks that
can run inference on images of arbitrary size. The SIMRDWN pipeline includes a
modified version of YOLO (known as YOLT), along with the models of the
tensorflow object detection API: SSD, Faster R-CNN, and R-FCN. The proposed
approach allows comparison of the performance of these four frameworks, and can
rapidly detect objects of vastly different scales with relatively little
training data over multiple sensors. For objects of very different scales (e.g.
airplanes versus airports) we find that using two different detectors at
different scales is very effective with negligible runtime cost.We evaluate
large test images at native resolution and find mAP scores of 0.2 to 0.8 for
vehicle localization, with the YOLT architecture achieving both the highest mAP
and fastest inference speed.Comment: 8 pages, 7 figures, 2 tables, 1 appendix. arXiv admin note:
substantial text overlap with arXiv:1805.0951
Binary Patterns Encoded Convolutional Neural Networks for Texture Recognition and Remote Sensing Scene Classification
Designing discriminative powerful texture features robust to realistic
imaging conditions is a challenging computer vision problem with many
applications, including material recognition and analysis of satellite or
aerial imagery. In the past, most texture description approaches were based on
dense orderless statistical distribution of local features. However, most
recent approaches to texture recognition and remote sensing scene
classification are based on Convolutional Neural Networks (CNNs). The d facto
practice when learning these CNN models is to use RGB patches as input with
training performed on large amounts of labeled data (ImageNet). In this paper,
we show that Binary Patterns encoded CNN models, codenamed TEX-Nets, trained
using mapped coded images with explicit texture information provide
complementary information to the standard RGB deep models. Additionally, two
deep architectures, namely early and late fusion, are investigated to combine
the texture and color information. To the best of our knowledge, we are the
first to investigate Binary Patterns encoded CNNs and different deep network
fusion architectures for texture recognition and remote sensing scene
classification. We perform comprehensive experiments on four texture
recognition datasets and four remote sensing scene classification benchmarks:
UC-Merced with 21 scene categories, WHU-RS19 with 19 scene classes, RSSCN7 with
7 categories and the recently introduced large scale aerial image dataset (AID)
with 30 aerial scene types. We demonstrate that TEX-Nets provide complementary
information to standard RGB deep model of the same network architecture. Our
late fusion TEX-Net architecture always improves the overall performance
compared to the standard RGB network on both recognition problems. Our final
combination outperforms the state-of-the-art without employing fine-tuning or
ensemble of RGB network architectures.Comment: To appear in ISPRS Journal of Photogrammetry and Remote Sensin
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