Object detection for noncooperative targets using HOG-based proposals

Object detection in images is a computing demanding task which usually needs to deal with the detection of different classes of objects, and thus requiring variations and adaptations easily provided by software solutions. Object detection algorithms are being part of real-time smarter embedded systems, such as automotive, medical, robotics and security systems. In most embedded systems, efficient implementations of object oriented algorithms need to provide high performance, low power consumption, and programmability to allow greater development flexibility. The Histogram of Oriented Gradients (HOG) is one of the most widely used algorithms for object detection in images. In this paper, we show our work towards mapping the HOG algorithm to an FPGA-based system consisting of multiple Nios II softcore processors and bearing in mind high-performance and programmability issues. We show how to reduce 19x the algorithms execution time by source to source transformations and specially avoiding redundant processing. Furthermore, we show how the use of pipelining processing using three Nios II processors allows a speedup of 49x compared to the embedded baseline application.

Object region proposal has a wide application on various domains, such as object detection, object tracking, robot navigation, and anomaly detection. Widely used region proposal methods are based on either grouping superpixels or sliding windows. Previous studies have been done by grouping either convolution features, superpixels, or windows. Moreover, histogram of gradients (HoGs) of lower-level features (pixels) can be used for the region proposal task. In this study, both the concepts of HoGs and convolution features are used for proposing object(s) region(s) in an image. Region proposal is done by HoGs of convolution features and statistical application on the gradient data of different feature maps. First, a sized image is passed through one convolution layer to generate reduced feature maps. Then, a window slides over each feature map and HoG is applied over each window. Thereafter, the histogram is analysed using the concept of Coefficient of Variation (CV) and angle (slope) applied on histogram data values. A window is considered as the object region if the CV and angle of its histogram data exceed some thresholds. For all feature maps, we have obtained several widows that represent approximated object regions. These windows are grouped to obtain the possible region(s) proposal. The effectiveness of the proposed method is demonstrated over one of the benchmark datasets, called `PASCAL VOC'. Our method is found superior to two other state-of-the-art, namely region-based segmentation (RBS), and combining efficient object localization and image classification (CEOLIC) in terms of recall.

A fusion of dolphin swarm optimization and improved sine cosine algorithm for automatic detection and classification of objects from surveillance videos

Object detection and localization in an image can be achieved by representing an object as a Histogram of Oriented Gradients (HOG). HOGs have proven to be robust object descriptors. However, to achieve accurate object localization, one must take a sliding window approach and evaluate the similarity of the descriptor over all possible windows in an image. In case that search should also be scale and rotation invariant, the exhaustive consideration of all possible HOG transformations makes the method impractical due to its computational complexity. In this work, we first propose a variant of an existing rotation invariant HOG-like descriptor. We then formulate object detection and localization as an optimization problem that is solved using the Particle Swarm Optimization (PSO) method. A series of experiments demonstrates that the proposed approach results in very large performance gains without sacrificing object detection and localization accuracy.KeywordsParticle Swarm OptimizationObject DetectionLocalization AccuracyObject LocalizationReference ObjectThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Fire is a disaster caused by accidental fire, unexpected or unwanted, difficult to control, and detrimental. Many factors cause fires. Humans may directly or indirectly cause these factors, or they may also be caused by nature. Total 913 residential fires were recorded in Indonesia from 2013 to 2015. There are still many incidents of a fire occurring. This research is carried out to reduce the incident to detect fire objects by applying the histogram of oriented gradient (HOG) method and then classified using the support vector machine (SVM) method. The proposal is expected to help in the early identification of fires to reduce the number of fires that occur. This study has several stages: inserting images, converting images to grayscale, thresholding methods, object detection with HOG, and classification using SVM. The system implementation is carried out using the Python programming language with the Django web framework. The final result will be tested using a confusion matrix with four matrices: accuracy, precision, recall, and F1-Score. The results showed that the HOG and SVM methods using the RBF kernel and the sharing of training-test data 70:30 obtained accuracy of 88.33%, precision of 85.71 %, recall of 88.89%, and F1-Score of 87. 27%.

Compared with the traditional object detection algorithm, the object detection algorithm based on deep learning has stronger robustness to complex scenarios, which is the hot direction of current research. According to the process characteristics of the object detection algorithm based on deep learning, it is divided into two-stage object detection algorithm and single-stage object detection algorithm, focusing on the problems solved by some classical algorithms and their advantages and disadvantages. In view of the problem of object detection, especially small object detection, the commonly used data sets and performance evaluation indicators are summarized; the characteristics, advantages, and detection difficulties of various common data sets are compared; the challenges faced by commonly used object detection methods and small object detection are systematically summarized; the latest work of small object detection methods based on deep learning is sorted out; and the small object detection methods based on multiscale and small object detection methods based on super-resolution are introduced. At the same time, the lightweight strategy for target detection methods and the performance of some lightweight models are introduced; the characteristics, advantages, and limitations of various methods are summarized; and the future development direction of small object detection methods based on deep learning is prospected.

Low-light object detection involves identifying and locating objects in images captured under poor lighting conditions. It plays a significant role in surveillance and security, night pedestrian recognition, and autonomous driving, showcasing broad application prospects. Most existing object detection algorithms and datasets are designed for normal lighting conditions, leading to a significant drop in detection performance when applied to low-light environments. To address this issue, we propose a Low-Light Detection with Low-Light Enhancement (LDWLE) framework. LDWLE is an encoder-decoder architecture where the encoder transforms the raw input data into a compact, abstract representation (encoding), and the decoder gradually generates the target output format from the representation produced by the encoder. Specifically, during training, low-light images are input into the encoder, which produces feature representations that are decoded by two separate decoders: an object detection decoder and a low-light image enhancement decoder. Both decoders share the same encoder and are trained jointly. Throughout the training process, the two decoders optimize each other, guiding the low-light image enhancement towards improvements that benefit object detection. If the input image is normally lit, it first passes through a low-light image conversion module to be transformed into a low-light image before being fed into the encoder. If the input image is already a low-light image, it is directly input into the encoder. During the testing phase, the model can be evaluated in the same way as a standard object detection algorithm. Compared to existing object detection algorithms, LDWLE can train a low-light robust object detection model using standard, normally lit object detection datasets. Additionally, LDWLE is a versatile training framework that can be implemented on most one-stage object detection algorithms. These algorithms typically consist of three components: the backbone, neck, and head. In this framework, the backbone functions as the encoder, while the neck and head form the object detection decoder. Extensive experiments on the COCO, VOC, and ExDark datasets have demonstrated the effectiveness of LDWLE in low-light object detection. In quantitative measurements, it achieves an AP of 25.5 and 38.4 on the synthetic datasets COCO-d and VOC-d, respectively, and achieves the best AP of 30.5 on the real-world dataset ExDark. In qualitative measurements, LDWLE can accurately detect most objects on both public real-world low-light datasets and self-collected ones, demonstrating strong adaptability to varying lighting conditions and multi-scale objects.

In complex scene, considering traditional object detection methods based on feature points have exposed many problems, such as undetected points, low detected ratio and cannot well process object occlusion and scaling situation, this paper proposes a detection method which based on a deformable part model. The method uses histogram of oriented gradient (HOG) feature as the object description, and the deformable part model includes a global template and several high-resolution templates. And the method uses the support vector machine (SVM) training the object model. In the learning process, after the HOG feature extracted, the method modifies the HOG feature, and then uses the principal component analysis (PCA) method reducing feature dimensions to avoid over-learning, and improve the detection rate in the detection process. The experiment results shows that the method proposed can better process object occlusion or scaled situation, and there’s also an improvement in detection ratio.

Research in automated object detection has mainly addressed detection in 2-D intensity images. The best performing systems exhibit a high degree of robustness to variation in object scale, rotation and viewpoint. Depending on the context of the detection task, rotation and viewpoint can be controlled for, but estimating object scale is usually not possible without additional sensing apparatus. Objects must be searched for at all scales where they are likely to be present. Range sensors allow for direct distance measurements to be taken and the generation of range maps or point clouds that when co-registered against standard 2-D visual images create 3-D images. Knowledge of depth obviates the need to search over the entire scale space for an object, but this also allows for the object's scale itself to be incorporated into the detection scheme. Most existing object detection schemes use range only to constrain the detection search space or to discard detections that do not match the expected object scale. This paper presents a novel feature extraction and detection method that calculates scale proportionate histograms of oriented gradients (Pro-HOG) by exploiting known depth in an image. Pro-HOG is evaluated against a reference implementation of the original histograms of oriented gradients (HOG) feature extractor for detection of images of cars in the PASCAL Visual Object Classes 2007 dataset. High quality detection results are achieved on the real world Earthmine dataset using a Pro-HOG feature detector trained with the PASCAL VOC 2007 dataset. It is demonstrated that Pro-HOG's detection accuracy is comparable to HOG but at much reduced computational overhead.

Cars can appear at any orientations in satellite images, but the widely used traditional histogram of oriented gradient (HOG) features is not rotation-invariant. Recently, a rotation-invariant HOG descriptor using Fourier analysis in polar coordinators has been proposed and has shown good performance; however, it is time and memory consuming. In this study, the authors improve this method to present an efficient rotation-invariant HOG descriptor for car detection in satellite images. The authors first convert spatial convolutions to multiplications in the frequency domain based on fast Fourier transform to speed up the descriptor computation. Then, they employ a backward search feature selection method based on support vector machine to reduce the descriptor dimensionality. This allows them to build the proposed efficient rotation-invariant HOG descriptor at low time and memory cost. The authors demonstrate that their method is more efficient and yields better detection performance in a public dataset for car detection task in satellite images.

Object detection is to accurately identify and locate the target in the image. With the development of deep learning, object detection algorithm has achieved very high achievements, for example, object detection algorithm is applied to security, medical, transportation, military, automatic driving and so on. This paper reviews the progress of target detection algorithms by consulting many literatures at home and abroad. Firstly, the research status of object detection is introduced, and the dataset, evaluation index and convolutional neural network used in the process of target detection are provided. Secondly, it compares some mainstream object detection algorithms at this stage. The starting point of this paper is to help others quickly understand the target detection algorithm. Readers can find the appropriate object detection algorithm according to their own project and improve it on this basis. Finally, combined with the current research hotspots, the future development trend is analyzed.

Object proposal algorithms have shown great promise as a first step for object recognition and detection. Good object proposal generation algorithms require high object detection recall rate as well as low computational cost, because generating object proposals is usually utilized as a preprocessing step. The problem of how to accelerate the object proposal generation and evaluation process without decreasing recall is thus of great interest. In this paper, we propose a new object proposal generation method using two-stage cascade support vector machines (SVMs), where in the first stage linear filters are learned for predefined quantized scales/aspect-ratios independently, and in the second stage a global linear classifier is learned across all the quantized scales/aspect-ratios for calibration, so that all the windows from the first stage can be compared properly. The windows with highest scores from the second stage are kept as inputs to our new efficient proposal calibration algorithm to improve their localization quality significantly, resulting in our final object proposals. We explain our scale/aspect-ratio quantization scheme, and investigate the effects of combinations of l1 and l2 regularizers in cascade SVMs with/without ranking constraints in learning. Comprehensive experiments on VOC2007 dataset are conducted, and our method is comparable with the current state-of-the-art methods with much better computational efficiency.

A non-cooperative target grasping position prediction model for tethered space robot

In recent years, computer vision technology has developed rapidly, as one of its important research directions, object detection has received widespread attention due to its high accuracy. Meanwhile, object detection has many application fields, such as intelligent transportation, medical and health, security systems, etc. Traditional object detection methods have limitations when applied to complex real-world scenarios. To improve the shortcomings of conventional methods, deep learning based object detection algorithms have significantly improved the efficiency of object detection and become a research hotspot in object detection. This article summarizes the algorithms into two-stage and one-stage object detection algorithms based on the technical processes and structural differences in handling object detection tasks. Firstly, several common two-stage and one-stage object detection algorithms and their applications in real-world scenarios are introduced. Then their data sets and algorithm performance are analyzed and compared. Finally, according to the results of the comparison, the existing problems of the two-stage object detection algorithm and the one-stage object detection method are discussed, and their future development directions are pointed out.

Object detection is a major branch and fundamental task in computer vision, aiming to localize, identify and classify even the smallest objects of interest in images. Features can be extracted efficiently by deep convolutional neural networks (CNNs) as the backbone for real-time or near real-time object detection performance than the hand-crafted-based traditional methods. In the past few years, the advent of transformer-based models with robust self-attention mechanisms has not only raised object detection performance to a higher level but has also enabled it to produce excellent results. Many object detection tasks in the real world require that 3D information about the object be obtained, thus strengthening active research in 3D object detection. However, the algorithms for detecting 3D objects are not easy to propagate in real-world applications due to many factors, making reconstruction of 2D object detection algorithms to 3D object detection algorithms the suitable alternative. Therefore, we review the evolution of 2D object detection algorithms for digital imaging applications, focusing on their developments, models, applications, datasets, evaluation metrics, strengths and weaknesses, for better understanding of their landmarks and contributions to the advancement of the field.