Small Infrared Target Detection Research Articles

Infrared Small Target Detection Using Homogeneity-Weighted Local Contrast Measure

Detecting small targets in infrared (IR) image sequences is an important task in IR guidance systems. The clutter of complex backgrounds often submerges small targets, making detection difficult. Achieving high detection and low false alarm rates with complex backgrounds is a primary problem. We propose an IR small target detection method using our new homogeneity-weighted local contrast measure (HWLCM). Inspired by the ability of the human visual system (HVS) to determine saliency characteristics, we implement our method to use the local contrast features of the central and surrounding regions and the weighted homogeneity characteristics of the surrounding regions to enhance the target while suppressing the complex background. Our method divides each image into blocks with a sliding window for which the HWLCM is calculated. The HWLCM enhances the actual target and suppresses interference simultaneously. We apply an adaptive threshold to target region extraction to further refine the results. Our experimental results show that our proposed method is more effective than six comparable methods, especially in terms of the signal-to-clutter gain (SCRG) and background suppression factor (BSF) indicators.

Small infrared target detection using absolute average difference weighted by cumulative directional derivatives

Infrared search and track (IRST) systems have attracted more attention in recent years due to advances of infrared imaging technology. In a typical IRST system, small infrared detection algorithm is the most challenging part of the system development procedure. In this paper, an effective algorithm based on the average absolute gray difference (AAGD) is presented. In the first step, the main deficiencies of the AAGD algorithm are investigated precisely. After identifying three major drawbacks of the AAGD algorithm, a powerful small target detection algorithm is developed through compensating every single weak-spot in the AAGD algorithm. The simulation results on real infrared images prove that the proposed algorithm not only compensates the AAGD disadvantages but also outperforms the recently published well-known small infrared target detection algorithms in both qualitative and quantitative perspectives.

Infrared dim and small target detection based on two-stage U-skip context aggregation network with a missed-detection-and-false-alarm combination loss

Infrared small target detection (ISTD) is a critical technique in both civil and military applications such as leak and defect inspection, cell segmentation for medicine analysis, early-warning systems and so on. Over the last decade, numerous ISTD methods have been proposed, such as methods based on image denoising, visual saliency detection, low-rank matrix recovery and traditional machine learning, but training an end-to-end deep model to detect small targets has not been fully investigated. In this regard, the paper proposes a novel deep model called UCAN for ISTD which concatenates two context aggregation networks and connects them using U-skip connections. A Missed-detection-and-False-alarm Combination(MFC) loss function, which is based on the Neyman-Pearson decision theory, is proposed to train the model and can well balance the detection rate and the false alarm rate. In addition, a two-stage detection scheme which involves a cascade of two UCANs is proposed to further improve the overall detection performance of ISTD. Extensive experiments on real infrared sequences and a single-frame image set and the comparison with state-of-the-art methods demonstrate the superiority of the proposed model.

AS-CRI: A New Metric of FTIR-Based Apparent Spectral-Contrast Radiant Intensity for Remote Thermal Signature Analysis

Infrared signature analysis that considers both the target and background is fundamentally important to the development of target detection systems as well as in the design of ships for thermal stealth. This paper presents the analysis results of long-term infrared signature variations in terms of the apparent spectral-contrast radiant intensity measured using Fourier transform infrared (FTIR)-based hyperspectral images. A novel apparent spectral-contrast radiant intensity (AS-CRI) measure is proposed to evaluate the spectral infrared signature accurately at the sensor point of view. The spectral information by AS-CRI can provide the optimal band for either target detection or thermal stealth purposes, considering the background and atmospheric transmittance. In addition, the effects of seasonal and weather variations were analyzed from the long-term hyperspectral image database constructed during 2018.01–2018.08 (three times a day). A TELOPS HYPER-CAM MWE camera was adopted to acquire 374 bands in 1.5–5.5 μm. The automatic weather system (AWS) can provide 24 h weather recordings for the signature evaluation. The experimental results validate the utility of the novel AS-CRI method to find spectral bands for a range of infrared signature applications including small infrared target detection.

Simplified method for small infrared target detection against gentle background movement

The small infrared target against a great movement background can be detected by calculating its optical flow field to estimate and compensate for the movement background, but the target against gentle movement background has a large computational complexity for calculating its optical flow field. Therefore, this paper proposed a simplified method for detecting a small infrared target against a gentle movement background, considering that the background has no rotational movement and perspective relationship. It uses the translational motions in the horizontal and vertical directions to represent background movement. It uses the minimum variance of the difference in the gray scale between previous and posterior frames to estimate the background movement in the horizontal and vertical directions; it then uses the differential method and the morphological process to detect a moving small target. The results from measurement sequences show that the proposed method can detect infrared targets against gentle background movement and that its computational complexity is greatly reduced.

Infrared small-target detection under complex background based on subblock-level ratio-difference joint local contrast measure

It is always a challenging task to detect an infrared (IR) small target with high-detection rate, low false alarm rate, and high detection speed since the target usually has a small size and dim gray value, and the background is usually complex. Local contrast, which is based on the human visual system, has been proved efficient for IR small target detection, but existing local contrast algorithms are either difference-form or ratio-form and cannot enhance true target and suppress background simultaneously. In addition, most of them are pixel-level algorithms and require a huge amount of calculations. A simple but efficient method named subblock-level ratio-difference joint local contrast measure (SRDLCM) is proposed; it can enhance real small target and suppress complex background simultaneously. In addition, SRDLCM is calculated for each subblock but not each pixel, so its calculation amount can be reduced significantly. The experimental results on seven real IR sequences and one single-frame image dataset show that the proposed algorithm can achieve a good detection performance in detection rate and false alarm rate with a good robustness, and the time consumed for a single frame is only less than 0.04 s.

Derivative Entropy-Based Contrast Measure for Infrared Small-Target Detection

Robust and effective detection of small target and false alarm (FA) suppression are the key techniques in infrared search and track systems. In this paper, the derivative entropy-based contrast measure (DECM) is proposed for small-target detection under various complex background clutters. Initially, different directional derivatives of an infrared image are calculated based on the facet model. Then, by analyzing the derivative properties of small target, the primitive entropy formula is improved by incorporating derivative information. With the improved entropy, the contrast measure is constructed to enhance small target and suppress background clutters in each derivative subband. Finally, the contrast measure maps derived from derivative subbands are fused together. The small target could be segmented easily from the fusion result. Experimental results demonstrate that DECM could effectively enhance dim small targets and suppress complex background clutters. Besides, DECM is also robust to infrared small-target images with noises of different levels. The detection results achieve higher detection ratio and lower FA compared with those of other methods under various infrared scenes.

An infrared small target detection method based on multiscale local homogeneity measure

Infrared (IR) small target detection plays an important role in the field of image detection area owing to its intrinsic characteristics. This paper presents a multiscale local homogeneity measure (MLHM) for infrared small target detection, which can enhance the performance of IR small target detection system. Firstly, intra-patch homogeneity of the target itself and the inter-patch heterogeneity between target and the local background regions are integrated to enhance the significant of small target. Secondly, a multiscale measure based on local regions is proposed to obtain the most appropriate response. Finally, an adaptive threshold method is applied to small target segmentation. Experimental results on three different scenarios indicate that the MLHM has good performance under the interference of strong noise.

High-Boost-Based Multiscale Local Contrast Measure for Infrared Small Target Detection

Robust and efficient infrared (IR) small target detection plays an important role in image processing for IR remote sensing. In order to detect the IR small target with high detection rate, low false alarm rate (FAR), and high detection speed, a novel method called high-boost-based multiscale local contrast measure (HB-MLCM) is proposed in this letter. First, improved high boost filter is proposed to enhance the high frequency signal where the target may appear and suppress the low frequency signal. Then, a simple MLCM is proposed for further enhancing the target and suppressing the background. Finally, a simple and adaptive thresholding method is used to segment targets from the contrast map. Experimental results on three real image sequences with various typical complex backgrounds demonstrate that the proposed method can effectively detect the target with faster speed, higher detection rate, and lower FAR compared with the state-of-the-art methods.

IR small target detection based on human visual attention using pulsed discrete cosine transform

Detection of small targets in an infrared (IR) image with high reliability is very important for defence systems. Small targets in an IR image are defined as salient features which attract the attention of human visual system. In this study, a robust method for detection of small targets in an IR image is proposed based on HV attention. In this method, first, the Gaussian-like feature maps are extracted from the original image. Then, saliency maps (SMs) are created based on pulsed discrete cosine transform, in which the target is salient and background clutter is suppressed. Finally, to increase the contrast between target and background clutter and to raise robustness of this method against false alarms, SMs are fused adaptively. Experiments are carried out on the data set including real-life IR images with small targets as well as various and complicated backgrounds. Qualitative and quantitative assessments show that the proposed method can detect small targets in IR image with high reliability and is more effective compared with other methods based on HV attention. Therefore, it can be used in many applications for detection of small targets in IR image with minimum false alarms.

Effective Infrared Small Target Detection Utilizing a Novel Local Contrast Method

Effective detection of small targets plays a pivotal role in infrared (IR) search and track applications for modern military defense or attack. Consequently, an effective small IR target detection algorithm based on a novel local contrast measure (NLCM) is proposed in this letter. Initially, difference of Gaussian band-pass filter is employed to enhance target and suppress background clutter. Then, a segmentation operation is implemented to obtain IR local regions of fixed size larger than general IR small target size. Finally, the salient map is obtained using the NLCM, and an adaptive threshold is applied to extract the target region. Experimental results on two real sequences show that the proposed method has better detection performance compared with conventional baseline methods.

An Efficient Infrared Small Target Detection Method Based on Visual Contrast Mechanism

Robust and efficient detection of an infrared (IR) small target is very important in the IR search and track system. Based on the contrast mechanism of the human visual system, an IR small target detection method with high detection rate, low false alarm rate, and short processing time is proposed in this letter. This method consists of two stages. At the first stage, with the top-hat filter and an adaptive threshold operation based on the constant false alarm rate applied to the original image, the suspicious target regions are obtained. In this way, the computing time of the following steps would be reduced a lot; meanwhile, the desired and predictable detection probability with the constant false alarm probability is maintained. At the second stage, we first define a new efficient local contrast measure between the target and the background, and the local self-similarity of an image is introduced to calculate the local saliency map. With the combination of the local self-similarity and local contrast, an efficient saliency map is obtained, which cannot only increase the signal-to-clutter ratio but also suppress residual clutter simultaneously. Then, a simple threshold operation on the saliency map is used to get the true targets. Experimental results indicate that the proposed method is superior in detection rate, false alarm rate, and processing time compared with the contrast algorithms, and it is an efficient method for IR small target detection in a complex background.

Small Infrared Target Detection Based on Weighted Local Difference Measure

Against an intricate infrared cloudy-sky background, jamming objects such as the edges of clouds in the scene have a similar thermal intensity measure with respect to the background as small targets. This may cause high false alarm rates and low probabilities of detection according to conventional small target detection methods. In this paper, we propose a weighted local difference measure (WLDM)-based scheme for the detection of small targets against various complex cloudy-sky backgrounds. Initially, a WLDM map is achieved to simultaneously enhance targets and suppress background clutters and noise. In this way, the true targets can be easily separated from jamming objects. After that, a simple adaptive threshold is used to segment the targets. More than 460 infrared small target images against diverse intricate cloudy-sky backgrounds were utilized to validate the detection capability of the WLDM-based method. Experimental results demonstrate that the proposed algorithm not only works more robustly for different cloudy-sky backgrounds, target movements, and signal-to-clutter ratio (SCR) values but also has a better performance with regard to the detection accuracy, in comparison to traditional baseline methods. In particular, the proposed method is able to significantly improve SCR values of the images.

Scale-space point spread function based framework to boost infrared target detection algorithms

Small target detection is one of the major concern in the development of infrared surveillance systems. Detection algorithms based on Gaussian target modeling have attracted most attention from researchers in this field. However, the lack of accurate target modeling limits the performance of this type of infrared small target detection algorithms. In this paper, signal to clutter ratio (SCR) improvement mechanism based on the matched filter is described in detail and effect of Point Spread Function (PSF) on the intensity and spatial distribution of the target pixels is clarified comprehensively. In the following, a new parametric model for small infrared targets is developed based on the PSF of imaging system which can be considered as a matched filter. Based on this model, a new framework to boost model-based infrared target detection algorithms is presented. In order to show the performance of this new framework, the proposed model is adopted in Laplacian scale-space algorithms which is a well-known algorithm in the small infrared target detection field. Simulation results show that the proposed framework has better detection performance in comparison with the Gaussian one and improves the overall performance of IRST system. By analyzing the performance of the proposed algorithm based on this new framework in a quantitative manner, this new framework shows at least 20% improvement in the output SCR values in comparison with Laplacian of Gaussian (LoG) algorithm.

Multiscale patch-based contrast measure for small infrared target detection

Infrared (IR) small target detection plays an important role in IR guidance systems. In this paper, a biologically inspired method called multiscale patch-based contrast measure (MPCM) is proposed for small IR target detection. MPCM can increase the contrast between target and background, which makes it easy to segment small target by simple adaptive thresholding method. Experimental results on three sequences demonstrate that the proposed small target detection method can not only suppress background clutter effectively even if with strong noise interference, but also detect targets accurately with low false alarm rate and high speed.

An infrared small target detection algorithm based on high-speed local contrast method

Small-target detection in infrared imagery with a complex background is always an important task in remote sensing fields. It is important to improve the detection capabilities such as detection rate, false alarm rate, and speed. However, current algorithms usually improve one or two of the detection capabilities while sacrificing the other. In this letter, an Infrared (IR) small target detection algorithm with two layers inspired by Human Visual System (HVS) is proposed to balance those detection capabilities. The first layer uses high speed simplified local contrast method to select significant information. And the second layer uses machine learning classifier to separate targets from background clutters. Experimental results show the proposed algorithm pursue good performance in detection rate, false alarm rate and speed simultaneously.

Small infrared target detection based on image patch ordering

Small infrared (IR) target detection is an important and challenging issue in IR target tracking system. In this paper, a patch ordering-based method is proposed for small IR target detection in an image with complicated background. Inspired by the contrast mechanism of human vision system, a patch ordering-based contrast measure (POCM) is designed to deal with the input image, which cannot only suppress the background noise and clutter but also enhance the targets significantly. In this way, POCM can increase the contrast ratio between target and background. This leads to higher Signal Clutter Ratio (SCR). Then the true target can be detected by applying simple adaptive thresholding method. The experimental results on two sequences show that the proposed method can efficiently detect small IR target from heavy clutter.

Low-Rank and Sparse Decomposition Based Frame Difference Method for Small Infrared Target Detection in Coastal Surveillance

Low-Rank and Sparse Decomposition Based Frame Difference Method for Small Infrared Target Detection in Coastal Surveillance

An Infrared Small Target Detecting Algorithm Based on Human Visual System

Infrared (IR) small target detection with high detection rate, low false alarm rate, and multiscale detection ability is a challenging task since raw IR images usually have low contrast and complex background. In recent years, robust human visual system (HVS) properties have been introduced into the IR small target detection field. However, existing algorithms based on HVS, such as difference of Gaussians (DoG) filters, are sensitive to not only real small targets but also background edges, which results in a high false alarm rate. In this letter, the difference of Gabor (DoGb) filters is proposed and improved (IDoGb), which is an extension of DoG but is sensitive to orientations and can better suppress the complex background edges, then achieves a lower false alarm rate. In addition, multiscale detection can be also achieved. Experimental results show that the IDoGb filter produces less false alarms at the same detection rate, while consuming only about 0.1 s for a single frame.

Biologically inspired small infrared target detection using local contrast mechanisms

In order to obtain higher small target detection accuracy, this paper presents an effective algorithm inspired by the local contrast mechanism. The proposed method can enhance target signal and suppress background clutter simultaneously. In the first stage, a enhanced image is obtained using the proposed Weighted Laplacian of Gaussian. In the second stage, an adaptive threshold is adopted to segment the target. Experimental results on two challenging image sequences show that the proposed method can detect the bright and dark targets simultaneously, and is not sensitive to sea–sky line of the infrared (IR) image. So it is fit for small IR target detection.