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In this paper, we demonstrate three experimental approaches to improve the performance of lock-in thermography (LIT). The infrared imaging (IR) technique is extensively used for failure analysis (FA) in the semiconductor industry. However, with the conventional LIT, low-contrast topography images can be obtained at room temperature due to the poor emissivity gradient in the devices and the limitation on the performance of the infrared camera. The grayscale topographical contrast is improved significantly when the device under test is heated from room temperature to 90 °C. A compact printed circuit board heater is designed and customized for this application. Furthermore, the heater can also be used in the lock-in loop to get the enhanced topography images. These methods are implemented experimentally, and the results are validated using finite element simulation. The thermal enhancement approaches proposed in this paper are demonstrated at die level on a defective silicon interposer sample. The topographical contrast and the signal intensity of the hotspot obtained are enhanced when compared to the classical LIT performed at room temperature. To reduce the thermal budget of the heat-assisted method, dual LIT is developed where the two consecutive lock-in measurements are performed to obtain hotspot amplitude and topography image with good contrast. In addition, the topography image obtained from this technique is less susceptible to input noise levels. To increase the throughput of the FA process, quadrature lock-in thermography, a dual-purpose measurement technique is shown. A high-contrast topography image and the hotspot location are obtained from the same lock-in thermogram by performing trigonometric conditioning. The throughput from this approach is the same as the classical LIT technique. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the performance of dual-energy window (DEW) and triple-energy window (TEW) scatter correction methods in cardiac SPECT imaging with technetium-99m (Tc-99m) and thallium-201 (Tl-201) radioisotopes. Materials and Methods: The SIMIND Monte Carlo program was used to simulate the imaging system and produce the required projections. Two phantoms, including the simple cardiac phantom and the NCAT phantom, were used to evaluate the scatter correction methods. The simulations were repeated 5 times for each phantom and finally, the mean values obtained from these 5 tests were used in the analysis of the results. Results: The obtained results from this study show that in the case of both investigated phantoms, the use of correction methods leads to improve the contrast of the images obtained from Tc-99m and Tl-201 radioisotopes. In the case of the simple cardiac phantom, the use of DEW and TEW correction methods leads to a relative increase in image contrast of about 23.88% and 12.23% for 99mTc radioisotope and about 29.19% and 20.98% for 201Tl radioisotope, respectively. This relative increase in the case of the NCAT phantom is about 22.48% and 19.43% for 99mTc radioisotope and about 27.74% and 24.74% for 201Tl radioisotope, respectively. Conclusion: According to the obtained results, despite the higher contrast of the noncorrected images of 99mTc radioisotope, the relative increase in contrast of the corrected images of 201Tl radioisotope is more than that of 99mTc radioisotope. Furthermore, for both radioisotopes, the relative increase related to the DEW method is higher than the TEW method.

AbstractPurposeMethodsResultsConclusionNeodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered gold standard in the treatment of posterior capsule opacification (PCO). In this laboratory study, we measured spectral transmission to evaluate the image contrast and analyze the impact of Nd:YAG associated defects in presbyopia-correcting intraocular lenses (IOLs).Two hydrophobic, acrylic IOLs as classic multifocal lenses with diffractive ring segments and different amount of near addition (A, B), one hydrophilic, trifocal IOL (C), one sector-shaped, plate haptic IOL (D) and one hydrophobic, enhanced depth of focus (EDOF) IOL (E) were studied. Measurements included surface topography characterization, United States Air Force resolution test chart (USAF) analysis, spectral transmittance measurements and through focus contrast measurement. Measurements were done with unaltered samples, damages (n = 7) were intentionally created in the central 3.5 mm zone using a photodisruption laser (2.0 mJ) and measurements were repeated.Significant differences were shown between unmodified samples and samples with YAG pits. The YAG-pits decreased the image contrast and spectral transmission and changed results of USAF test images. The imaging contrast decreased to 66%, 64%, 60%, 52% and 59% with the YAG shots in samples (A-E). The light transmission decreased to 88%, 87%, 92%, 79% and 91% (A-E) on average between 400 nm to 800 nm. In all IOLs a reduction of the relative intensity of transmitted light was observed.The image performance of all tested presbyopia-correcting IOLs is significantly influenced and disturbed by YAG-pits. The intensity of transmitted light is reduced in the wavelength between 450–800 nm. USAF test targets show worse results compared to unmodified samples and contrast is significantly deteriorated. No ranking/rating among tested IOLs should be made as many other factors play a role in real world scenario. High care should be taken when performing Nd:YAG capsulotomy on premium IOLs to avoid any damages. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study is to investigate whether the results of pelvimetry using original radiographic Martius images and the same images with high‐pass filtering applied ("edge images") would be consistent. Methods: A total of 30 primagravidas were included in this study. Three obstetricians independently measured the anteroposterior and transverse diameters of the pelvic inlet in the original and the edge images, recording the x‐ and y‐coordinates of the four endpoints. A Wilcoxon signed rank sum test was performed on the coordinate data to evaluate differences between the original and edge images. Results: In the analysis of all coordinate data, statistically significant differences were found in both x‐ and y‐coordinates of the sacral promontory point (SPP). In the y‐coordinate of the SPP, a statistically significant difference was found in 9 of 30 pairs of images, and in all 9 the anteroposterior diameter was shorter in the edge images compared to the original images due to the more caudal placement of the SPP. Conclusions: The coordinates of the SPP on original radiographs and their edge images were not consistent in pelvimetry using Martius images. Our results suggest that improved image contrast will allow obstetricians to better assess pelvic narrowing and cephalopelvic disproportion and even reduce radiographic dose, thereby reducing risks for pregnant women and their fetuses. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the performance of dual-energy window (DEW) and triple-energy window (TEW) scatter correction methods in cardiac SPECT imaging with technetium-99m (Tc-99m) and thallium-201 (Tl-201) radioisotopes. Materials and Methods: The SIMIND Monte Carlo program was used to simulate the imaging system and produce the required projections. Two phantoms, including the simple cardiac phantom and the NCAT phantom, were used to evaluate the scatter correction methods. The simulations were repeated 5 times for each phantom and finally, the mean values obtained from these 5 tests were used in the analysis of the results. Results: The obtained results from this study show that in the case of both investigated phantoms, the use of correction methods leads to improve the contrast of the images obtained from Tc-99m and Tl-201 radioisotopes. In the case of the simple cardiac phantom, the use of DEW and TEW correction methods leads to a relative increase in image contrast of about 23.88% and 12.23% for 99mTc radioisotope and about 29.19% and 20.98% for 201Tl radioisotope, respectively. This relative increase in the case of the NCAT phantom is about 22.48% and 19.43% for 99mTc radioisotope and about 27.74% and 24.74% for 201Tl radioisotope, respectively. Conclusion: According to the obtained results, despite the higher contrast of the noncorrected images of 99mTc radioisotope, the relative increase in contrast of the corrected images of 201Tl radioisotope is more than that of 99mTc radioisotope. Furthermore, for both radioisotopes, the relative increase related to the DEW method is higher than the TEW method. [ABSTRACT FROM AUTHOR]

Abstract Objective To compare the image quality of normal anatomical structures and radiation dose on low-dose (LDCT) and standard-dose (SDCT) temporal bone CT in children. Methods The study included 45 LDCT (80 kV and 130 mAs) and 45 SDCT (120 kV and 170 mAs) scans in children, 1–15 years of age. LDCT and SDCT scans were analyzed on H60s and H70h reconstruction kernels, respectively. Two readers assessed the image quality for 25 anatomical structures, using a 5-point scale. A score of 3 and above was considered “sufficient” and 2 and below was considered “insufficient” image quality. Image noise, contrast, age and size-specific effective doses were calculated. Results Despite an increase in image noise on LDCT, image quality remained sufficient for most structures owing to increased image contrast. The median effective dose on LDCT, calculated with age-specific conversion factor, decreased by 72.9% and that calculated with size-specific conversion factor decreased by 81.8% compared to the dose on SDCT. Conclusion LDCT provides comparable image quality for evaluation of temporal bone with significant reduction in radiation dose in children.

The art of light engineering unveils a world of possibilities through the meticulous manipulation of photonic properties such as intensity, phase, and polarization. Precision control over these properties finds application in a variety of fields spanning communications, light–matter interactions, laser direct writing, and imaging. Terahertz (THz) range, nestled between microwaves and infrared light, stands out for its remarkable ability to propagate with minimal losses in numerous dielectric materials and compounds, making THz imaging a powerful tool for noninvasive control and inspection. In this study, a rational framework for the design and optimal assembly of nonparaxial THz imaging systems is established. The research is centered on lensless photonic systems composed solely of high‐resistivity silicon‐based nonparaxial elements such as the Fresnel zone plate, the Fibonacci lens, the Bessel axicon, and the Airy zone plate, all fabricated using laser ablation technology. Through a comprehensive examination through illumination engineering and scattered light collection from raster‐scanned samples in a single‐pixel detector scheme, the imaging systems are evaluated via diverse metrics including contrast, resolution, depth of field, and focus. These findings chart an exciting course toward the development of compact and user‐friendly THz imaging systems where sensors and optical elements seamlessly integrate into a single chip. [ABSTRACT FROM AUTHOR]

In this study, we design an ultra-low self-heating radiation long-wave infrared laser communicationoptical system, which mainly includes aperture stop, primary mirror, secondary mirror, three-mirror,field stop, four-mirror, window glass, detector light shield, and image plane. The system enters apupil diameter of 280 mm, a field of view angle of 1×1°, a system focal length of 840 mm, and awavelength of 8 − 12 μmkm; the off-axis four-fold anti-structure is adopted. The optical mirror andstructural components of the material are Aluminum, the system's own thermal radiation equivalent toa black-body temperature of 171 K. The equivalent black-body temperature of the system is measuredin a vacuum chamber. The temperature of the spacer is 100 – 120 K, the temperature of the coldplate is 85 – 87 K, and the integration time is 550 – 800 μs. At this time, the measured equivalentblack-body radiation temperature of the system is 172.9K; it is consistent with the simulation value.The design scheme solves the technical problems of low signal-to-noise ratio, poor image contrast, andshort detection distance of infrared laser communication system. [ABSTRACT FROM AUTHOR]

High-resolution imaging of Cu/low-k on-chip interconnect stacks in advanced microelectronic products is demonstrated using full-field transmission X-ray microscopy (TXM). The comparison of two lens-based laboratory X-ray microscopes that are operated at two different photon energies, 8.0 keV and 9.2 keV, shows a contrast enhancement for imaging of copper nanostructures embedded in insulating organosilicate glass of a factor of 5 if 9.2 keV photons are used. Photons with this energy (Ga-Kα radiation) are generated from a Ga-containing target of a laboratory X-ray source applying the liquid-metal-jet technology. The 5 times higher contrast compared to the use of Cu-Kα radiation (8.0 keV photon energy) from a rotating anode X-ray source is caused by the fact that the energy of the Ga-Kα emission line is slightly higher than that of the Cu-K absorption edge (9.0 keV photon energy). The use of Ga-Kα radiation is of particular advantage for imaging of copper interconnects with dimensions from several 100 nm down to several 10 nm in a Cu/SiO2 or Cu/low-k backend-of-line stack. Physical failure analysis and reliability engineering in the semiconductor industry will benefit from high-contrast X-ray images of sub-μm copper structures in microchips. [ABSTRACT FROM AUTHOR]

A novel high contrast emissive projection display (EPD) on black screen is developed, using a set of RGB emissive nanomaterials that can be selectively excited by digital projection of 3 violet‐blue wavebands. The new photoluminescent display enables a scalable and freeform emissive display onto any vehicle interior surface, without covering or hiding the original surface. For example, the set of RGB emissive materials can be applied as clear topcoat onto pitch‐black foil or substrate on vehicle dashboard or center console, showing superior image contrast in bright ambient light under lower power projection. Such high contrast free‐form emissive projection will be discussed with demos for many new vehicle interior display applications. [ABSTRACT FROM AUTHOR]

Some aspects of increasing the efficiency of noctilucent clouds ground-based observations are considered. The study of such objects is highly relevant in connection with the general problems of climate change. It is shown that the limitations on the possibility of registering the phenomenon in the optical range are associated both with the relatively low brightness of clouds of this type against the background of the twilight segment, and with the strong absorption of light by dust aerosol in the surface layer of the atmosphere. The paper substantiates the idea that the transition to observations of noctilucent clouds in the near infrared range will increase the contrast of their images in the twilight segment. This will make it possible to detect noctilucent clouds during civil twilight, including at low altitudes above the horizon. To test this assumption, shooting was carried out during the 2022 season using a CANON 2000 D camera and RG780 and RG830 infrared filters. The images revealed features morphologically similar to noctilucent clouds. An analysis of the images showed that they can hardly be associated with tropospheric clouds or anthropogenic formations. The results obtained were compared with ground-based observation data from other points, as well as with satellite information on the state of noctilucent cloud fields. This comparison showed that noctilucent clouds, which were not detected in visible light images, were highly likely to be detected in near-infrared images. The prospects for the application and development of the proposed method for ground-based registration of noctilucent clouds are also considered. [ABSTRACT FROM AUTHOR]

Contrast is not uniquely defined in the literature. There is a need for a contrast measure that scales linearly and monotonically with the optical scattering depth of a translucent scattering layer that covers an object. Here, we address this issue by proposing an image contrast metric, which we call the Haziness contrast metric. In its essence, the Haziness contrast compares normalized histograms of multiple blocks of the image, a pair at a time. Subsequently, we test several prominent contrast metrics in the literature, as well as the new one, by using milk as a scattering medium in front of an object to simulate a decline in image contrast. Compared to other contrast metrics, the Haziness contrast metric is monotonic and close to linear for increasing density of the scattering material, compared with other metrics in the literature. The Haziness contrast has a wider dynamic range, and it correctly predicts the order of scattering depth for all the channels in the RGB image. Utilization of the metric to evaluate the performance assessment of dehazing algorithms is also suggested. [ABSTRACT FROM AUTHOR]

Contrast is not uniquely defined in the literature. There is a need for a contrast measure that scales linearly and monotonically with the optical scattering depth of a translucent scattering layer that covers an object. Here, we address this issue by proposing an image contrast metric, which we call the Haziness contrast metric. In its essence, the Haziness contrast compares normalized histograms of multiple blocks of the image, a pair at a time. Subsequently, we test several prominent contrast metrics in the literature, as well as the new one, by using milk as a scattering medium in front of an object to simulate a decline in image contrast. Compared to other contrast metrics, the Haziness contrast metric is monotonic and close to linear for increasing density of the scattering material, compared with other metrics in the literature. The Haziness contrast has a wider dynamic range, and it correctly predicts the order of scattering depth for all the channels in the RGB image. Utilization of the metric to evaluate the performance assessment of dehazing algorithms is also suggested.

The prevalence of heart disease has been increasing in the last ten years. One of the cardiac diagnostic tools is echocardiography. Echocardiogram medical images provide essential information, including shape, size, pumping capacity, heart function abnormalities, and location of heart damage, but echocardiogram images have high noise content and poor contrast, as well as limitations due to differences in anatomy or body mass. This will affect the reading results of patient diagnosis. Therefore, image quality improvement is needed by removing noise and increasing image contrast. This research has improved image quality using a method with low mathematical complexity and a fast computational process. The method used is the Upsampling method to generate a reference image. The quality of the image produced was the Nearest Neighbor upsampling method: 2.8 dB, Bi-linear Interpolation: 2.78 dB, and Bi-cubic Interpolation: 2.73 dB. Furthermore, the image with the highest SNR value is processed with Histogram Matching to accelerate improving image quality. The Histogram Matching image increases quality by more than 50% with a SSIM value of 0.54. The required computational process to apply this method to each medical image has an average duration of 0.4 s. This result provides a higher value than several methods using linear scaling and speckle reducing.

In this paper, we propose an adaptive gamma transform that adjusts the local values of bright and dark parts to enhance the effect of low-illumination images, thereby improving the light component. We then apply diff texture enhancement to enhance the contrast of images processed by the Retinex algorithm, thereby optimizing the perception of overexposed and underexposed imagery. Analyze the effect of image brightness enhancement based on a nonlinear transformation combined with the LOL dataset. Use PSNR and SSIM image quality evaluation criteria to analyze the visual effect of improving low-illumination images based on Retinex theory. Create a dataset of power marketing field operation inspection images and examine the effects of overexposure and underexposure image processing on four types of images: high-voltage towers, transmission lines, high-voltage fixtures, and high-voltage wireframes, using the low-light image texture fusion algorithm based on Retinex theory. Overall, this paper’s algorithm and the three DeblurGAN and DMCNN models achieve the effect of deblurring overexposed and underexposed power marketing field operation inspection images. From the local details, the model in this paper has a better effect on the de-exposure of the image, which can provide effective help for the electric power staff to understand the situation of the electric power marketing operation site and has strong practicality.

During movement in various unpaved terrain conditions, the track impressions left over by the leading vehicles provide guiding and safe routes in the area. The delineation of these tracks captured by the images can extend immense support for guidance in real time. These tracks that look like edges in coarse-resolution images take the shape of elongated areas in fine-resolution images. In such a scenario, the high pass and edge detection filters give limited information to delineate these tracks passing through different surroundings. However, the distinct texture of these tracks assists in the delineation of these tracks from their surroundings. Gray level co-occurrence matrix (GLCM) representing the spatial relation of pixels is employed here to define the texture. The authors investigated the influence of different resolutions on the distinguishability of these tracks. The study revealed that texture plays an increasing role in distinguishing objects as the image resolution improves. The texture analysis extended to investigate the track impressions left over by the leading vehicle brings out an ample scope in delineating these tracks. The measures could improve the track contrast even better than conventional techniques. To select the most optimal contrast enhancement measure in a given scenario, authors proposed a quantified measure of track index. An investigation is made on the difference-based track index (TI) representing the mean contrast value of the track vis-à-vis off-track areas. The results show an increase in the quantified contrast from 7.83 per cent to 29.06 per cent. The proposed technique highlights the image with the highest track contrast in a given scenario. The study can lead to onboard decision-making for the rut following vehicles moving in low-contrast terrain. [ABSTRACT FROM AUTHOR]

Neodymium yttrium aluminum garnet (Nd:YAG) laser capsulotomy is considered as safe and effective method in the treatment of posterior capsule opacification. Nevertheless, side effects are described. The incorrectly adjusted focus of the laser beam during the procedure can lead to so-called YAG-pits or YAG-shots. In this experimental study, we measured spectral transmission to evaluate the image contrast and analyze the impact of YAG-pits in intraocular lenses (IOL). Acrylic, foldable, one-piece IOLs with 6.0 mm optic and different material properties were studied. These included: monofocal IOLs and enhanced monofocal IOLs with water content of 0.3%, 26.0%, and 4.0% and a refractive index of 1.49, 1.46, and 1.54, respectively. All measurements were done with new, unaltered IOLs and IOLs with YAG-pits. Damage was intentionally created, performing YAG-pits (n = 7) in the central zone (3.5 mm) using a photodisruption laser (2.0mJ). All laboratory measurements were repeated: These included surface topography characterization, United States Air Force (USAF) resolution test chart analysis, spectral transmittance measurements and through focus contrast measurement. Significant differences were found between the unaltered lenses and lenses with defects. The YAG-pits within the optic of the IOLs decreased the image contrast and spectral transmission and changed results of USAF test images at the focal position by 62%, 57% and 54%, respectively. In all IOLs a reduction of the relative intensity of total transmitted light was observed between 450 and 700 nm wavelength. This experimental study confirmed that the IOL image performance deteriorates with YAG-pits. The total intensity of transmitted light or transmittance (without scattering) was reduced in the wavelength between 450 and 700 nm. The contrast was significantly reduced and USAF test targets showed much worse results compared to unmodified counterparts. There was no systematic difference between monofocal and enhanced monofocal lenses. Further experiments should investigate the effect of YAG-pits on diffractive IOLs. [ABSTRACT FROM AUTHOR]

To reduce haze in an image, a contrast-based background and foreground channel prior (BFCP) is proposed in this work. The haze will affect both colour and contrast, and the majority of haze reduction techniques rely on the dark channel prior (DCP) as well as the dark and bright channel priors (DBCP). Even though the DCP and DBCP produced accurate results, they provide a less precise estimate of the haze depth because they do not take into account the local contrast and spikes in the haze image histogram. The goal of this BFCP is to improve the estimation of the transmission map and to correct the spikes in the histogram of the hazed image. By utilizing contrast differences in the background and foreground, BFCP improves transmission map estimates. This method is tested on images of (i) indoor haze, (ii) outdoor haze, (iii) dense haze, (iv) night haze, and (v) fog. [ABSTRACT FROM AUTHOR]

Image texture is an important part of many types of images, for example medical images. Texture Analysis is the technique that uses measurable features to categorize complex textures. The main goal is to extract discriminative features that are used in different pattern recognition applications and texture categorization. This paper investigates the extraction of most discriminative features for different texture images from the “Colored Brodatz” dataset using two types of image contrast measures, as well as using the statistical moments on five bands (red, green, blue, grey, and black). The Euclidean distance measure is used in the matching step to check the similarity degree. The proposed method was tested on 112 classes of textures. The achieved results showed that the proposed method is accurate and fast concerning classification accuracy with low computational complexity. The achieved Recognition Rate (RR) was 100%. [ABSTRACT FROM AUTHOR]

Fluorescence images enhancement is important as it can provide more information for medical diagnosis. In this work, we design three simple yet useful filters based on the combinations of mathematical functions, which are proved to be effective in strengthening the images acquired from the fluorescence microscope. Using these filters, detailed objects can be found in the dark sections of the fluorescence images. In addition, these filters can be used to enhance the low-light image, which provide satisfactory visual information and marginal profile for the blurred objects in the image. Moreover, these filters have been used to enhance the image with high degradation by the Gaussian noise, where clear edge profile can be extracted. Finally, we have shown that these filters can be utilized for the image compression. Compression ratio can be obtained to be 0.9688. This study shows the making of the filters with dual functions for the image enhancement and the image compression. Our designed filters are showing the potentials in the field of biomedical imaging and pattern identification.

The Wiener filter is widely used in image de-noising. It is used to reduce Gaussian noise. Although the Wiener filter removes noise from the image, it causes a loss of edge detail information, resulting in blurring of the image. The edge details are considered high-frequency components. The Wiener filter is unable to reconstruct these components. In this paper, the proposed filter based on the Wiener filter and the high-boost filter for medical images is presented. The proposed filter is applied to the degraded image. First, using Fourier Transformation, the degraded image and the high boost filter are converted in the frequency domain. Secondly, the wiener filter is applied to the image along with the high boost filter. Thirdly, the deconvolution process is achieved on the image with the high boost filter. Finally, to reconstruct the sharper image in the spatial domain, the inverse of the Fourier transformation is applied. The proposed filter works to suppress the additive noise at the same time. It can keep the image's edge details. Some focus operators are used, which are image contrast, gradient energy, histogram entropy, and spatial frequency, in order to test the proposed algorithm. Experimental results showed that the proposed filter gives good results compared with the traditional filters for medical images, especially dark images. [ABSTRACT FROM AUTHOR]

Soil amendments (e.g., compost) require uniform incorporation in the soil profile to benefit plants. However, machines may not mix them uniformly throughout the upper soil layer commonly explored by plant roots. The study focuses on using image texture analysis to determine the level of mixing uniformity in the soil following the passage of two kinds of harrows. A 12.3-megapixel DX-format digital camera acquired images of soil/expanded polystyrene (in the laboratory) and soil/compost mixtures (in field conditions). In the laboratory, pictures captured the soil before and during the simulated progressive mixing of expanded polystyrene particles. In field conditions, images captured the exposed superficial horizons of compost-amended soil after the passage of a combined spike-tooth–disc harrow and a disc harrow. Image texture analysis based on the gray-level co-occurrence matrix calculated the sums of dissimilarity, contrast, entropy, and uniformity metrics. In the laboratory conditions, the progressive mixing resulted in increased image dissimilarity (from 1.15 ± 0.74 × 106 to 1.65 ± 0.52 × 106) and contrast values (from 2.69 ± 2.06 × 106 to 5.67 ± × 1.93 106), almost constant entropy (3.50 ± 0.25 × 106), and decreased image uniformity (from 6.65 ± 0.31 × 105 to 4.49 ± 1.36 × 105). Using a tooth-disc harrow in the open field resulted in higher dissimilarity, contrast, entropy (+73.3%, +62.8%, +16.3%), and lower image uniformity (−50.6%) than the disc harrow, suggesting enhanced mixing in the superficial layer. [ABSTRACT FROM AUTHOR]

Visual-analytics-guided systems are replacing human efforts today. In many applications, movement in off-road terrain is required. Considering the need to negotiate various soft ground and desertic conditions, the beaten tracks of leading vehicles considered to be safe and suitable for guiding are used in such operations. During night, often, these tracks pass through low-contrast conditions posing difficulty in their identification. The maximization of track contrast is therefore desired. Many contrast enhancement techniques exist but their effectiveness varies as per the surrounding. Other than conventional techniques, the role of texture too becomes important for enhancing the differentiable track contrast. Gray-level co-occurrence matrix (GLCM)-based statistic measures are used here to evaluate the track texture. These measures are seen to improve the contrast of vehicle tracks significantly. A track-index-based technique is proposed to sort various images as per their effectiveness in increasing the track contrast. Different forms of track indices are proposed and compared. The proposed track index is seen as effective in sorting 88.8% of contrast images correctly. The proposed technique of creating and sorting images based on the contrast level is seen as a useful tool for improved fidelity in many difficult situations for making the off-road operations sustainable. [ABSTRACT FROM AUTHOR]

Image contrast plays a pivotal role in the realm of digital imaging and computer vision, significantly influencing the visual quality and subsequent interpretation of images. Evaluating and quantifying this contrast has emerged as a critical need in a wide spectrum of applications, including medical imaging, remote sensing, and digital photography, among others. This paper offers a comprehensive review of various metrics available for the evaluation of image contrast, focusing on their underlying formulas, interpretations, advantages, disadvantages, and pertinent usage scenarios. The study compares metrics from histogram-based, spatial frequency-based, and statistical perspectives. It explores the computational complexity, accuracy, and robustness of these metrics, including their sensitivity to noise and other image degradations. Further, we discuss the real-world applications of these metrics in the domains of image enhancement, image quality assessment, and image compression. We also outline current challenges and propose future research directions for developing more robust and versatile contrast metrics. Our findings underscore the importance of an appropriate choice of contrast metric for effective image analysis and processing in various application settings. [ABSTRACT FROM AUTHOR]

In order to meet the requirements of target detection at different distances in infrared polarization detection, a transmission-type long-wave infrared polarization zoom optical system is designed, can zoom in 18–90 mm and the wavelength range is 8–14 μm. The spatial resolution is 0.18–0.9 mrad, and the machining and assembly errors are analyzed. Based on BRDF and Stokes vector model, aluminum is spontaneous emission, and reflected emission characteristics under specific conditions are simulated and analyzed. Infrared polarization imaging and island imaging experiments verify the unique advantages of infrared polarization technology in distinguishing natural and manufactured objects, metal and non-metal, and high-temperature object recognition. The changing trend of contrast between infrared intensity image and polarization image with solar altitude angle is explored, providing theoretical support for developing an infrared photoelectric detection field.

High-resolution imaging of Cu/low-k on-chip interconnect stacks in advanced microelectronic products is demonstrated using full-field transmission X-ray microscopy (TXM). The comparison of two lens-based laboratory X-ray microscopes that are operated at two different photon energies, 8.0 keV and 9.2 keV, shows a contrast enhancement for imaging of copper nanostructures embedded in insulating organosilicate glass of a factor of 5 if 9.2 keV photons are used. Photons with this energy (Ga-Kα radiation) are generated from a Ga-containing target of a laboratory X-ray source applying the liquid-metal-jet technology. The 5 times higher contrast compared to the use of Cu-Kα radiation (8.0 keV photon energy) from a rotating anode X-ray source is caused by the fact that the energy of the Ga-Kα emission line is slightly higher than that of the Cu-K absorption edge (9.0 keV photon energy). The use of Ga-Kα radiation is of particular advantage for imaging of copper interconnects with dimensions from several 100 nm down to several 10 nm in a Cu/SiO2 or Cu/low-k backend-of-line stack. Physical failure analysis and reliability engineering in the semiconductor industry will benefit from high-contrast X-ray images of sub-μm copper structures in microchips.

Abstract Random lasers with low spatial coherence have important potential applications in speckle‐free imaging and displaying. Here, an angular spectra (AS) tunable random laser is proposed through directly coupling a microcavity with a commercial optical fiber. The local in‐plane AS distributions of the random lasing can be separately tuned by selectively using coupling filtering, free transmission, and intensity modulation. The obtained random lasing has the characteristics of non‐polarization and ring AS with distribution tunability. The unique properties endow the lasing as a promising illumination source for biological imaging. An excellent image with speckle‐free and high contrast is thus achieved with a maximal contrast improvement factor of 638% relative to that under the common white lighting. The results indicate that the designed AS‐tunable random laser has great application values in the fields of biological imaging, display, integration optics, and optical physics.

Color consistency optimization for multiple images is a challenging task in remote sensing and computer vision. To ensure that the visual quality of corrected images is satisfactory, not only should the color discrepancies between multiple images be invisible but also the contrast of individual images should be visually appealing. Most color correction approaches focus on eliminating drastic color discrepancies, but ignore the problem of image contrast enhancement. Some color correction approaches even tend to degrade the image contrast to ensure that the image tones are consistent especially when the contrast of input images is low. To solve this problem, we present a contrast-aware color consistency correction approach in this article. We attempt to eliminate the drastic color differences and enhance the contrast of input images simultaneously. We creatively integrate the problems of color consistency correction and image contrast enhancement into the same global energy optimization framework, and we also design a special cost function to minimize the color discrepancies and enhance the image contrast using the original color information. Thus, although the contrast of input images is low, our approach can still generate the corrected images with consistent tones and visually appealing contrast. At last, we select several challenging datasets to evaluate our approach. The experimental results visually and quantitatively demonstrate the effectiveness and superiority of the proposed contrast-aware color consistency correction approach. The results also demonstrate that our approach significantly outperforms the existing approaches, especially when the contrast of the input images is low.

Light-sheet fluorescence microscopy (LSFM) is a kind of volumetric imaging methodology suited for long term living specimens at high temporal-spatial resolution. A single Airy beam (SAB) light-sheet can extend the field of view of Light-sheet fluorescence microscopy benefiting from its non-diffracting nature, but at the cost of out-of-focus background and low imaging contrast caused by side lobes illumination. Here, we propose a method to generate a sort of multiple Airy beams (MAB), which are linearly superimposed of multiple single Airy beams with different scale factors. Compared to the SAB light-sheet, the energy of the multiple Airy beams light-sheet is more concentrated on the focal plane of the detection objective, which can improve the imaging contrast and decrease the photodamage effect. Furthermore, we combined the complementary beam subtraction (CBS) strategy to increase the axial resolution, termed as multiple Airy beams-complementary beam subtraction method, which enables the axial resolution of 1.2 μm while keeping the field of view of 450 μm × 450 μm. The effectiveness of the method is demonstrated by imaging of fluorescent beads and aspergillus conidiophores.

To suppress the noise and sidelobe of photoacoustic images, a method is proposed combined with spatial coherence and polarity coherence. In this method, PA signals are delayed, multiplied, then performed polarity coherence, and finally summed. The polarity of delayed-and-multiplied signals rather than the amplitude is considered in polarity coherence operation. The polarity coherence factor is calculated based on the standard deviation of the polarity. Then, the factor as weights is applied to the coherent sum output after spatial autocorrelation to finally obtain the image. The simulated and experimental results prove that the noise level can be effectively suppressed due to its relatively low polarity coherence factor. Compared with the delay-and-sum method, the quantitative results in simulations show that the image contrast and full-width at half-maximum of the proposed method increase by about 227.0 % and 56.5 % when the signal-to-noise ratio of the raw signal is 0 dB, respectively. Besides achieving a better image contrast, this method obtains improvements in sidelobe attenuation and has a narrow main lobe.

Laser speckle contrast imaging (LSCI) is a real-time, full-field, non-contact optical imaging technique that has been widely used in blood flow imaging. However, its practical applications are limited due to its low signal-to-noise ratio (SNR) and low image contrast. In this study, a fusion denoising algorithm based on homomorphic transform and block-matching and 3D transform-domain collaborative filtering algorithm is proposed to reduce noise and improve image contrast. The reliability and applicability of the proposed method were evaluated by a phantom experiment and two in vivo experiments. The results show that the proposed algorithm can effectively remove the noise and enhance the image contrast. Consequently, the SNR is increased, the dynamic range of LSCI is expanded, and the estimation accuracy of blood flow is improved. [ABSTRACT FROM AUTHOR]

The protection of information against electromagnetic penetration is one of the most important aspects related to the protection of information against its non-invasive acquisition. Compared to the activities of cybercriminals, the use of electromagnetic emissions in the electromagnetic infiltration process does not leave any traces of activity, and the owner of the information is not aware of its loss. The most common activities of electromagnetic eavesdropping are related to the infiltration of emission sources, graphically revealing the processing of information using both analog and digital methods. This allows for the presentation of reconstructed data in the form of images. Correct display of the acquired information requires knowledge of raster parameters such as line length and the number of lines building the reconstructed image. Due to the lack of direct access to the intercepted device, knowledge in this field does not allow for the correct determination of the aforementioned parameters, and thus, for recreating an image that would contain legible and understandable data. Additionally, incorrect values of the parameters result in failure of further processing of the obtained image, e.g., by using a coherent summation of images. Therefore, it is necessary to propose a solution that will allow not so much to roughly define the raster parameters but to estimate them precisely. Moreover, it should enable the automation of the process after the implementation of an appropriate algorithm. The article proposes an algorithm for estimating the line length of the reconstructed image. The raster parameter estimated with the use of the algorithm allows for summarizing images several dozen times with a significant improvement in the image quality and readability of the data contained in it. The image summation algorithm is very often used as one of the main image processing methods in the electromagnetic infiltration process. Incorrect raster parameters often make coherent summation useless. The proposed algorithm for estimating the line length of the reconstructed image uses three methods of determining the line length of the image for a given accuracy. At the same time, criteria were indicated that must be met to determine the correct length of the image line for the assumed accuracy of estimation. Obtained results confirmed that the proposed methods and criteria are effective in the process of electromagnetic infiltration. These methods allow us to determine the line length of reconstructed images with accuracy up to 10 − 5 . [ABSTRACT FROM AUTHOR]

Analyzing medical images has always been a challenging task because these images are used to observe complex internal structures of the human body. This research work is based on the study of the retinal fundus and magnetic resonance images (MRI) for the analysis of ocular and cerebral abnormalities. Typically, clinical quality images of the eyes and brain have low-varying contrast, making it challenge to diagnose a specific disease. These issues can be overcome, and preprocessing or an image enhancement technique is required to properly enhance images to facilitate postprocessing. In this paper, we propose an iterative algorithm based on the McCann Retinex algorithm for retinal and brain MRI. The foveal avascular zone (FAZ) region of retinal images and the coronal, axial, and sagittal brain images are enhanced during the preprocessing step. The High-Resolution Fundus (HRF) and MR brain Oasis images databases are used, and image contrast and peak signal-to-noise ratio (PSNR) are used to assess the enhancement step parameters. The average PSNR enhancement on images from the Oasis brain MRI database was about 3 dB with an average contrast of 57.4. The average PSNR enhancement of the HRF database images was approximately 2.5 dB with a contrast average of 40 over the database. The proposed method was also validated in the postprocessing steps to observe its impact. A well-segmented image was obtained with an accuracy of 0.953 and 0.0949 on the DRIVE and STARE databases. Brain tumors were detected from the Oasis brain MRI database with an accuracy of 0.97. This method can play an important role in helping medical experts diagnose eye diseases and brain tumors from retinal images and Oasis brain images. [ABSTRACT FROM AUTHOR]

T1 contrasts obtained using short‐TR incoherent steady state gradient echo (GRE) methods are generally suboptimal, to which non‐T1 factors in the signals play a major part. In this work, we proposed an augmented T1‐weighted (aT1W) method to extract the signal ratio between routine GRE T1W and proton density‐weighted signals that effectively removes the non‐T1 effects from the original T1W signals, including proton density, T2* decay, and coil sensitivity. A recently proposed multidimensional integration (MDI) technique was incorporated in the aT1W calculation for better signal‐to‐noise ratio (SNR) performance. For comparison between aT1W and T1W results, Monte Carlo noise analysis was performed via simulation and on scanned data, and region‐of‐interest (ROI) analysis and comparison was performed on the system phantom. For brain scans, the image contrast, noise behavior, and SNR of aT1W images were compared with routine GRE and inversion‐recovery–based T1W images. The proposed aT1W method yielded saliently improved T1 contrasts (potentially > 30% higher contrast‐to‐noise ratio [CNR]) than routine GRE T1W images. Good spatial homogeneity and signal consistency as well as high SNR/CNR were achieved in aT1W images using the MDI technique. For contrast‐enhanced (CE) imaging, aT1W offered stronger post‐CE contrast and better boundary delineation than T1 MPRAGE images while using a shorter scan time. [ABSTRACT FROM AUTHOR]

In this document, we propose an image tone mapping method enhancing the image visibility in outdoor environment. The proposed method improves the outdoor visibility of the displayed image in two aspects: brightness enhancement and content adaptive contrast enhancement. From the experiment results, it is confirmed that the proposed method improves the brightness and the contrast at the same time and enhances outdoor visibility effectively even with the limited dynamic range of the display device. Compared to conventional methods, proposed method has higher flexibility and effectiveness. This method is already utilized on the mobile devices for outdoor visibility enhancement and we expect to apply it to the automotive platforms. [ABSTRACT FROM AUTHOR]

The goal of the studies described in the paper is to find a quantitative assessment that maximally correlates with the subjective assessment of the contrast image quality in the absence of reference image. As a result of the literature analysis, 16 functions were selected that are used for no-refernce image quality assessment: BEGH, BISH, BREN, CMO, CURV, FUS, HELM, EBCM, KURT, LAPD, LAPL, LAPM, LOCC, LOEN, SHAR, WAVS. They all use the arithmetical mean of the local contrast quality. As an alternative to averaging local estimates (since the mean is one of two parameters of the normal distribution), it is proposed to use one of two parameters of the Weibull distribution of the same data – scale or shape.For the experiments, digital images with nonlinear contrast distortion from the available CCID2014 database were used. It contains 15 original images with a size of 768x512 pixels and 655 versions with modified contrast. This database of images contains the average visual quality assessment (Mean Opinion Score, briefly MOS) of each image. Spearman’s rank correlation coefficient was used to determine the correspondence between the visual MOS scores and the studied quantitative measures.As a result of the research, a new quality assessment measure of contrast images in the absence of references is presented. To obtain the estimate, local quality values are calculated by the BREN measure, their set is described by the Weibull distribution, and the scale parameter of the distribution serves as the best numerical estimate of the quality of contrast images. This conclusion is confirmed experimentally, and the proposed measure correlates better than other variants with the subjective assessments of experts.

Soil amendments (e.g., compost) require uniform incorporation in the soil profile to benefit plants. However, machines may not mix them uniformly throughout the upper soil layer commonly explored by plant roots. The study focuses on using image texture analysis to determine the level of mixing uniformity in the soil following the passage of two kinds of harrows. A 12.3-megapixel DX-format digital camera acquired images of soil/expanded polystyrene (in the laboratory) and soil/compost mixtures (in field conditions). In the laboratory, pictures captured the soil before and during the simulated progressive mixing of expanded polystyrene particles. In field conditions, images captured the exposed superficial horizons of compost-amended soil after the passage of a combined spike-tooth–disc harrow and a disc harrow. Image texture analysis based on the gray-level co-occurrence matrix calculated the sums of dissimilarity, contrast, entropy, and uniformity metrics. In the laboratory conditions, the progressive mixing resulted in increased image dissimilarity (from 1.15 ± 0.74 × 106 to 1.65 ± 0.52 × 106) and contrast values (from 2.69 ± 2.06 × 106 to 5.67 ± × 1.93 106), almost constant entropy (3.50 ± 0.25 × 106), and decreased image uniformity (from 6.65 ± 0.31 × 105 to 4.49 ± 1.36 × 105). Using a tooth-disc harrow in the open field resulted in higher dissimilarity, contrast, entropy (+73.3%, +62.8%, +16.3%), and lower image uniformity (−50.6%) than the disc harrow, suggesting enhanced mixing in the superficial layer.

Dynamic friction occurs not only between two contact objects sliding against each other, but also between two relative sliding surfaces several nanometres apart. Many emerging micro- and nano-mechanical systems that promise new applications in sensors or information technology may suffer or benefit from noncontact friction. Herein we demonstrate the distance-dependent friction energy dissipation between the tip and the heterogeneous polymers by the bimodal atomic force microscopy (AFM) method driving the second order flexural and the first order torsional vibration simultaneously. The pull-in problem caused by the attractive force is avoided, and the friction dissipation can be imaged near the surface. The friction dissipation coefficient concept is proposed and three different contact states are determined from phase and energy dissipation curves. Image contrast is enhanced in the intermediate setpoint region. The work offers an effective method for directly detecting the friction dissipation and high resolution images, which overcomes the disadvantages of existing methods such as contact mode AFM or other contact friction and wear measuring instruments. [ABSTRACT FROM AUTHOR]

Objectives: The objective is to standardize the reconstruction parameters for the time-of-flight (TOF) versus non-TOF positron-emission tomography/computed tomography (PET/CT) imaging data and validation of the same in a clinical setting. Methods: The four spheres (10.0/13.0/17.0/22.0 mm) of the PET phantom (NEMA IQ Nu 2-2001) were filled with four times higher activity of [18F]-NaF than the background (5.3kBq/mL). Imaging (image matrix - 128 x 128 x 47, 2 min, 3D model) was done using two different (TOF/non-TOF) PET scanners. Phantom data were reconstructed in TOF and non-TOF modes for lutetium-yttrium oxyorthosilicate and non-TOF mode for bismuth germanate-based PET scanners. The reconstructed data (by varying iteration and subsets) that provided the best image contrast and signal-to-noise ratio (SNR) were evaluated. The whole-body [18F]-fludeoxyglucose (FDG) PET/CT scans (7-8 frames; 2.0 min/frame) in 16 lymphoma patients were acquired at 60 min after injecting the radioactivity (370.0-444.0 MBq of [18F]-FDG. The clinical PET/CT data were reconstructed using phantom-derived reconstruction parameters and evaluated for image contrast and SNR of the detected lesions. Results: TOF reconstruction at second iteration provided significantly (P ≤ 0.02) higher SNR (20.7) and contrast (contrast recovery coefficient/background variability = 3.21) for the smallest hot lesions (10.0 mm) in the phantom than the non-TOF system. Similarly, in patient data analysis for the selected FDG avid lesions, the SNR values were significantly (P = 0.02) higher (13.3 ± 6.49) in TOF than (11 ± 6.48) in non-TOF system. Further, the small (≤10.0 mm) lesions were seen more distinctly in TOF system. Conclusion: It is thus observed that TOF reconstruction converged faster than the non-TOF, and the applicability of the same may impact the image quality and interpretation in the clinical PET data. The validation of the phantom-based experimental reconstruction parameters to clinical PET imaging data is highly warranted. [ABSTRACT FROM AUTHOR]

The process of dynamic spectral processing of optical radiation in the active electro-optical system that provides enhancement of the contrast of the image target has been experimentally researched. A routine of experiment and a diagram of an experimental setup have been developed. The sources of optical radiation in the transmitting part of the active electro-optical system were three semiconductor lasers operating in the ranges of the red, green, and blue spectral regions. Absorption optical filters were used in the experiment as the elements simulating the spectral properties of the reflecting surfaces of the target and the background. To enhance the contrast of the target image, the spectral composition of the laser radiation is formed to provide maximum suppression of the background signal with minimum attenuation of the optical signal of the object. When forming the spectral density of the laser radiation intensity, a priori information about the spectral characteristics of the target and the background has been used. The results obtained in the course of the experiment confirm the possibility to separate the target signal from the background interferences due to using the dynamic spectral processing of optical radiation in the active electro-optical system. [ABSTRACT FROM AUTHOR]

Using kilovoltage cone-beam computed tomography (kV-CBCT) and heavy-atom radiosensitizers in image-guided radiotherapy (IGRT) can provide numerous benefits, such as image contrast enhancement in radiation dose delivery. However, the increased use of kV-CBCT for daily imaging procedures may inevitably deposit certain amount of radiation dose to the patient, especially when nanoparticles used as radiosensitizers are involved. In this study, we use Monte Carlo simulation to evaluate the imaging dose escalation due to nanoparticle addition with varying nanoparticle material, nanoparticle concentration and photon beam energy. A phantom was used to determine the relationships between the imaging dose enhancement ratios (IDERs) and different concentrations (3–40 mg/ml) of gold (Au), platinum (Pt), iodine (I), silver (Ag) and iron oxide (Fe2O3) nanoparticles, under the delivery of 120–140 kVp photon beams from the CBCT. It is found that gold and platinum nanoparticles of 40 mg/ml concentration had the highest IDER (~1.6) under the 120 kVp photon beam. This nanoparticle addition resulted in a 0.63% increase of imaging dose based on a typical dose prescription of 200 cGy per fraction in radiotherapy, and is within the standard uncertainty of ±5% in radiation dose delivery. This study proves that the incorporation of higher concentration nanoparticles under lower photon beam energy could increase the imaging dose. The results from this study can enable us to understand more about the incorporation of heavy-atom nanoparticles in IGRT systems.

Image enhancement is commonly used in digital image processing applications. Through image enhancement, the features of the target object are enhanced to make it easier to identify. In order to realize image enhancement, a neural network with a trapezoidal convolution kernel is proposed in this paper. First, weak contrast images are generated using the images in SIDD, DND and RENOIR, which are public datasets used for image denoising. On this basis, pixel distribution characteristics of the R, G and B channels of the weak contrast images are analyzed, and the histogram distribution of the images is given, which can be used to determine the size of the network convolution kernels. Then, a multi-layer convolution neural network is constructed, which uses the original image as an input and outputs the noise map. This network includes convolution kernels of different sizes for the three channels of the original images, and the convolution kernel size is determined by calculating the mean square deviation of the pixels of the corresponding channel. The proposed algorithm provides visually pleasing contrast enhancement. In this paper, a public dataset for image enhancement and actual captured images are separately assessed, both the contrast experiment and ablation experiment results show that the algorithm proposed in this paper can achieve a higher Peak Signal to Noise Ratio (PSNR) and a higher Structural Similarity Index (SSIM) than other image enhancement algorithms.

During image acquisition, nonuniform illumination regions are produced due to several factors, such as improper environment lighting and inappropriate capturing device setting. Applying contrast enhancement methods with the same enhancement concept to the whole image can over enhance or under enhance nonuniform illumination image. Thus, different and specific enhancement concepts should be applied to different regions in nonuniform illumination image. This concept requires identification of those different regions. Almost all existing methods that introduced the region determination process can only detect two different regions, namely, dark and bright, which inadequately represent the real exposure condition because the methods only consider intensity criteria to determine the regions. For this problem, a new method used for the accurate detection of nonuniform illumination regions is proposed. Different illumination levels affect not only the intensity but also the details in an image. Thus, three image attributes, namely, intensity, entropy and contrast, which are evaluated locally in detecting the regions, must be considered. For the detection to be on par with that in humans, the three attributes are combined with a rule-based method for the identification of illumination regions. Experimental results involving evaluation from research experts demonstrate that the proposed method qualitatively detects different illumination regions (i.e., over-exposed, well-exposed and under-exposed) in a nonuniform illumination image more accurate than the state-of-the-art methods.

Subsurface detection capability of bimodal atomic force microscopy (AFM) was investigated using the buried microcavity as a reference sample, prepared by partially covering a piece of highly oriented pyrolytic graphite (HOPG) flake with different thickness on a piece of a cleaned CD-R disk substrate. This capability can be manifested as the image contrast between the locations with and without the buried microcavities. The theoretical and experimental results demonstrated that the image contrast is significantly affected by the critical parameters, including the second eigenmode amplitude and frequency as well as local structural and mechanical properties of the sample itself. Specifically, improper parameter settings generally lead to incorrect identification of the buried microcavity due to the contrast reduction, contrast reversal and even disappearance. For accurate detection, the second eigenmode amplitude should be as small as possible on the premise of satisfying the signal-to-noise ratio and second eigenmode frequency should be close to the resonance frequency of the cantilever. In addition, the detectable depth is closely related to microcavity dimension (thickness and width) of the HOPG flake and local stiffness of the sample. These results would be helpful for further understanding of the detection mechanism of bimodal AFM and facilitating its application in nano-characterization of subsurface structures, such as the micro-/nano- channels to direct the flow of liquids in lab-on-a-chip devices., (© 2024 IOP Publishing Ltd.)

Medical image fusion technology makes clinical diagnosis and treatment more accurate. This technique can solve the existing problem that single mode medical images conveying insufficient information. Therefore, the key to this technology is to retain as much as possible information in the original medical image of multiple modes. However, the existing methods often lose source image detail with a low contrast and cause color distortion. This article proposed a novel multi‐modal medical image fusion framework. Our framework has four key steps. First, extracting the super‐resolution images from anatomical images via a deep neural network is performed. Second, decomposing the source images into detail‐enhanced approximate and residual images, and then processing by local Laplacian filtering. Third, a convolution neural network is used to complete the mapping of the source image to the feature map and the local energy‐based strategy is used to integrate the coefficients. Finally, the inversed local Laplacian pyramid is adopted to reconstruct the fused image. The experimental results prove that the fused image via the proposed method has the characteristics of high contrast, high brightness, and high color saturation and great advantages in retaining the color and structural information. [ABSTRACT FROM AUTHOR]