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Steel wire rope usually works in harsh environments, making it prone to damage during frequent use. Magnetic flux leakage testing is an important way of non-destructive testing, preventing some major accidents of hoist equipment by identifying the damage to steel wire ropes. Whereas, the harsh environment usually generates noise and results in difficulty in extracting the damage features of the magnetic flux leakage signal, which makes it hard to identify the damage. The fast Walsh-Hadamard transform is widely used in signal processing. The denoising effect depends closely on the transform coefficients. If the transformation coefficients can be adaptively retained, better denoising effects can be achieved. Therefore, we propose the adaptive fast Walsh-Hadamard transform to extract the magnetic flux leakage signal of steel wire rope under noise background. Using the cross-correlation co efficient and the similarity of the greyscale histogram as the indexes, the Fast Walsh-Hadamard transform combines the adaptive particle swarm optimisation to adaptively retain the optimal transformation coefficient and then gets the optimal denoising signal. Meanwhile, compared to wavelet denoising methods, the adaptive fast Walsh-Hadamard transform can effectively improve denoising performance in peak-to-peak reductivity and can be successfully used in steel wire rope damage extraction. [ABSTRACT FROM AUTHOR]

The grayscale histogram (GH) is a tool available in some software that allows evaluating the quantity and distribution of the grayscale frequency of certain region studied in an image. In ultrasonography, GH has been applied to assess the echogenicity and echotexture of different organs, revealing clinical applicability. This study makes a comparative analysis of the echogenicity and echotexture of the palmar and plantar digital arteries in healthy horses and mules using the grayscale histogram (GH). It also set out to compare the possible variability between the superficial and deep tunica intima and media (IM) of the vessels evaluated. B-Mode ultrasonography was performed in the longitudinal plane of the lateral and medial palmar and plantar digital arteries in 10 healthy horses and 10 mules. Subsequently, the images were analyzed using the GH tool to acquire the variables Mean (echogenicity) and Standard deviation (StdDev) (ecotexture). It was observed that mules showed higher values of brightness intensity (Mean) than horses. Differences were observed between superficial and deep IM, and the deep wall showed higher echogenicity and heterogeneity in both the equine species and in the mule hybrid. The GH proved to be a viable tool to quantify the echogenicity and echotexture of the walls (superficial and deep) of the palmar and plantar digital arteries of horses and mules. In addition, it allowed to highlight the differences found between animals (horses and mules) and IM (superficial and deep). [ABSTRACT FROM AUTHOR]

Objective: To investigate texture parameters of contrast-enhanced computed tomography (CT) images before and after transarterial chemoembolization (TACE) as a tool for assessing the therapeutic response and survival predication in hepatocellular carcinoma (HCC). Materials and methods: Data of 77 HCC patients who underwent three-phase dynamic contrast-enhanced CT examination within 4 weeks before and 4-8 weeks after TACE were collected and efficacy evaluation was performed according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST) standard. The remission group consisted of 31 patients (12 with complete remission+19 with partial remission), while the non-remission group consisted of 46 patients (27 with stable disease+19 with progressive disease). Full-volume manual delineation of the region of interest (ROI) and texture analysis of the ROI were performed on the CT images using FireVoxel software. Changes in the 48 texture parameters from three-phase CT images before and after TACE were calculated and compared between the two groups. The receiver operating characteristic (ROC) curve and the areas under the curve (AUC) were used to analyze the diagnostic performance of texture parameters. A multifactorial Cox model was used for predicting survival. The C-indices of texture parameter difference values with predictive value, texture features model, and texture features combined with mRECIST in predicting OS were compared with those of mRECIST. Results: A total of 41 changes in texture parameters were statistically significant between the remission and non-remission groups. The receiver operating characteristic (ROC) curve showed that the AUC of changes in the 90th percentile in the arterial phase was the largest at 0.842. When the cut-off value was 70.50, the Youden index was the largest (0.621), and the sensitivity and specificity were 0.710 and 0.911, respectively. Three changes in texture parameters were independent factors associated with patient survival, with a hazard of 0.173, 2.068, and 1.940, respectively. The C-index of the OS predicted by the texture features model was not statistically different from that of the mRECIST (0.695 vs. 0.668, p=0.493). While the C-indices of skewness in the portal venous phase combined with mRECIST (0.729, p=0.015), skewness in the delayed phase combined with mRECIST (0.715, p=0.044), and skewness in both two phases combined with mRECIST (0.728, p=0.017) were statistically different. Conclusion: Changes in the texture parameters of CT images before and after TACE treatment can be used to obtain relevant grayscale histogram parameters for evaluating the early efficacy of TACE in HCC treatment. And the texture analysis combined with mRECIST may be superior to the mRECIST alone in predicting survival in HCC after TACE treatment. [ABSTRACT FROM AUTHOR]

In the monocular visual-inertia mode of ORB-SLAM3, the insufficient excitation obtained by the inertial measurement unit (IMU) will lead to a long system initialization time. Hence, the trajectory can be easily lost and the map creation will not be completed. To solve this problem, a fast map restoration method is proposed in this paper, which adresses the problem of insufficient excitation of IMU. Firstly, the frames before system initialization are quickly tracked using bag-of-words and maximum likelyhood perspective-n-point (MLPNP). Then, the grayscale histogram is used to accelerate the loop closure detection to reduce the time consumption caused by the map restoration. After experimental verification on public datasets, the proposed algorithm can establish a complete map and ensure real-time performance. Compared with the traditional ORB-SLAM3, the accuracy improved by about 47.51% and time efficiency improved by about 55.96%. [ABSTRACT FROM AUTHOR]

Objective: Lung ultrasound (LUS) is a radiation‐free, affordable, and bedside monitoring method that can detect changes in pulmonary aeration before hypoxic damage. However, visual scoring methods of LUS only enable subjective diagnosis. Therefore, quantitative analysis of LUS is necessary for obtaining objective information on pulmonary aeration. Because raw data are not always available in conventional ultrasound systems, Shannon entropy (ShanEn) of information theory without the requirement of raw data is valuable. In this study, we explored the feasibility of ShanEn estimated through grayscale histogram (GSH) analysis of LUS images for the quantification of pulmonary aeration. Methods: Different degrees of pulmonary aeration caused by edema was induced in 32 male New Zealand rabbits intravenously injected with 0.1 mL/kg saline (the control group) and 0.025, 0.05, and 0.1 mL/kg oleic acid (mild, moderate, and severe groups, respectively). In vivo grayscale LUS images were acquired using a commercial point‐of‐care ultrasound system for estimation of GSH and corresponding ShanEn. Both lungs of each rabbit were dissected, weighed, and dried to determine the wet weight‐to‐dry weight ratio (W/D) through gravimetry. Results: The determination coefficients of linear correlations between ShanEn and W/D increased from 0.0487 to 0.7477 with gain and dynamic range (DR). In contrast to visual scoring methods of pulmonary aeration that use median gain and low DR, ShanEn for quantifying pulmonary aeration requires high gain and DR. Conclusion: The current findings indicate that ShanEn estimated through GSH analysis of LUS images acquired using conventional ultrasonic imaging systems has great potential to provide objective information on pulmonary aeration. [ABSTRACT FROM AUTHOR]

Ultrasonic C-scan detection is adopted in this study to compare the connection status of resistance convex weld (RCW) before, during and after fatigue test. Based on the variation of ultrasonic echoes in different connection zones, the connection state can be observed on ultrasonic C-scan images. With the occurrence of fatigue destructive behavior, ultrasonic C-scan image changes, and so does the pixel distribution. The histogram of pixel grayscale distribution can quantitatively evaluate the fatigue limit of stainless steel RCW joint, which provides an effective method to judge the fatigue life in practical engineering application. [ABSTRACT FROM AUTHOR]

• MRI was used to detect clubroot of oilseed rape. • Average sample grayscale histograms of MRI images were extracted and analyzed. • Root architecture parameters were extracted from reconstructed 3D root by MRI images. • Good classification performances of clubroot detection were obtained using MRI. Plant root diseases threat plant growth and eventually cause plant death without proper treatment. It is difficult to diagnose root diseases without digging the roots from the soil, and it is late when the above-ground parts show symptoms under the stress of root diseases. This study used magnetic resonance imaging (MRI) for non-invasive root phenotyping to detect oilseed rape clubroot. MRI images of healthy oilseed rape roots and roots infected by clubroot were obtained. After image preprocessing, average sample grayscale histograms (Avg-SGH) were extracted to build classification models for disease identification using logistic regression (LR), support vector machine (SVM) and random forest (RF). Reconstruction of three-dimensional (3D) root architectures was also conducted. Root architecture parameters were extracted from the reconstructed roots. Analysis of variance (ANOVA) showed that the root architecture parameters differed significantly between healthy and infected roots. RF model using root architecture parameters showed good performances, and the feature importance for clubroot identification was also explored. The overall results showed that MRI could effectively detect clubroot diseases in a non-invasive manner, indicating significant potential for plant root phenotyping. [ABSTRACT FROM AUTHOR]

Highlights • Chlorophyll fluorescence imaging can be used to evaluate chilling stress. • F, Y(Ⅱ), Y(NPQ), Y(NO), qP, qL show good spatial heterogeneity in chilling stress of leaves. • Grayscale histograms and texture features are good indicators for detecting chilling stress. Abstract The effect of chilling injury on leaves was studied by chlorophyll fluorescence imaging, which was mainly investigated from spatial heterogeneity, histogram distribution and texture features of chlorophyll fluorescence grayscale images, as a means to detect the impact of chilling injury. The fluorescence images used in the experiment were the gray images acquired by Imaging-Pam under dark adaptation. Firstly, the images of fluorescence parameters Fo, F, Fm, Fm', Fv/Fm, Y (II), Y (NPQ), Y (NO), NPQ/4, qN, qP, qL and their respective heterogeneity curves were analyzed, in which the chilling injury in the parameter image of F, Y(II), Y(NPQ), Y(NO), qP, qL exhibited good spatial heterogeneity. With the impact of low temperature, F value raised while susceptible to leaf vein, Y (NO) continued to rise but insensitive to the initial stage of chilling injury, Y (NPQ) increased first and then decreased, qP and qL declined rapidly only sensitive to leaf vein, however Y (II) not only fell continuously but was sensitive to initial cold damage and was not affected by leaf veins. Secondly, the histogram of the Y (II) fluorescent grayscale image was analyzed. In the experiment, the Y (II) data shifted to the left, when the leaf suffered cold damage, and the number of peaks changed from one to two. Finally, by calculating the mean and standard deviation of the gray level co-occurrence matrices ASM, ENT, INE, COR, it is found that the energy values and the correlation values on the Y (II) grayscale map of the leaf gradually reduced, and the entropy and inertia expanded. The results of this study indicate that: (i) chlorophyll fluorescence imaging is a useful technique to evaluate cold stress in tomato leaves; (ii) F, Y(Ⅱ), Y(NPQ), Y(NO), qP, qL show good spatial heterogeneity in chilling stress of leaves ; (iii) Histogram and texture features of gray image are good indicators for evaluating chilling damage. Fluorescence imaging can be used for non-destructive diagnosis of plant chilling injury, which has good development prospects. [ABSTRACT FROM AUTHOR]

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Introduction/background: To evaluate cases of surgically resected pulmonary adenocarcinoma (Ad) with heterogenous ground-glass nodules (HGGNs) or part-solid nodules (PSNs) and to clarify the differences between them, and between invasive adenocarcinoma (IVA) and minimally invasive adenocarcinoma (MIA) + adenocarcinoma in situ (AIS) using grayscale histogram analysis of thin-section computed tomography (TSCT)., Materials and Methods: 241 patients with pulmonary Ad were retrospectively classified into HGGNs and PSNs on TSCT by three thoracic radiologists. Sixty HGGNs were classified into 17 IVAs, 26 MIAs, and 17 AISs. 181 PSNs were classified into 114 IVAs, 55 MIAs, and 12 AISs., Results: We found significant differences in area (P = 0.0024), relative size of solid component (P <0.0001), circumference (P <0.0001), mean CT value (P <0.0001), standard deviation of the CT value (P <0.0001), maximum CT value (P <0.0001), skewness (P <0.0001), kurtosis (P <0.0001), and entropy (P <0.0001) between HGGNs and PSNs. In HGGNs, we found significant differences in relative size of solid component (P <0.0001), mean CT value (P = 0.0005), standard deviation of CT value (P = 0.0071), maximum CT value (P = 0.0237), and skewness (P = 0.0027) between IVAs and MIA+AIS lesions. In PSNs, we found significant differences in area (P = 0.0029), relative size of solid component (P = 0.0003), circumference (P = 0.0004), mean CT value (P = 0.0011), skewness (P = 0.0009), and entropy (P = 0.0002) between IVAs and the MIA+AIS lesions., Conclusion: Quantitative evaluations using grayscale histogram analysis can clearly distinguish between HGGNs and PSNs, and may be useful for estimating the pathology of such lesions., Competing Interests: Disclosure The authors have stated that they have no conflicts of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The development of a Virtual Lab to perform experiments on histogram-based binarization of grey-leveled images is reported. With the aim of automatizing the binarization process, a Heuristic Binarization Threshold is introduced. Once the histogram of a grayscale input image is obtained, the module calculates a Heuristic Threshold by taking the weighted average of the foreground grey levels of the image. Next those pixels in input image whose grey levels are above this threshold are highlighted. Although still not experimentally optimum, this heuristic threshold provides a first approximation towards automatic binarization of greyscale images.

Objective: To investigate texture parameters of contrast-enhanced computed tomography (CT) images before and after transarterial chemoembolization (TACE) as a tool for assessing the therapeutic response and survival predication in hepatocellular carcinoma (HCC)., Materials and Methods: Data of 77 HCC patients who underwent three-phase dynamic contrast-enhanced CT examination within 4 weeks before and 4-8 weeks after TACE were collected and efficacy evaluation was performed according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST) standard. The remission group consisted of 31 patients (12 with complete remission+19 with partial remission), while the non-remission group consisted of 46 patients (27 with stable disease+19 with progressive disease). Full-volume manual delineation of the region of interest (ROI) and texture analysis of the ROI were performed on the CT images using FireVoxel software. Changes in the 48 texture parameters from three-phase CT images before and after TACE were calculated and compared between the two groups. The receiver operating characteristic (ROC) curve and the areas under the curve (AUC) were used to analyze the diagnostic performance of texture parameters. A multifactorial Cox model was used for predicting survival. The C-indices of texture parameter difference values with predictive value, texture features model, and texture features combined with mRECIST in predicting OS were compared with those of mRECIST., Results: A total of 41 changes in texture parameters were statistically significant between the remission and non-remission groups. The receiver operating characteristic (ROC) curve showed that the AUC of changes in the 90th percentile in the arterial phase was the largest at 0.842. When the cut-off value was 70.50, the Youden index was the largest (0.621), and the sensitivity and specificity were 0.710 and 0.911, respectively. Three changes in texture parameters were independent factors associated with patient survival, with a hazard of 0.173, 2.068, and 1.940, respectively. The C-index of the OS predicted by the texture features model was not statistically different from that of the mRECIST (0.695 vs. 0.668, p=0.493). While the C-indices of skewness in the portal venous phase combined with mRECIST (0.729, p=0.015), skewness in the delayed phase combined with mRECIST (0.715, p=0.044), and skewness in both two phases combined with mRECIST (0.728, p=0.017) were statistically different., Conclusion: Changes in the texture parameters of CT images before and after TACE treatment can be used to obtain relevant grayscale histogram parameters for evaluating the early efficacy of TACE in HCC treatment. And the texture analysis combined with mRECIST may be superior to the mRECIST alone in predicting survival in HCC after TACE treatment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Zhou, Lv, Hu, Luo, Li, Zhu and Hai.)

Objective: We explored a method for the quantitative sonographic analysis of myometrial texture using computer-aided image analysis software to assess outcomes following treatment with gonadotrophin-releasing hormone (GnRH) agonist for adenomyosis in women with infertility., Method: Data for patients with ultrasound images of the myometrium obtained at Taipei Medical University Hospital from 1 September 2018 to 5 April 5 2019 were analyzed. Only 10 patients with 20 ultrasound images matched the eligibility criteria. The images were divided into pre-treatment (n = 10) and post-treatment images (n = 10) and quantitative grayscale histograms were obtained from the ultrasound images using publicly available ImageJ computer-aided image analysis software. We analyzed the differences between the pre- and post-treatment images using the Mann-Whitney test and compared the results with outcomes assessed by serum CA-125 levels., Results: Image analysis of the grayscale histograms revealed significant differences between before and after treatment. The classification of the myometrium pre-treatment and post-treatment was similar using CA-125 and histogram grayscale analysis., Conclusion: Computer-aided image analysis of grayscale histograms of the myometrium obtained from ultrasound images is an alternative method for assessing myometrial conditions after GnRH agonist treatment in patients with adenomyosis.

ABSTRACT: Visual inspection of ultrasound examination for assessment of echogenicity and echotexture of blood vessel tissues is a technique routinely used in medical practice in humans. However, simple visual inspection can lead to poor quality diagnoses and errors. The use of grayscale histogram (GSH) analysis has proved to be an efficient technique to quantify the region of interest, allowing minimization of image interpretation errors. This study aimed to evaluate and compare the echogenicity and echotexture of the walls of the common carotid arteries of healthy female horses and mules using the GSH technique and correlate them with age, body mass, and vessel diameters. B-mode ultrasound examinations were performed in the left and right common carotid arteries in three regions (cranial, middle, and caudal) in 11 horses and 11 healthy mules. The GSH of the animals showed heterogeneous walls, but did not differentiate statistically between female horses and mules. The Mean variable of the middle right, middle left and caudal right sides showed differences, more significant in the mules. On the middle right side, the Min variable was different, higher in the mules. On the middle and caudal left side, the variables Max and Mode showed higher values in the mules. For the mules, the age factor presented negative correlation with the Mean, Mode,, Mode(Count), and Mode(Count)/Count(%) variables, and the body mass factor presented negative correlation with the Mode, Mean and Max variables. For the female horses, the body mass factor showed positive correlation with the Mean and Mode variables. Echogenicity of the carotid artery walls differed between female horses and mules, whereas echotexture was heterogeneous and statistically similar among the animals. The age and body mass factors inversely influenced the echogenicity of the mules, but were not significant in the female horses, in which only the body mass factor positively influenced echogenicity.