Maximum Pixel Value Research Articles

Local tone mapping algorithm and hardware implementation

A novel tone mapping algorithm and hardware implementation for displaying wide dynamic range (WDR) images are proposed. The algorithm processes WDR images in a pixel-by-pixel fashion in the logarithmic domain, and it uses the block-interpolated minimum and maximum pixel values. The hardware implementation can achieve real-time processing of WDR images and is resource-efficient. Experimental results show that the proposed algorithm and hardware implementation can produce images with good brightness and high contrast.

Laser-based on-line machine vision detection for longitudinal rip of conveyor belt

Conveyor belts are widely used in mines, power plants, ports to transfer lump materials or products. They are prone to longitudinal rip in operation, which generally results in a stoppage of production, even causes belt break or longitudinal rip accidents for lacking the detection and treatment in time. It has long been recognized that a conveyor belt monitoring system for early detection of longitudinal rip is desirable. Based on the line laser detection technology, an on-line detection method is investigated to accomplish conveyor belt longitudinal rip detection rapidly and accurately, and the monitoring system utilizing machine vision technology is designed in this paper. A red line laser stripe projects on the surface of conveyor belt, and the image obtained by the corresponding CMOS camera is processed and analyzed to judge whether there is a rip on the belt surface or not. Firstly, the red stripe region of interest is segmented. Then, the skeleton representation of the stripe center and the binary image are obtained by maximum pixel value method. And the abnormal pixels, which correspond to the rip position, are detected by the neighborhood search method using the difference algorithm and the curvature method. Finally, the fault region is marked. Experimental results show that the proposed method is fast and high precise. This on-line detection method and system can effectively resolve the problem of conveyor belt longitudinal rip detection, and can be used during production hours with a full conveyor load.

Qualitative and quantitative ultrasound attributes of maternal-foetal structures in pregnant ewes.

The aim of this study was to examine foetal organs and placental tissue to establish a correlation between the changes in the composition of these structures associated with their maturation and the ultrasonographic characteristics of the images. Twenty-four pregnant ewes were included in the study. Ultrasonography assessments were performed in B-mode, from the ninth gestational week until parturition. The lungs, liver and kidneys of foetuses and placentomes were located in transverse and longitudinal sections to evaluate the echogenicity (hypoechoic, isoechoic, hyperechoic or mixed) and echotexture (homogeneous and heterogeneous) of the tissues of interest. For quantitative evaluation of the ultrasonographic characteristics, it was performed a computerized image analysis using a commercial software (Image ProPlus® ). Mean numerical pixel values (NPVs), pixel heterogeneity (standard deviation of NPVs) and minimum and maximum pixel values were measured by selecting five circular regions of interest in each assessed tissue. All evaluated tissues presented significant variations in the NPVs, except for the liver. Pulmonary NPVmean, NPVmin and NPVmax decreased gradually through gestational weeks. The renal parameters gradually decreased with the advancement of the gestational weeks until the 17th week and later stabilized. The placentome NPVmean, NPVmin and NPVmax decreased gradually over the course of weeks. The hepatic tissue did not show echogenicity and echotexture variations and presented medium echogenicity and homogeneous echotexture throughout the experimental period. It was concluded that pixels numerical evaluation of maternal-foetal tissues was applicable and allowed the identification of quantitative ultrasonographic characteristics showing changes in echogenicity related to gestational age.

P1.14-016 Assessing the Feasibility of FLT-PET for Evaluation of Non-Small Cell Lung Cancer (NSCLC) Treated with Stereotactic Body Radiotherapy (SBRT)

Distinguishing fibrosis from tumor recurrence following lung SBRT remains a clinical challenge since CT has poor sensitivity and specificity for detecting recurrence. 18F-Fluoro-L-thymidine-PET (FLT-PET) uptake correlates with cell proliferation. The purpose of this study is to investigate the feasibility of FLT-PET as an imaging biomarker for lung SBRT response assessment. In this prospective study, three groups were included: 1) newly-diagnosed biopsy-proven NSCLC pre-SBRT, 2) established post-SBRT mass-like fibrosis on serial follow-up CT scans by co-investigators’ consensus, and 3) biopsy-proven locally-recurrent NSCLC after SBRT. Non-gated, helical gated (3D-CT/4D-PET) and phase-matched (4D-CT/4D-PET) FLT-PET images were obtained. Group-1 underwent fluorodeoxyglucose (FDG)-PET scan according to clinical guidelines. FLT uptake was measured by SUV95 and SUV50 (95% and 50% of maximum pixel value plus average background value, respectively), SUV2Dpeak and SUV3Dpeak (1cm diameter circular or spherical around region of interest, respectively), SUVmean and SUVmax. Descriptive statistics were gathered. Kolmogorov–Smirnov test was used to determine normality. Statistical significance was reported using student’s t-test. 27 patients were included, with 19 primary tumors (group-1), 12 established fibrosis (group-2) and 1 recurrence (group-3). In group-1, 16 tumors were T1. Group-1, mean FDG-PET SUVmax, SUV95, SUV50, SUV2Dpeak, SUV3Dpeak and SUVmean were 7.40, 5.88, 2.39, 5.59, 6.02 and 2.78, respectively. Mean FLT-PET values for group-1 were 3.43, 2.84, 1.71, 2.9, 2.82 and 1.78, respectively. Group-2 SBRT dose was either 48Gy in 4 fractions (83%) or 60Gy in 8 fractions. Median time from radiation to FLT-PET scan in group-2 was 19.5 months (5.8-83.8mos). The patient in group-3 had SUV50, SUV95, SUV2Dpeak, SUV3Dpeak, SUVmean and SUVmax of 2.27, 3.85, 6.37, 6.05, 2.39 and 7.64, respectively. Mean FLT-PET SUVmax for groups 1 and 2 was significantly different (p=0.03) at 3.42(1.14-7.04) and 2.34(1.23-4.35) respectively. Similarly, mean (range) of SUV50, SUV95 and SUVmean for group-1 was 1.8(0.74-3.43), 2.97(1.03-5.83), 1.87(0.73-3.44), and for group-2 was 1.22(0.81-2.26), 1.85(1.13-3.8) and 1.25(0.83-2.39), respectively (p<0.01, <0.01 and <0.01). There was no statistically-significant difference between SUV2Dpeak and SUV3Dpeak between groups 1 and 2, with a mean of 2.97(0.99-6.30) and 2.91(0.90-6.11) for group-1 and 2.10(1.11-3.91) and 2.03(1.00-3.86) for group-2 (p=0.06 and 0.06), respectively. There was no statistically significant difference between the 3D and 4D image acquisition in group-1. There were no FLT-PET-related toxicities. FLT-PET is feasible in SBRT patients pre- and post-treatment, and may assist in distinguishing fibrosis from recurrent tumor. Further validation studies are needed.

Novel evaluation and treatment techniques for white spot lesions. An in vitro study.

White spot lesions (WSLs) are commonly seen during and after orthodontic treatment. Therefore, the objective of this in vitro study was to assess the effect of 45S5-bioglass in remineralizing WSLs using cross-polarization optical coherence tomography (CP-OCT) and confirm the findings by micro-hardness test. Ceramic orthodontic brackets were bonded to the buccal surface of 45 human premolars with Transbond XT primer followed by Transbond PLUS according to the manufacturer's instructions. Then, all specimens were varnished excluding the area of interest (AOI) around the bonded brackets, immersed in demineralizing solution and divided into three groups: BG, REM and CONT. In BG group, 15 specimens were treated with bioglass paste for 24hours. REM group had 15 specimens stored in remineralization solution for 24hours. CONT group had the remaining 15 specimens with no treatment. All specimens were examined under CP-OCT and tested using cross-sectional micro-hardness techniques. CP-OCT analysis showed that the maximum pixel value after bioglass application was significantly increased at AOI when compared to CONT and REM groups (P>.05), which was confirmed by the cross-sectional micro-hardness results (P>.05). Early enamel demineralization and remineralization can be easily and non-invasively monitored with CP-OCT. Bioglass is a potent remineralizing agent.

Generating HDR radiance maps from single LDR image

We present a method of generating high dynamic range (HDR) radiance maps from a single low dynamic range (LDR) image and its camera response function (CRF). The method first models and estimates the inverse CRF and then multiplies the inverse CRF by a weighting function to make it smooth near the maximum and minimum pixel values, and finally conducts the smooth inverse CRF on the input LDR image to generate HDR image. In the method, the inverse CRF is estimated using one single LDR image and an empirical model of CRF, based on measured RGB distributions at color edges. Unlike most existing methods, the proposed method expands image from both high and low luminance regions. Thus, the algorithm can avoid the artifacts and detail loss in dark area which results from extending image only from bright region. Extensive experimental results show that the approach induces less contrast distortion and produces high visual quality HDR image.

Difference in the craniocaudal gradient of the maximum pixel value change rate between chronic obstructive pulmonary disease patients and normal subjects using sub-mGy dynamic chest radiography with a flat panel detector system

ObjectivesTo compare the craniocaudal gradients of the maximum pixel value change rate (MPCR) during tidal breathing between chronic obstructive pulmonary disease (COPD) patients and normal subjects using dynamic chest radiography. Materials and methodsThis prospective study was approved by the institutional review board and all participants provided written informed consent. Forty-three COPD patients (mean age, 71.6±8.7 years) and 47 normal subjects (non-smoker healthy volunteers) (mean age, 54.8±9.8 years) underwent sequential chest radiographs during tidal breathing in a standing position using dynamic chest radiography with a flat panel detector system. We evaluated the craniocaudal gradient of MPCR. The results were analyzed using an unpaired t-test and the Tukey–Kramer method. ResultsThe craniocaudal gradients of MPCR in COPD patients were significantly lower than those in normal subjects (right inspiratory phase, 75.5±48.1 vs. 108.9±42.0s−1cm−1, P<0.001; right expiratory phase, 66.4±40.6 vs. 89.8±31.6s−1cm−1, P=0.003; left inspiratory phase, 75.5±48.2 vs. 108.2±47.2s−1cm−1, P=0.002; left expiratory phase, 60.9±38.2 vs. 84.3±29.5s−1cm−1, P=0.002). No significant differences in height, weight, or BMI were observed between COPD and normal groups. In the sub-analysis, the gradients in severe COPD patients (global initiative for chronic obstructive lung disease [GOLD] 3 or 4, n=26) were significantly lower than those in mild COPD patients (GOLD 1 or 2, n=17) for both right and left inspiratory/expiratory phases (all P≤0.005). ConclusionsA decrease of the craniocaudal gradient of MPCR was observed in COPD patients. The craniocaudal gradient was lower in severe COPD patients than in mild COPD patients.

Evaluation of the brightness of lightning channels and branches using the magnitude system: Application of astronomical photometry

In this paper, we have evaluated the brightness of lightning leaders shown in a digital still image by applying the astronomical magnitude system. In order to analyze the only lightning leaders, these were extracted from the digital still image. For photometry of the lightning leaders, there is no a standard reference source such as Vega in astronomical photometry. Therefore, assuming the maximum pixel value 255 (in 256 levels) as the brightness of a standard reference source, the magnitude of the lightning leaders was obtained. The result showed that the magnitude of the lightning leaders vary spatially (i.e. 2D spatial variability). Furthermore, the result suggested that a low current channel is high magnitude and a high current channel is low magnitude.

Removal of salt-and-pepper noise in corrupted image using three-values-weighted approach with variable-size window

The quality of a digital image deteriorates by the corruption of impulse noise in the record or transmission. The process of efficiently removing this impulse noise from a corrupted image is an important research task. This investigation presents a novel three-values-weighted method for the removal of salt-and-pepper noise. Initially, a variable-size local window is employed to analyze each extreme pixel (0 or 255 for an 8-bit gray-level image). Each non-extreme pixel is classified and placed into the maximum, middle, or minimum groups in the local window. The numbers of non-extreme pixels belonging to the maximum or the minimum group determines the centroid of the middle group. The distribution ratios of these three groups are employed to weight the non-extreme pixels with the maximum, middle, and minimum pixel values. The center pixel with an extreme value is replaced by the weighted value, thus enabling the noisy pixels to be restored. Experimental results show that the proposed method can efficiently remove salt-and-pepper noise (only for known extreme values of 0 and 255) from a corrupted image for different noise corruption densities (from 10% to 90%); meanwhile, the denoised image is freed from the blurred effect.

Lung Cancer Detection Using Fuzzy Auto-Seed Cluster Means Morphological Segmentation and SVM Classifier.

An effective fuzzy auto-seed cluster means morphological algorithm developed in this work to segment the lung nodules from the consecutive slices of Computer Tomography (CT) images to detect the lung cancer. The initial cluster values were chosen automatically by averaging the minimum and maximum pixel values in each row of an image. The area and eccentricity features were used to eliminate the line like structure and very tiny clusters less than 3mm in size. The change in centroid analysis was carried out to eliminate the blood vessels. The tissue clusters whose centroid varies much in consecutive slices must be blood vessels. After eliminating the blood vessels, the co-occurrence matrix based texture features contrast, homogeneity and auto correlation were computed on the remaining nodules from the consecutive CT slices to discriminate the calcifications. The extracted centroid shift and texture features were used as the inputs to the Support Vector Machine (SVM) kernel classifier in order to classify the real malignant nodules. This work was carried out on 56 malignant (cancerous) cases and 50 normal cases (with lung infections), which had a total of 56 malignant nodules and 745 benign nodules. Out of these, 60% of subjects (34 cancerous & 30 non-cancerous) were used for training. The remaining 40% subjects (22 cancerous & 20 non-cancerous) were used for testing. This work produced a good sensitivity, specificity and accuracy of 100%, 93% and 94%, respectively. The False Positive (FP) per patient was calculated as 0.38.

SU‐F‐J‐222: Using PET Imaging to Evaluate Proliferation and Blood Flow in Irradiated and Non‐Irradiated Bone Marrow 1 Year After Chemoradiation Therapy

Purpose:To compare proliferation and blood flow in pelvic and thoracic bone marrow 1 year after pelvic chemoradiation.Methods:Sixteen pelvic cancer patients were enrolled in an IRB‐approved protocol to acquire FLT PET images during radiation therapy simulation (baseline) and 1 year after chemoradiation therapy. Three subjects also had optional O‐15 water PET images acquired 1 year after chemoradiation therapy. Baseline FLT PET images were used to create IMRT plans to spare pelvic bone marrow identified as regions with FLT SUV ≥ 2 without compromising PTV coverage or OAR sparing. Marrow VOIs were defined using a 50% maximum pixel value threshold on baseline FLT PET images (VIEW, PMOD version 3.5) in the sacrum and thoracic spine representing irradiated and non‐irradiated regions, respectively. FLT PET and O‐15 water PET images acquired 1 year after therapy were co‐registered to baseline images (FUSION PMOD) and the same VOIs were used to measure proliferation (FLT SUV) and blood flow (O‐15 water uptake). Separate image‐based input functions were used for blood flow quantitation in each VOI.Results:Mean 1 year FLT SUV in sacral and thoracic VOIs for were 1.1 ± 0.4 and 6.5 ± 1.7, respectively for N = 16 subjects and were 1.2 ± 0.2 and 5.6 ± 1.6, respectively for N = 3 subjects who also underwent O‐15 water imaging. Blood flow measures in equivalent sacral and thoracic marrow regions (N = 3) were 21.3 ± 8.7 and 18.3 ± 4.9 mL/min/100mL respectively.Conclusion:Decreased bone marrow proliferation measured by FLT SUV does not appear to correspond to decreased blood flow as measured by O‐15 water PET imaging. Based on this small sample at a single time point, reduced blood supply does not explain reductions in bone marrow proliferative activity 1 year after chemoradiation therapy.

SU‐F‐T‐302: Implementation of the RadCalc Image Analysis Tool for IMRT QA

Purpose:To assess RadCalc as a means for analyzing fluence maps of IMRT QA patient plans. Eclipse generated fluence maps were compared to RadCalc fluence maps generated from both Eclipse parameters and from dynalog trajectory files.Methods:Six IMRT plans consisting of fifty individual fields were compared both field‐by‐field and as composite plans. These plans were exported from Eclipse to RadCalc. Each plan was then delivered in QA mode on a Varian Clinac iX, while recording and saving the dynalog trajectory files. These files were then imported into RadCalc, providing three sources of generating fluence maps: Eclipse, RadCalc, and dynalog files. Using the image analysis tool in RadCalc, a gamma analysis was then performed as a point‐by‐point comparison for each IMRT field. The Eclipse fluence map was used as the baseline for each comparison.Results:Based on the manufacturer's recommendations, all fields were normalized to the maximum pixel value within each Eclipse field. All data was analyzed using a gamma index of 3mm/3% with passing criteria of 90%. For both dynalog analysis and RadCalc fluence analysis, 48/50 created fluence maps passed at greater than 90% when compared with the Eclipse baseline. In analyzing the composite of each of the six patients’ plans, all plans passed over 90%.Conclusion:Using the dynalog trajectory files in combination with RadCalc Version 6.3 image analysis is a promising metric for verifying IMRT QA passing rates. Notably, if a field failed, it did so for both dynalog and RadCalc compared to Eclipse. This suggests RadCalc can accurately simulate fluence maps, with similar results to dynalog comparisons. Limitations within the RadCalc software were discovered in the analytical process such as pixel resolution and the inability to set minimum threshold values. Comparisons could be extended to include dose map and distance to agreement analysis by expanding software capabilities.

PVO based Reversible Data Hiding with Improved Embedding Capacity and Security

Background/Objectives: Pixel Value Ordering (PVO) based embedding is a method for image based Reversible Data Hiding (RDH) to plant secret data in minimum and maximum pixel values of each block of the image. This paper serves as an extension of a recently proposed PVO scheme with higher security and embedding capacity. Methods/Statistical Analysis: In this proposed method the image is first divided into equal sized non-overlapping blocks. The pixels in the individual blocks are ordered according to their values and differences between the maximum and the second largest (or minimum and the second smallest) are computed. Then, histograms of these differences are modified to hide secret information. But original scheme rejects a lot of blocks belonging to textured regions of the image which can be used to embed even more data. Findings: The proposed scheme extends the original PVO method by using these rejected blocks to embed data thus increasing the Embedding Capacity. It is observed that although there is an increase in the overall embedding capacity, the degradation in the visual quality is negligible. It is also found that this increase in the capacity affects the robustness. So a simple randomization technique for the block selection process is also proposed. Applications/Improvements: This method can be applied for all the secret communication applications especially Defence, Telemedicine, etc. This proposed method developed further in terms of robust against various steganalysis tools.

Lesion Area Detection (LAD) using Superpixel Segmentation

Nowadays, in biomedical field, imaging techniques are used to discover the abnormalities in the particular region. Lesion is an area in an organ or tissue, which has suffered from damage through injury or disease, such as a wound, ulcer, abscess, or tumor. Lesion area of the tissue is detected using source images. Wireless capsule endoscopy image of the gastrointestinal tract is used to find the lesion. Preprocessing of image is done using denoising by multidimensional filter. Denoised image is edge detected during which the edge points in an image differentiation is highlighted by Sobel edge detection. The value of each pixel in the edge detected image is evaluated based on the comparison of corresponding pixel in the input image with its neighboring pixels by the morphological operation. Erosion and dilation operation erodes and adds pixels respectively to the edge detected image, so that the value of the output pixel has the maximum pixel value. During segmentation, the pixels are grouped using superpixel algorithm to reduce the complexity while maintaining high diagnostic accuracy. As a final point, the Correlation coefficient test finds the spoiled area between healthy tissue and abnormal tissue by color encoding. This intends to identify the suspected abnormal areas (lesion) from the source images.

Optimum Global Thresholding Based Variable Block Size DCT Coding For Efficient Image Compression

Image compression is dissimilar than compressing other unprocessed binary data. Obviously, general purpose compression techniques deliberated for raw binary data can be used to compress images, but the result is not the finest one, because of the variations in statistical property of image. Statistical properties of image must be completely exploit by encoders to obtained efficient image compression. The most popular transform coder was developed by the Joint Photographic Experts Group (JPEG), which utilizes fixed block size discrete cosine transform (DCT) to obtain image data decorrelation. With fixed block size DCT, JPEG has no independent control over quality and bit rate simultaneously. Human visual system is less sensitive to quantization noise in high-activity areas of an image than in low-activity areas. That means the threshold of visibility of quantization noise is higher in areas with details than in flat areas. this is the key, why not exploit human visual system’s weakness to achieve much higher compression with good visual quality by hiding as much quantization noise in busy areas as possible. It is indeed possible by using DCT with varying block sizes and quantizing busy areas heavily and flat areas lightly. To apply variable block size DCT transform on an image, quad tree decomposition technique is commonly used. In quad tree decomposition technique a square block is divides in smaller blocks, if the difference between maximum and minimum pixel values exceeds a threshold. This threshold selection plays a very crucial role, because the independent selection of threshold value without considering the statistical properties of the input image, may lead to even worst compression characteristics. To address this difficulty, this paper proposes a novel optimum global thresholding based variable block size DCT coding for efficient image compression. The proposed method calculates the required threshold value for blocks decomposition using optimum global thresholding technique, which exploits the edge characteristics of the image. Comparison has been made with baseline fixed block size DCT coder by using mean square error (MSE), peak signal to noise ratio (PSNR) and compression ratio (CR) as criterions. It is shown that the variable block size DCT transform coding system using proposed optimum global thresholding technique has better MSE and highly improved PSNR and CR performance for all test images.

Grey scale texture analysis of endobronchial ultrasound mini probe images for prediction of benign or malignant aetiology

Expert analysis of endobronchial ultrasound mini probe (EBUS-MP) images has established subjective criteria for discriminating benign and malignant disease. Minimal data are available for objective analysis of these images. The aim of this study was to determine if greyscale texture analysis could differentiate between benign and malignant lung lesions. Digital EBUS-MP images with a gain setting of 10/19 and contrast setting of 4/8 from 2007 until 2012 inclusive were included. These images had an expert-defined region of interest (ROI) mapped. ROI were analysed for the following greyscale texture features: mean pixel value, difference between maximum and minimum pixel value, standard deviation of the mean pixel value, entropy, correlation, energy and homogeneity. Significant greyscale texture features differentiating benign from malignant disease were used by two physicians to assess a validation set. A total of 167 images were available. The first 85 lesions were used in the prediction set. Benign lesions had larger differences between maximum and minimum pixel values, larger standard deviations of the mean pixel values and higher entropy than malignant lesions (P < 0.0001 for all values). A total of 82 peripheral lesions were in the validation set. Physician 1 correctly classified 63/82 (76.8%) with a negative predictive value (NPV) for malignancy of 82% and positive predictive value (PPV) of 75%. Physician 2 correctly classified 62/82 (75.6%) with a NPV of 100% and PPV of 71.0%. Greyscale texture analysis of EBUS-MP images can help establish aetiology with a high NPV for malignancy.

논 잡초 방제용 자율주행 로봇을 위한 벼의 형태학적 특징 기반의 주행기준선 추출

In this paper, we proposed a new algorithm of the guidance line extraction for autonomous weeding robot based on infrared vision sensor in wet paddy. It is the critical process for guidance line extraction which finds the central point or area of rice row. In order to improve accuracy of the guidance line, we are trying to use the morphological characteristics of rice that the direction of rice leaves have convergence to central area of rice row. Using Hough transform, we were represented the curved leaves as a combination of segmented straight lines on binary image that has been skeletonized and segmented object. A slope of the guidance line was gotten as calculate the average slope of all segmented lines. An initial point of the guidance line was determined that is the maximum pixel value of the accumulated white columns of a binary image which is rotated the slope of guidance line in the opposite direction. We also have verified an accuracy of the proposed algorithm by experiments in the real wet paddy.

SU‐E‐I‐12: Characterization of Edge Effects in a Commercial Low‐Dose Image Processing System

Purpose:Minimizing radiation dose while preserving image quality is critical in fluoroscopic imaging. One recent development is a noise reduction system (Allura Clarity) offered by Philips. Others have reported approximately 50% reduction in air kerma when using Clarity. These studies, however, provide only a cursory look at how the Clarity system affects image quality. The purpose of this work was to evaluate the effect of Clarity on the appearance of high‐frequency image information.Methods:A lead attenuator with a smooth edge was imaged on two Philips Allura FD20 detectors: one with Clarity and one without. The edge was positioned in the center of the field of view and images were obtained under the following conditions: 40cm and 11cm fields of view, single shot and continuous fluoroscopy modes, and using abdomen and cardiac protocols, for a total of sixteen imaging conditions. Profiles were drawn perpendicular to the edge across 80% of its length, averaged to reduce noise, normalized to the maximum pixel value, and plotted as a function of distance.Results:For all single‐shot acquisitions and most fluoroscopic images, overshoot of the edge was observed. This effect was more substantial for single‐shot acquisitions (∼20%) than for fluoroscopic images (∼50%). For fluoroscopic acquisition, the overshoot decayed more quickly with the Clarity system. However, the system with Clarity introduced a ringing effect for both single‐shot and fluoroscopic images that is not present on the non‐Clarity system.Conclusion:Previous reports have demonstrated a substantial dose reduction when using Clarity but the impact this has on image appearance has not been characterized. One demonstrated difference is the change in appearance of high‐frequency image information. It remains to be determined whether this effect may impact clinical images adversely.

Human Machine Interface for controlling a robot using image processing

This paper introduces a head movement based human machine interface (HMI) that uses the right and left movements of head to control a robot motion. An approach for making an effective technique for real-time face orientation information system, to control a robot which can be efficiently used for electrical powered wheelchair (EPW). The project aims at application related to HMI, the system (machine) identifies the orientation of the face movement with respect to the pixel values of image in a certain areas. The whole image is divided into three parts on the basis of x value of image (x, y). On the basis of orientation of face, maximum pixel value of approximate same range lie in one of divided parts. This information will be transferred to the microcontroller through serial communication port and control the motion of robot in real time by using head movements.

The Effect of Light Conditions on Photoplethysmographic Image Acquisition Using a Commercial Camera.

Cameras embedded in consumer devices have previously been used as physiological information sensors. The waveform of the photoplethysmographic image (PPGi) signals may be significantly affected by the light spectra and intensity. The purpose of this paper is to evaluate the performance of PPGi waveform acquisition in the red, green, and blue channels using a commercial camera in different light conditions. The system, developed for this paper, comprises of a commercial camera and light sources with varied spectra and intensities. Signals were acquired from the fingertips of 12 healthy subjects. Extensive experiments, using different wavelength lights and white light with variation light intensities, respectively, reported in this paper, showed that almost all light spectra can acquire acceptable pulse rates, but only 470-, 490-, 505-, 590-, 600-, 610-, 625-, and 660-nm wavelength lights showed better performance in PPGi waveform compared with gold standard. With lower light intensity, the light spectra >600 nm still showed better performance. The change in pulse amplitude (ac) and dc amplitude was also investigated with the different light intensity and light spectra. With increasing light intensity, the dc amplitude increased, whereas ac component showed an initial increase followed by a decrease. Most of the subjects achieved their maximum averaging ac output when averaging dc output was in the range from 180 to 220 pixel values (8 b, 255 maximum pixel value). The results suggested that an adaptive solution could be developed to optimize the design of PPGi-based physiological signal acquisition devices in different light conditions.