Color Imaging Technology Research Articles

Application of Image Color Gamut Boundary Judgment Algorithm in Digital Media

Image chromatic aberration evaluation is one of the research hotspots and academic difficulties in the field of color science and imaging technology. Based on the algorithm theory of image color gamut boundary judgment, this paper constructs its application model in digital media. The model uses the threshold color difference image as a reference and applies it to the evaluation experiment of color difference above the threshold based on the quantitative estimation method. During the simulation process, the improved HAD dual-color image digital boundary judgment algorithm is programmed. For small color difference data at the threshold level, the calculated color difference of the boundary judgment algorithm framework is smaller than the visual perception color difference; for the large color difference data above the threshold, the boundary judgment algorithm framework is given. The research results of the threshold color difference experiment show that the perceptible color difference threshold and acceptable color difference threshold of image color gamut observers for image color difference are 1.85 AE and 3.63 AE, respectively, which are basically twice the relationship. The visually perceptible chromatic aberration threshold and acceptable chromatic aberration threshold for lightness parameters are higher than those of chroma and hue, which shows that the boundary judgment algorithm framework has certain advantages for the evaluation performance of color digital image threshold chromatic aberration and effectively improves the algorithm robustness.

Research on 3D MFL testing of wire rope based on empirical wavelet transform and SRCNN

Magnetic flux leakage (MFL) testing is one of the most effective methods in nondestructive testing of wire rope. However, traditional MFL testing devices have problems such as low recognition rate, single detection dimension and fuzzy magnetic leakage image. Based on the non-saturated magnetic excitation 3D MFL testing device, this paper proposes a wavelet denoising method based on empirical wavelet transform (EWT) to denoise the collected 3D MFL signal. After noise reduction, the Signal-to-Noise Ratio (SNR) and Root Mean Squared Error (RMSE) of the three dimensions have improved. Color imaging technology is used to fuse defect grayscale images into color images, and Super-Resolution Convolutional Neural Network (SRCNN) is applied to MFL images of broken wires. After SRCNN reconstruction, the resolution of defect color images is improved. The color moment feature of the defect color image is extracted as the input of the Elman neural network to quantitatively identify broken wires. Experimental results show that the noise reduction algorithm can effectively suppress the noise in three dimensions, and the broken wires recognition rate after reconstruction has been significantly improved, which verifies the effectiveness of SRCNN in wire rope MFL images.

Improved adenoma detection with linked color imaging technology compared to white-light colonoscopy

ObjectivesLinked color imaging (LCI) is a new endoscopic technology that may increase colorectal adenoma detection rate (ADR) and polyp detection rate (PDR) by virtual chromoendoscopy. Aim of the present study was to evaluate the effectiveness of LCI in ADR and PDR compared to the HD white-light colonoscopy (WLC) technique.Materials and methodsBetween October 2016 and June 2018, we enrolled consecutive outpatients prospectively. Eligible patients allocated randomly to undergo HD WLC or LCI colonoscopy technique during instrument withdrawal. Each colonoscopy was performed in a single center by the same three expert endoscopists (with expertise more than 5000 colonoscopies).ResultsA total of 1278 patients underwent colonoscopy in the study period. ADR and PDR were significantly higher in the LCI group compared to the WLC group (34.4% vs. 26.8%; p = .007; and 53.3% vs 46.4%; p = .023, respectively). Similarly, the mean number of adenomas per patient (MAP) was significantly higher with the LCI than WLC (0.64 vs 0.44, respectively; p = .002). The mean age of patients at the time of colonoscopy was 51.95 years (SD = 13.861) in the LCI group and 51.96 years (SD = 14.028) in the WLC group. No significant differences observed in patient demographic characteristics (there was no difference in gender and age distribution, p = .986), quality of colonoscopy preparation and withdrawal times (WT) between the two groups (WLC and the LCI groups, 493.9 (SD: 143.5) and 514.0 (SD: 139.5) sec, respectively).ConclusionsAccording to our results, LCI virtual chromoendoscopic technology was superior compared to conventional HD WLC in detecting colorectal polyps and adenomas.

Quantitative Detection of Wire Rope Based on Three-Dimensional Magnetic Flux Leakage Color Imaging Technology

In the field of nondestructive testing (NDT) of wire rope, magnetic flux leakage (MFL) detection is the most widely used method. The traditional single-dimensional MFL detection system has the disadvantages of large volume, heavy weight, low sensitivity and low recognition rate. In order to overcome these problems, this paper designed the three-dimensional MFL acquisition system based on unsaturated magnetic excitation using the tunnel magnetoresistive (TMR) elements and proposed the three-dimensional MFL detection method. We mapped the three-dimensional MFL signals after noise reduction to Red-Green-Blue (RGB) space for color imaging. Then, the localization and segmentation algorithms were used to crop color images of broken wire defects. Finally, the color moment eigenvalues of color images of six types broken wire defects were extracted as the input of the back propagation (BP) neural network to quantitatively identify the broken wires. From the experimental results of the quantitative identification of broken wire defects, it can be seen that it is feasible to use the color images of the three-dimensional MFL signals to quantitatively identify the broken wire defects. Moreover, the three-dimensional MFL color imaging can effectively improve the recognition rate of broken wires.

Automated phenotyping for early vigour of field pea seedlings in controlled environment by colour imaging technology.

Early vigour of seedlings is a beneficial trait of field pea (Pisum sativum L.) that contributes to weed control, water use efficiency and is likely to contribute to yield under certain environments. Although breeding is considered the most effective approach to improve early vigour of field pea, the absence of a robust and high-throughput phenotyping tool to dissect this complex trait is currently a major obstacle of genetic improvement programs to address this issue. To develop this tool, separate trials on 44 genetically diverse field pea genotypes were conducted in the automated plant phenotyping platform of Plant Phenomics Victoria, Horsham and in the field, respectively. High correlation between estimated plant parameters derived from the automated phenotyping platform and important early vigour traits such as shoot biomass, leaf area and plant height indicated that the derived plant parameters can be used to predict vigour traits in field pea seedlings. Plant growth analysis demonstrated that the “broken-stick” model fitted well with the growth pattern of all field pea genotypes and can be used to determine the linear growth phase. Further analysis suggested that the estimated plant parameters collected at the linear growth phase can effectively differentiate early vigour across field pea genotypes. High correlation between normalised difference vegetation indices captured from the field trial and estimated shoot biomass and top-view area confirmed the consistent performance of early vigour field pea genotypes under controlled and field environments. Overall, our results demonstrated that this robust screening tool is highly applicable and will enable breeding programs to rapidly identify early vigour traits and utilise germplasm to contribute to the genetic improvement of field peas.

Linked color imaging improves detection of minimal change esophagitis in non-erosive reflux esophagitis patients.

Background and study aims Non-erosive reflux disease (NERD) includes minimal change esophagitis (MCE) and no endoscopic abnormalities. However, for most endoscopists, it is difficult to detect MCE with conventional white-light endoscopy (WLE). Linked color imaging (LCI) technology is the most recently developed image-enhancing technology and improves detection and differentiation of subtle mucosal changes using a color contrast method. This study assessed the efficacy of WLE combined with LCI for diagnosing MCE compared with WLE. Patients and methods Between February and May 2017, 44 NERD patients and 40 healthy subjects were enrolled in our study. First, the distal esophagus was examined using WLE followed by LCI. Second, three experienced endoscopists observed all the patients’ white-light (WL) images and corresponding images of WL and LCI and then recorded presence or absence of minimal change esophagitis (MCE +/–). The proportion of minimal change between the two groups was then compared. Third, five blinded endoscopists with different levels of endoscopic experience assessed whether MCE was present. Intraobserver reproducibility and interobserver agreement were described using the kappa value. Results The proportion of MCE in the NERD group (70.8 %, 35/48) was higher than that in the control group (22.5 %, 9/40, P < 0.001) when diagnosed by the three experienced endoscopists. Detection rates for MCE using WLE combined with LCI were higher than those using WLE (43/88, 48.9 % vs. 29/88, 33.0 %, P < 0.001). With WLE combined with LCI, intraobserver reproducibility significantly improved, indicating that the combined approach can improve interobserver agreement compared with using WLE alone. Conclusions Endoscopic diagnosis of MCE using WLE combined with LCI images is effective. Intraobserver reproducibility and interobserver agreement in MCE can be improved when LCI is applied with conventional imaging (Clinical trial registration number: NCT03068572).

Telangiectasia Detection in Wireless Capsule Endoscopy Using the Color Slicing Technique.

Wireless capsule endoscopy represents a color imaging technology in the field of medical endoscopy that is extensively used to detect lesions of the human digestive tract. It is the golden standard in evaluating small bowel lesions, offering a set of digital snapshots difficult to get using other investigation methods. Its major drawbacks are the time consumed for image analysis and the burden for the physicians that must spot and classify lesions within more than 55000 images. This paper carries out a study on the detection of telangiectasia in the small bowel, based on an adapted color slicing technique applied not only on unique frames, but on series of successive frames, performing a global analysis suitable on partial sequences or entire wireless capsule endoscopy movies. We have quantified the extracted features and determined a weighting algorithm to find telangiectasia lesions. For frames containing potential lesions, we have determined features not only for the global image, but also for the normal mucosa surrounding the lesion extracted from the image. This approach allows the physician to see variations of parameters within a frame or a sequence that contains lesions. Experimental results prove that the algorithm is effective in detecting telangiectasia patterns of different images, with an accuracy of 93.88%, reducing thus the time spent for the analysis of the images acquired by wireless capsule endoscopy.

Strengths and limitations of a uniform 3D-LUT approach for digital camera characterization

Digital color imaging technology has become omnipresent in today’s modern life. Digital image capturing and reproduction devices such as smartphones, digital still and video cameras, displays, printers, and color scanners can be found in every home, offering extremely high functionality and flexibility. In order to guarantee qualitatively good results regarding the whole image processing pipeline and to achieve high user acceptance, optimized color conversion and correction algorithms play a crucial role. In this context, a new implementation method of uniform three-dimensional lookup tables (3D-LUTs) based on a standardized pre-measured spectral reflectance database will be presented and applied for the color correction of digital camera systems. The strengths and limitations of such an implementation will be discussed and a performance comparison with the standard 3×3 matrix color correction will be conducted. It can be found that the proposed 3D-LUT approach outperforms the matrix method in terms ofCIEDE2000 color differences and color reproduction properties, but still has its limitations when it comes to achromatic colors and the representation ofcolor gradients.

Laterally Spreading Tumor of the Rectum Delineated with Linked Color Imaging Technology.

Colonoscopy has been shown to decrease the incidence of colorectal cancer and cancer death through the removal of adenomatous polyps. To make an accurate diagnosis of colorectal neoplasms, several image-enhanced endoscopic systems, such as narrow band imaging (NBI), flexible spectral imaging color enhancement, and blue laser imaging (BLI), have been developed. However, no significant differences have been reported in the adenoma detection rate between image-enhanced endoscopy and conventional white light endoscopy [1]. NBI and BLI are often criticized for darkening the endoscopy image and, in turn, hampering a wider view of the colon [2]. Moreover, the miss rate for flat lesions was significantly higher than that for pedunculated lesions [3]. We present a case that suggests a possible improvement in adenoma detection rates, especially for flat adenomas.

Special issue on real-time color image processing

Color perception plays an important role in object recognition and scene understanding both for humans and intelligent vision systems. Recent advances in digital color imaging and computer hardware technology have led to an explosion in the use of color images in a variety of applications including medical imaging, content-based image retrieval, biometrics, watermarking, digital inpainting, remote sensing, visual quality inspection, among many others. As a result, automated processing and analysis of color images has become an active area of research, which is witnessed by the large number of publications during the past two decades. The multivariate nature of color image data presents new challenges for researchers and practitioners as the numerous methods developed for singlechannel images are often not directly applicable to multichannel images. In addition, common scalar image processing operations often become computationally intractable when performed in high-dimensional spaces. As a result, the development of computationally practical methods for color image processing has become an important research area. The goals of this special issue are to summarize the state-of-the-art in real-time color image processing and to provide future directions for this exciting subfield of image processing. The intended audience includes researchers and professionals, who are increasingly dealing with the processing and analysis of color images and video. The special issue opens with ‘‘Design of a Shift-andAdd Based Hardware Accelerator for Color Space Conversion’’ by Li et al. The authors propose a hardware/software co-design architecture for Nios II, a 32-bit embedded processor. The architecture integrates a pipelined color space converter hardware accelerator based on a genetic algorithm and an LCD touch module. When implemented on a system-on-a-programmable-chip, the proposed architecture is capable of converting a 512 512 RGB image to YCbCr in 0:11 s. The special issue continues with seven articles on color image enhancement. In ‘‘A Simple Gray-Edge Automatic White Balance Method with FPGA Implementation,’’ Tan et al. propose a real-time automatic white balance method based on the gray-edge hypothesis. To reduce computational time, the method employs horizontal downsampling using the mean filter and gradient computation using horizontal first-order difference operator. The authors demonstrate the practicality of their approach using an FPGA implementation. In ‘‘A Full Linear 3 3 Color Correction between Images,’’ Lecca describes a fast color correction algorithm that is capable of equalizing the colors of two images of the same scene that are acquired under different illuminants and/or by different devices. The author demonstrates the performance of her approach against two state-of-the-art approaches on a variety of synthetic and real-world image databases. The method has linear time complexity in the M. E. Celebi (&) Department of Computer Science, Louisiana State University, Shreveport, LA, USA e-mail: ecelebi@lsus.edu

Spatial gamut mapping algorithms for cross‐display color reproduction

Abstract— Owing to the fast developments of computer networks and color imaging technologies, there is a tendency towards remote proofing in the printing or textile industries. More cases such as cross‐display color matching will occur in the future information society. The problems of color mismatching we usually find in cross‐display devices have been widely discussed today. In this paper, to achieve equivalent color matching between a sRGB monitor and an Adobe RGB monitor, the spatial gamut mapping algorithm (SGMA), which introduces sigmoidal tone mapping, multi‐mapping paths, and unsharp mask (USM) operation into a sRGB color‐management system, is proposed. According to the designs of USM locations, this proposed SGMA can be further developed into pre‐USM, post‐USM, and double‐USM types. Besides, two critical image characteristics, edge map and color histogram, are investigated to establish the relationship between image content and SGMA. The psychophysical experimental results show that double‐USM SGMA obtains better color matching than the other spatial types.

Beyond Red&amp;#x2013;Green&amp;#x2013;Blue (RGB): Spectrum-Based Color Imaging Technology

This article presents a comprehensive study on the spectrum-based color reproduction system, called Natural Vision (NV), which aims to break through the limitation of red&#x2013;green&#x2013;blue (RGB) three-primary schemes. After a basic discussion on the motivation for color imaging technology beyond RGB, the method for systematizing the multispectral and multiprimary color imaging technologies, including image capture, processing, storage, printing, and display, is presented. Then experimental multispectral systems for both still image and video are introduced, and the following features of spectrum-based scheme are revealed: a) highly accurate color reproduction is possible even under different illumination environment, b) an expanded color gamut can be reproduced by multiprimary color displays, c) the influence of observer metamerism can be reduced by the spectral color reproduction, and d) the quantitative spectral attributes of an object, useful for its analysis or recognition, can be captured and preserved. Finally, the effectiveness of the system is also demonstrated through experiments in fields of application, such as medicine, digital archives, color printing, electronic commerce, and computer graphics.

Modeling the effects of gamma on the colors displayed on cathode ray tube monitors

This work has been motivated by the rapid growth in the use of digital color imaging technology, together with the ever-increasing interchange of images over the internet. Users of these systems frequently have to make assumptions about the viewing conditions under which such images will be used, as well as the properties of the devices on which the images will be displayed. In this work, we focus on the way in which the displayed colors on a cathode ray tube (CRT) monitor are influenced by the gamma of the display. We have used a simple gain-offset-gain-type model of the performance of the CRT, with gain and offset values K1 = 1.15, K2 = –0.15, together with a set of standard assumptions regarding the display primaries and the white point setting, to enable us to simulate the influence of monitor gamma on the colors displayed. Color differences have been computed in the CIELAB color space. A total of 76 numerically defined color samples were used, of which 66 were chromatic samples and ten achromatic. They were subjected to the influence of eight different gamma values. A reference gamma of 2.2 was assumed in making colorimetric comparisons of the displayed colors for the different "test" gammas against the colors displayed under the reference gamma. The comparisons have been expressed as CIELAB color differences, and they show that the color shifts can be significant (up to 3.58 CIELAB units for a single simulated color sample with a gamma "discrepancy" of 0.1, and up to 9.90 CIELAB units when the gamma discrepancy is 0.3). These results are of concern in the context of the "correct" display of color reproductions—for example, in applications where an accurate impression or understanding of the displayed color is important.

Generation of an ICC Profile from a Proprietary Style File

In color imaging technologies one of the major parts of the scanning procedure is processing the raw RGB scanner data to make it suitable for printing on a given CMYK output device. The processing typically involves applying a number of technical and aesthetic, iteratively developed edits. These edits are stored in a proprietary file format, i.e. a type of vendor-specific macro file. There has been a recent shift from this closed loop type of color control to the open system of color management such as that specified by the International Color Consortium (ICC). ICC color managed workflows can only use a universally agreed file called a profile, and not proprietary user edit files. It may have taken a long time to perfect the proprietary edits and users will not want to lose them when they migrate to the new ICC workflows. This article describes a process that allows users to convert color edit information from a vendor-specific proprietary edit file into an ICC profile. The proposed system works by analyzing the proprietary edit information and then incorporating this information into an input profile. The application of the input profile and an output profile then produces a set of processed CMYK values that, when printed on the target printer produce essentially the same result as that achieved through the proprietary route. As a major part of the process relies on the generation of an accurate input profile, a polynomial fitting process and an empirical process are investigated for use in generating the transform relationship. This research also considers the reversibility of the output profile and a process to ensure accurate reversibility of the output profile is presented. A discussion is presented on the choice of rendering intents available and the different situations where each would be appropriate to use. Experimental results are presented for the whole process based on a test transparency that contains an image of a Macbeth ColorChecker chart. Quantitative results are presented to show how an ICC profiled system can be created that mimics a given proprietary reproduction style to within 2&#x394;E. This research demonstrates how novel image engineering applications can be constructed from within the ICC framework.

S3-2 自然な色再現を実現する映像技術 : ナチュラルビジョン

S3-2 自然な色再現を実現する映像技術 : ナチュラルビジョン

Full-field automatic evaluation of an isoclinic parameter in white light

In this paper, a technique for full-field evaluation of the isoclinic parameter is presented. It combines the phase-shifting method with true color imaging technology to minimize the interaction between isoclinic and isochromatic fringes. The paper also shows how the proposed technique can be suitably integrated with known methods for evaluating the retardations. Furthermore, a digital algorithm for filtering wrapped phase data obtained by general phase-shifting techniques is presented.

Color Imaging in Telemedicine: Current Trends &amp;amp; Future Needs

This paper will examine the many complex issues surrounding the effective use of color imaging as an integral part of telemedicine systems. This includes an overview of common color medical imaging techniques and the color needs of each as well as a discussion of global issues that contribute to the viability of this technology; thereby highlighting roles that imaging professionals can play to increase the value of color imaging technology in healthcare by ensuring that color applications in telemedicine benefit from optimal technical solutions.

New color technology uses microcapsules

Mead Imaging has high hopes for a new reproduction technology it has developed and calls Cycolor. Mead Imaging president Charles W. Joiner Jr. says that the technology is simple and cost-effective enough that reproduction need no longer be an expensive luxury. Instead, he says, color can become the standard for all business Cycolor is a color, photographic-like, film technology. No silver halide is used, and the film is sensitive to visible light. Calling Cycolor a major break-through in color-imaging technology, Joiner says that it will make possible the development of office equipment that would bring the graphic impact of to everyday business communications. Using the new process, he explains, companies would be able to make the use of hard copy and overhead transparencies standard business practice. That, at least, is Mead Imaging's hope. The company was formed in 1984 as a division of Mead Corp., a forest products and electronic ...

A Fundamentally New Colour Imaging Technology for Instant Photography

AbstractThe Kodak instant print film is based on a fundamentally new colour-imaging technology. The imaging chemistry involves new types of compounds that release dyes for diffusion to a viewing region of the picture unit as a conse-quence of development of a new type of relatively high speed direct reversal emulsion. The chemical structures of the dyes were selected as a result of theoretical studies. The colour pictures produced by them feature a high level of colour fidelity.