Robust Parameter Design of Derivative Optimization Methods for Image Acquisition Using a Color Mixer

Kim, Hyung-Tae; Cho, KyeongYong; Kim, Jong-Seok; Jin, Kyung-Chan; Kim, SeungTaek

doi:10.3390/jimaging3030031

Cited by 5 publications

(4 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the AF should be joined with the ODS, i.e., the AF should be performed based on the ODS results. The AF determines a focal position at the optimum of contrast, σ, according to movement along the optical axis near z d [29]. The range of the movement near z d , δ, is a small value.…”

Section: Surface Flatness Of Conductive Vacuum Chuckmentioning

confidence: 99%

On-Machine Measurement for Surface Flatness of Transparent and Thin Film in Laser Ablation Process

et al. 2020

Self Cite

View full text Add to dashboard Cite

In printed electronics, laser ablation is used to repair defective patterns on transparent, flexible, and thin films, using high-power lasers. The distance between the film surface and laser focus is sensitive to changes as the narrow focus depth of the lens is the range of tens of microns. However, a film fixed on a conductive vacuum chuck (CVC) is always curved, owing to chucking bending; thus, laser focusing must be locally performed before ablation. Therefore, this study proposes a non-contact measurement method for the surface flatness of a transparent and thin film, to compensate for laser defocusing in a large area. The surface flatness was obtained using camera-focus points on the porous surface of the CVC. The focus points were interpolated to achieve a smooth and continuous surface flatness for chucking bending. A laser distance sensor was used to verify the surface flatness from the proposed method. The surface flatness was used to inspect the printed patterns, and to perform laser ablation on the film. The proposed method is advantageous for large-area laser ablation and is expected to become indispensable for repairing machines in printed electronics.

show abstract

Section: Surface Flatness Of Conductive Vacuum Chuckmentioning

confidence: 99%

On-Machine Measurement for Surface Flatness of Transparent and Thin Film in Laser Ablation Process

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Contrast is the perceived visual differences between the different structures within the image [29]. Sharpness is the visibility of small structures as measured by the deviation and difference of grey levels in the image [30].…”

Section: Noise Sharpness and Contrast In Grayscale Imagesmentioning

confidence: 99%

Local Indicators of Spatial Autocorrelation (LISA): Application to Blind Noise-Based Perceptual Quality Metric Index for Magnetic Resonance Images

et al. 2019

View full text Add to dashboard Cite

Noise-based quality evaluation of MRI images is highly desired in noise-dominant environments. Current noise-based MRI quality evaluation methods have drawbacks which limit their effective performance. Traditional full-reference methods such as SNR and most of the model-based techniques cannot provide perceptual quality metrics required for accurate diagnosis, treatment and monitoring of diseases. Although techniques based on the Moran coefficients are perceptual quality metrics, they are full-reference methods and will be ineffective in applications where the reference image is not available. Furthermore, the predicted quality scores are difficult to interpret because their quality indices are not standardized. In this paper, we propose a new no-reference perceptual quality evaluation method for grayscale images such as MRI images. Our approach is formulated to mimic how humans perceive an image. It transforms noise level into a standardized perceptual quality score. Global Moran statistics is combined with local indicators of spatial autocorrelation in the form of local Moran statistics. Quality score is predicted from perceptually weighted combination of clustered and random pixels. Performance evaluation, comparative performance evaluation and validation by human observers, shows that the proposed method will be a useful tool in the evaluation of retrospectively acquired MRI images and the evaluation of noise reduction algorithms.

show abstract

“…However, the gradient-based index is advantageous for the SPR patterns [29]. The sharpness for focusing was used for light control in previous studies [15][16][17]30], the gradient-based index was considered for lighting, and the Tenenbaum gradient was finally chosen [31].…”

Section: Image Correction and Indexmentioning

confidence: 99%

“…The dimming level for maximizing the image quality was determined by iterating the simplex search method (SSM). Automatic color lighting was proposed in our previous studies; however, the focus was on non-repetitive patterns in a small area [17]. As such, they are not suitable for these FPD inspection processes.…”

Section: Introductionmentioning

confidence: 99%

Optimal Color Lighting for Scanning Images of Flat Panel Display using Simplex Search

Kim

Jin

et al. 2018

J. Imaging

Self Cite

View full text Add to dashboard Cite

A system for inspecting flat panel displays (FPDs) acquires scanning images using multiline charge-coupled device (CCD) cameras and industrial machine vision. Optical filters are currently installed in front of these inspection systems to obtain high-quality images. However, the combination of optical filters required is determined manually and by using empirical methods; this is referred to as passive color control. In this study, active color control is proposed for inspecting FPDs. This inspection scheme requires the scanning of images, which is achieved using a mixed color light source and a mixing algorithm. The light source utilizes high-power light emitting diodes (LEDs) of multiple colors and a communication port to dim their level. Mixed light illuminates an active-matrix organic light-emitting diode (AMOLED) panel after passing through a beam expander and after being shaped into a line beam. The image quality is then evaluated using the Tenenbaum gradient after intensity calibration of the scanning images. The dimming levels are determined using the simplex search method which maximizes the image quality. The color of the light was varied after every scan of an AMOLED panel, and the variation was iterated until the image quality approached a local maximization. The number of scans performed was less than 225, while the number of dimming level combinations was 2048 4 . The proposed method can reduce manual tasks in setting-up inspection machines, and hence is useful for the inspection machines in FPD processes.

show abstract

Robust Parameter Design of Derivative Optimization Methods for Image Acquisition Using a Color Mixer

Cited by 5 publications

References 27 publications

On-Machine Measurement for Surface Flatness of Transparent and Thin Film in Laser Ablation Process

On-Machine Measurement for Surface Flatness of Transparent and Thin Film in Laser Ablation Process

Local Indicators of Spatial Autocorrelation (LISA): Application to Blind Noise-Based Perceptual Quality Metric Index for Magnetic Resonance Images

Optimal Color Lighting for Scanning Images of Flat Panel Display using Simplex Search

Contact Info

Product

Resources

About