A real-time print-defect detection system for web offset printing

Shankar, N.G.; Ravi, Nitin; Zhong, Zhang

doi:10.1016/j.measurement.2008.10.012

Cited by 29 publications

(17 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Image feature extraction methods based on machine vision include: statistical analysis methods and frequency domain analysis methods. The main statistical methods for analyzing the gray value characteristics of the wear region image include: gray-level threshold method [14], edge detection [15,16,17], and histogram method [18]; analysis methods based on spatial frequency domain feature extraction include: Fourier transform [19], wavelet transform [20] [21] and homomorphic filtering [22]. Statistical analysis methods are widely used basic methods.…”

Section: Chinamentioning

confidence: 99%

Multi-Dimension Tool Wear State Assessment Criterion on the Spiral Edge of Milling Cutter

Tian¹,

Yang²

2021

Preprint

View full text Add to dashboard Cite

In the assessment of the tool wear state for the spiral edge of milling cutter based on machine vision, the traditional assessment criterion is often inaccurate due to the problem of information missing or incomplete especially near the tip area. In order to deal with this problem, different lighting-condition setting and additional non-image information compensation techniques are needed . In view of this, an integration tool wear detection method combined line laser edge detection and machine vision is proposed. Subsequently, the combined data acquirement experimental system is designed and built, which can simultaneously acquires two types of parameters: diameter and images under the same detection condition. Then, based on the above information, a multi-dimension series assessment criterion is proposed consisting of three dimensions index: The one-dimensional assessment index gives the average wear value of the spiral side, which mainly used as data ordination and characterizes the rule of tool wear degradation; the two-dimensional assessment index describes the contour of the wear region and calculates the area value, which can predict the change of the tool wear stage more precisely; the three-dimensional assessment index gives the 3D morphology by adding depth information within the wear region and quantified the volume of the worn-off part, which provides clues for early warning of the deterioration caused by the tool worn. Experiments proved that the multi-dimension series assessment criterion is helpful to reflect the trend of tool life and give a more accurate assessment of the tool wear state for the spiral edge of milling cutter.

show abstract

Section: Chinamentioning

confidence: 99%

Multi-Dimension Tool Wear State Assessment Criterion on the Spiral Edge of Milling Cutter

Tian¹,

Yang²

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…Pixel averaging does have its caveats [28], whilst removing noise, we may also lose some of the intrinsic print defects [29,30,31]. Print defects in currency are important during investigation when discriminating between individual printer.…”

Section: A Featuresmentioning

confidence: 99%

Currency security and forensics: a survey

Chambers

Yan

Garhwal

et al. 2014

Multimed Tools Appl

View full text Add to dashboard Cite

Abstract-By its definition, the word 'currency' refers to an agreed medium for exchange, a nation's currency is the formal medium enforced by the elected governing entity. Throughout history, issuers have faced one common threat: counterfeiting. Despite technological advancements, overcoming counterfeit production remains a distant future. Scientific determination of authenticity requires a deep understanding of the raw materials and manufacturing processes involved. This survey serves as a synthesis of the current literature to understand the technology and the mechanics involved in currency manufacture and security, whilst identifying gaps in the current literature. Ultimately, a robust currency is desired.

show abstract

“…The system can recognise defects, categorise them into one of 47 classes, including colour drift, and suggest actions for the operator to eliminate the cause of defect. Another image analysis-based defect detection tool, assisting the press operator in finding defect in the print and taking appropriate adjustments, was tested on a Flexo gravure printing press [16,17]. The system is supposed to be used on offset printing presses.…”

Section: Recent Developments In Automated Print Quality Assessmentmentioning

confidence: 99%