Digital Image Quality Analysis and Evaluation Research
With the advancement of digital technology, the work of the printing industry in obtaining images has been fully digitized. Due to the fact that traditional physicochemical imaging systems such as film and film are expensive, narrow in application, and low in sales, manufacturers have no longer introduced corresponding high-quality roller scanners and large-format flatbed scanners. Instead, they are lightweight and inexpensive digital cameras. The combination of digital back and middle flat panel scanners is more flexible and applicable in practical applications in the printing industry.
We are a big printing company in Shenzhen China . We offer all book publications, color advertising pictures, hardcover album, packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: 860681365@qq.com
In today's mobile phones, digital cameras with millions of pixels are beginning to enter the billion-pixel era. Digital imaging will no doubt become the mainstream. The quality of digital imaging determines the quality of printed copy images from the source. . The acquisition of digital images and the replication process are in urgent need of establishing standards so that the quality of printed digital images can be linearly controlled, measured and evaluated.
Image quality evaluation method
The evaluation of the quality of printed matter is the core evaluation criterion for the quality of printing. The evaluation methods for traditional printed image quality are based on subjective evaluation methods and supplemented by objective evaluation. The main approach of subjective evaluation is to visualize under the observation environment of standard light sources; the objective evaluation method is to use auxiliary instrument test data, and the objective evaluation methods for quality control in print production are generally divided into three types:
1. Density method. The CMYK values are read using the Konica Minolta FD-7 Densitometer or the X-Rite exact densitometer. The color of the index points in the sample record screen is recorded, and the data is recorded in the database for numerical analysis, graphing, and scoring.
2. Spectrophotometry. Using X-Rite XRite intellitrax or Konica Minolta FD-9 and other automatic test equipment to read the print Lab values, numerical analysis scores. The Intellitrax has a larger measuring range and does not destroy the test sample, but the FD-9 has a smaller format.
3. Online detection (image method). A CCD camera captures the image and analyzes the RGB color values of the printed block to determine and analyze it. This method is mainly used to detect quality problems in the production process. Because the test instrument and software can work in continuous steady state, it is more reliable than manual detection.
Because the chromaticity and density test principle is to test the combined effect of a color patch area and sometimes cannot reflect the flaws in the details of the product, the quality evaluation method based on image test is widely used, but the corresponding measurement equipment is generally expensive, printing The industry also lacks sufficient depth of research and applications.
The evaluation of print quality is still based on subjective evaluation as the highest principle, even if subjective evaluation cannot meet the quality control of mass production.
Imatest Image Quality Analysis Software
Imatest software is a digital image quality analysis software developed by Imatest Corporation based on MATLAB platform. It has become a mainstream tool for digital image quality analysis. The applicable industries include cameras, cameras, optical devices, and printing and packaging.
Among them, Imatest master software is used for static image analysis and can run on Windows, Mac, and Linux platforms.
Imatest IT (Industrial Testing) is used for automatic image detection and online inspection of production lines. It calls the image analysis function and supports C/C++, Python, NET c# and other mainstream programming language calls.
The printing industry can use this tool widely used by upstream digital camera R&D manufacturers for image analysis.
Imatest master software image analysis module for the printing industry includes:
ColorChecker for analyzing image color; Stepchart for analyzing tone (dynamic response range);
Uniformity for analysis of uniformity; Wedge for defect detection;
The Multichart module can analyze charts such as IT8.7 commonly used for print color management.
Combined with colorimeters and densitometers, automated analysis of multiple color data can be accomplished.
Digital imaging is gradually becoming the mainstream method for image acquisition in the printing industry. The quality of the image is determined comprehensively by the lens, light source, shooting system, and digital image processing software. The existing color management experience in the printing industry cannot simply cover the imaging quality evaluation of digital imaging devices (such as HDR wide dynamic images).
The acquisition process of digital images in the printing industry lacks a reliable industry basis, especially for the copying of artworks such as murals. When we rely on digital cameras to obtain images, this shortcoming becomes prominent. The printing industry also needs to explore more methods for copying and evaluating digital images. The image quality evaluation can be secondary developed with Imatest and other software, making the quality evaluation of digital images in line with international standards and the actual application of the printing industry.
Digital imaging is gradually becoming the mainstream method for image acquisition in the printing industry. The quality of the image is determined comprehensively by the lens, light source, shooting system, and digital image processing software. The existing color management experience in the printing industry cannot simply cover the imaging quality evaluation of digital imaging devices (such as HDR wide dynamic images). The acquisition process of digital images in the printing industry lacks a reliable industry basis, especially for the copying of artworks such as murals. When we rely on digital cameras to obtain images, this shortcoming becomes prominent. The printing industry also needs to explore more methods for copying and evaluating digital images. The image quality evaluation can be secondary developed with Imatest and other software, making the quality evaluation of digital images in line with international standards and the actual application of the printing industry.