GB/T 18405-2008Micrographics -- ISO character and ISO test chart No.1 -- Description and use (English PDF)

Foreword

This standard is identical with ISO 446:2004 "Micrographics - ISO character and ISO test chart No. 1 and describes the use of" (In English).

This standard and ISO 446:2004 compared to modify the main editorial as follows.

--- Re-write the foreword;

--- Use the "standard" instead of "this International Standard";

--- Effective use of existing national standards instead of the corresponding international standard.

This standard replaces GB/T 18405-2001 "features characters and Micrographics ISO test chart No. 1 and its use." this standard and GB/T 18405-2001 compared to major technological changes are as follows.

--- With ISO 5-2:2001 "Photography - Density measurements - Part 2. Geometric conditions for transmission density", ISO 5-3:1995 "photography Density measurements - Part 3. Spectral conditions "and ISO 5-4:1995" Photography - Density measurements - Part 4. Geometric reflection density Conditions "and other normative references instead of GB/T 11500-1989" photographic transmission density measurement geometry ", GB/T 11501-1989 "spectral transmission density measurement photographic conditions" and GB/T 12822-1991 "photographic reflection density measurement geometry," and other regulations Normative references.

This Standard Document Imaging Technology by the National Standardization Technical Committee (SAC/TC86) and focal points.

This standard was drafted. National Information Technology Standardization Technical Committee Document Imaging a club.

Introduction

In addition to the diffusion transfer method, the replication process will cause most of the image quality is reduced. This severely reduces the quality to a certain extent After the degree, it will make the information unreadable. If the readability of poor quality, long reading can also cause visual fatigue.

Readability of the image by measuring the limiting resolution that is the ability to distinguish lines in different directions to be evaluated. However, the limiting resolution Rate image quality level is not sufficient to guarantee the state of comfortable reading, does not guarantee long time to read without cause visual fatigue.

Thus, the need to find a practical evaluation criteria. One kind of the font used in the printing industry similar to the regular characters that is ISO character satisfies these requirements, because of its contours and details identifying it without difficulty.

The main practical uses ISO character following experimental performance-based.

a) If a particular replication process with a certain degree of ISO characters generate a recognizable image from a group, it can be assumed the same replication process will be able to obtain satisfactory images from the printed text is almost the same size font, especially for reading Were sufficiently clear, easy to read, and does not cause fatigue of the image;

b) In general, by different observers to identify the limits of the same group of distinguished ISO characters will produce consistent results.

GB/T 18405-2008/ISO 446:2004 Micrographics - ISO character and ISO No. 1 Characteristics of the test chart and use

1 Scope

This standard specifies the characteristics of black and white characters and features ISO ISO test chart No. 1 and its use.

This standard applies to the quality control reference microfilm images generated by the system, and using the system made microform potential readability.

2 Normative references

The following documents contain provisions which, through reference in this standard and become the standard terms. For dated references, subsequent Amendments (not including errata content) or revisions do not apply to this standard, however, encourage the parties in accordance with this standard research agreement Study whether the latest versions of these documents. For undated reference documents, the latest versions apply to this standard.

GB/T 321-2005 priority number and priority number system (ISO 3. 1973, IDT) GB/T 1543-2005 Paper and paperboard opacity (paper backing) measurement (diffuse reflectance method) (ISO 2471:1998, MOD) GB/T 6159.1-2003 Micrographics - Vocabulary - Part 1. General terms (ISO 6196-1:1993, MOD) GB/T 6159.3-2003 Micrographics - Vocabulary - Part 3. film processing (ISO 6196-3:1997, MOD) GB/T 6159.4-2003 Micrographics - Vocabulary - Part 4. Materials and packaging (ISO 6196-4:1998, MOD) GB/T 6159.5-2000 Micrographics - Vocabulary Part V. image quality, readability and inspection (Eqv ISO 6196-5. 1987) GB/T 6159.6-2003 Micrographics - Vocabulary - Part 6. Equipment (ISO 6196-6:1993, MOD) GB/T 6159.22-2000 Micrographics - Vocabulary Part II. and methods of recording images (eqv ISO 6196-2:1993) GB/T 6160-2003 Micrographics source file first generation silver - gelatin microforms density specifications and methods of measurement (ISO 6200:1999, MOD) ISO 5-2:2001 Photography - Density measurements - Part 2. Geometric conditions for transmission density ISO 5-3:1995 Photography - Density measurements - Part 3. Spectral conditions ISO 5-4:1995 Photography - Density measurements - Part 4. Geometric conditions for reflection density

3 Terms and Definitions

GB/T 6159.1-2003, GB/T 6159.3-2003, GB/T 6159.4-2003, GB/T 6159.5-2000, GB/T 6159.6-Terms and definitions 2003 and GB/T 6159.22-2000 established apply to this standard.

Description and use 4 ISO characters