Overview - ISO 11928-1:2000 (Micrographics, Test Frame Characteristics)
ISO 11928-1:2000 specifies the characteristics of test frames used to evaluate the image quality of microforms produced by graphic COM recorders. The standard applies to COM recorders that output alphanumeric and graphic images onto black-and-white film. It defines test-frame layouts and measurable features to assess frame size, linearity, resolution, legibility, density, radial recording, curved-line reproduction, and character display/rotation.
Key topics and technical requirements
The standard focuses on precise, repeatable test patterns (test frames) to support quality control of microforms:
- Frame geometry and positioning
- Rectangular grid matching the recorder’s largest image size.
- Grid lines at intervals of one-eighth of the long axis from the frame centre, plus diagonals connecting corners and midpoints.
- Resolution, legibility and density
- Patterns of five-line groups with identifying letters to locate the point of resolution failure.
- Groups of lower‑case letter “e” in varying sizes, each identified by a numeral, to determine legibility limits.
- A designated area for measuring minimum optical density (may be separate).
- Radial recording
- Parallel pairs of radial lines spaced at 22.5°; separation in each pair equals line thickness - used to check radial fidelity.
- Curved-line reproduction
- Concentric circles with radial lines at 45°; outer circles drawn with double lines to assess curvature integrity.
- Character display and rotation
- Lines of characters at available character sizes and small rotated character samples in frame corners to test character rendering and rotation.
Normative references and context:
- Uses terminology from ISO 6196-7:1992 (computer micrographics vocabulary).
- Intended to help COM outputs be comparable with conventional microfilm standards such as ISO 3272-1/2/3.
Applications - who uses ISO 11928-1
- Manufacturers of graphic COM recorders and film output devices for design verification and product development.
- Quality-control engineers and test labs establishing routine image-quality checks.
- Archival and records managers ensuring COM-generated microforms meet archival standards and interoperate with microfilm systems.
- Document imaging professionals integrating COM outputs into microfilm-based workflows (e.g., aperture cards).
Related standards
- ISO 11928-2 (Quality criteria and control) - companion part addressing acceptance criteria.
- ISO 6196-7 (vocabulary for computer micrographics) - normative reference.
- ISO 3272 series - relevant microfilm image quality benchmarks.
Keywords: ISO 11928-1, micrographics, COM recorders, test frames, image quality, microforms, resolution, legibility, density, radial recording, character rotation.