Overview
ISO 11698-1:2000 - Micrographics: Characteristics of the test images defines standardized test images for evaluating the image quality produced by aperture card scanners and microfilm capture systems. Part 1 specifies the layout, content and purposes of a set of test microimages (types 1–6) used to measure centring, scaling, resolving power, line reproduction, focus and character legibility. These controlled test images form the basis for objective and repeatable image-quality assessment of aperture card scanning workflows.
Key topics and requirements
- Test image types (1–6): Each type targets a specific quality attribute:
- Type 1 - centring, scaling, capture size, line straightness, orthogonality and uniformity of line width (seven variants for common sheet sizes A0–A4).
- Type 2 - resolving power (Pestrecov stars and ISO No. 2 chart sections at multiple locations: centre and corners).
- Type 3 - line-width performance across different thicknesses (patterns based on ISO 6428 line series).
- Type 4 - focus assessment using pattern pairs with increasing spatial frequency (frequencies specified from ~21.5 to 111 line pairs/mm).
- Type 5 - character legibility with graded character sizes and alphanumeric lines.
- Type 6 (user / Annex A) - user-prepared technical drawing target for subjective, real-world assessment.
- Design and construction: Test cards are defined as aperture cards with inserted microimages or film the size of an aperture card; recommended film thickness and reduction ratios are specified where applicable.
- Repeatability: Standardized patterns (Pestrecov stars, ISO chart sections, character blocks) enable consistent measurement across different scanners and test labs.
- Normative references: Links to related vocabularies and procedures such as ISO 3272-1, ISO 6196 series, ISO 6428 and ISO 12651 are integral for correct interpretation and use.
Applications and who uses it
- Scanner manufacturers and OEMs use ISO 11698-1 to design, calibrate and validate aperture card scanning systems.
- Quality engineers and test labs apply the test images for acceptance testing, calibration and benchmarking of image capture performance.
- Document conversion service providers and archives rely on the standard to verify fidelity when digitizing technical drawings and engineering aperture cards for CAD and electronic information systems.
- Facilities managing long-term microfilm archives use the standard to check scanner focus, resolution and legibility before mass digitization.
Related standards
- ISO 11698-2 (Quality criteria and control) - describes procedures for using the test images.
- Normative references: ISO 3272-1, ISO 6196-1/4/5/6, ISO 6428, ISO 12651 - for filming procedures, vocabulary, line series and technical drawing requirements.
Keywords: ISO 11698-1, aperture card scanners, micrographics, test images, image quality, resolving power, Pestrecov star, line width, scanner focus, character legibility.