Overview
ISO 14648-1:2001 specifies the characteristics of an electronically generated software test target for quality control of COM (Computer Output Microfilm) recorder systems that generate images using a single internal display system. The standard defines test-target components to check and maintain image quality independently of the recording technology (laser scanner, CRT, LED, etc.). It is Part 1 of the ISO 14648 series and pairs with Part 2 (method of use).
Key topics and technical requirements
- Software test target types: Two targets are defined:
- Target 1 for COM systems with limited bitmap memory (simpler set of components).
- Target 2 for systems with greater bitmap capabilities (more complex components).
- Dot spacing and overlap: Dot centre-to-centre spacing relates to original document resolution (example: 240 dpi → 0.0042 in full size). The dot diameter/spacing overlap ratio typically ranges 1.3–1.5 so successive dots form smooth lines.
- Grid layout and borders: A grid of 132 columns × 64 rows is specified with full-size text dimensions of 335.3 mm × 270.9 mm. A single-dot-width border encloses the grid.
- Test charts and patterns: Each test chart contains five patterns comprised of two groups of six lines and five spaces, with specific placement rules. Target 1 contains two charts; Target 2 contains six.
- Density measuring areas: Three density patches (solid, clear, cross-hatched) sized 40×24 cells and enclosed by a two-dot-width box; exact grid coordinates are defined for reproducible density checks.
- Diagonal lines and measuring scales: Diagonal line positions and two measuring scales (horizontal and vertical) are specified so microimage lengths (e.g., 6.35 mm at defined reductions) can be verified.
- Character legibility areas and fonts: Primary legibility tests use upper-case letters E, H, N at specified pitches; an alternative font area is reserved for application-specific characters.
- Title and identification area: Reserved grid area for test-target identification and metadata.
Applications and users
ISO 14648-1 is used to design and generate electronic test targets for:
- COM recorder manufacturers validating device output and dot/sharpness behavior.
- Quality engineers and technicians performing routine image quality control on microfilm production systems.
- Document-imaging service providers and archives ensuring consistent microfilm legibility and density.
- Test and calibration labs that verify COM recorder conformity and system performance over time.
Practical benefits include consistent, repeatable image-quality checks, easier fault diagnosis (focus, dot overlap, density), and objective baselines for maintenance.
Related standards
Open preview (PDF)Micrographics — Quality control of COM recorders that generate images using a single internal display system — Part 1: Characteristics of the software test target
