DIN 33872-4:2010-12

The DIN 33872 standard series is directed at both manufacturers of output devices and end users for whom colour output properties are an important criterion in context with colour reproduction systems (digital, analog). The colour reproduction system includes, for example, the computer operating system and the application software for an analog output of a digital file on printers; multifunctional devices; displays; data projectors. The standard series describes methods for specification of the relative colour reproduction of the output by defined YES/NO-criteria and applies to colour reproduction systems "digital, analog". The goal is the visual assessment of the output properties of these colour reproduction systems. Every part of the standard includes special DIN test charts which are used as digital test files in the formats PostScript (PS) and Adobe Acrobat (PDF) for colorimetric specification (DIN 33872-1) and visual assessment of the output (DIN 33872, Part 2 to Part 6), for instance, with printer and monitor systems. DIN 33872 "Information technology - Office machines - Method of specifying colour reproduction with YES/NO criteria" consists of the following parts: - Part 1: Classification, terms and principles - Part 2: Test charts for output properties - Testing of discriminability of 5 and 16 step colour series - Part 3: Test charts for output properties - Testing of equality for four equivalent grey definitions and discriminability of the 16 grey steps - Part 4: Test charts for output properties - Testing of equality for two equivalent colour definitions with 5 and 16 step colour series - Part 5: Test charts for output properties - Testing of elementary hue agreement and hue discriminability - Part 6: Test charts for output properties - Testing of the equivalent spacing and of the regular chromatic spacing The basis for this standard is the DIN 33866 standard series with specifications for the establishment and application of digital and analog test charts for image reproduction of the colour devices copier, printer, monitor and scanner. The informative Annex A of DIN 33872-1 includes a table overview which lists the relationships of standards and technical reports, their applications and if they are suitable for colour reproduction. This DIN 33872 standard series only contains the colour reproduction system "digital - analog" and determines the colour properties of the analog output with digital test files, for example, with printer and monitor systems. The test files according to DIN 33872 use different PostScript operators, for example, setgray, setrgbcolor and setcmykcolor and are available in the PostScript (PS) Format and in the Portable Document Format (PDF). The w-, rgb- and cmyn-data of these various PS operators are used to generate the colour output. Colorimetry determines the CIELAB device data and is used for CIELAB linearization of the device output. The colorimetric specification of the DIN 33872 standard series is similar to the specification in accordance with ISO/IEC 15775. ISO/IEC 15775 defines a colorimetric output tolerance of 3 CIELAB. Many output devices reach the standard deviation of 1 CIELAB. This corresponds to the visual discriminability. Output colour differences of up to 30 CIELAB may be caused, amongst others, by the following sources: computer operating system, application software, device drivers, printer software and the type of light used during colour assessment. The output of the test files according to DIN 33872-1 to -6 results in device system colours which are produced by the interaction of the five sources. The output is visually assessed and/or colorimetrically specified. Thus, it can be established if the output properties desired by the users are met or not. This does not include quality evaluation of the device systems. The property "equidistant output colour series" may be important for many users; for others it may be less important. If a user requires output properties which are specified in DIN 33872, Parts 2 to 6, there is a large number of device systems which meet these requirements or which may meet these requirements by suitable settings. The DIN test is advantageous for both the user and the device manufacturer. If the device system colours change during output, the possible source of the change can often be identified and the output properties of the corresponding medium (for example, printer and monitor) can be influenced therewith. The test may contribute to a stable storage and output of digital colour data for the user. The user receives support in selecting computer operating system, application data device, device, device driver and illumination according to the user's wishes. A linearized output is the prerequisite for safe identification of defined colour differences which are included in the rgb- or cmy-test files according to DIN 33872-1 to -6. Some printers produce grey colours, especially in images, not with the printing ink black N (N=noir), but with 3-colour overprint and thus, output costs are 3 times higher. Often, a higher CIELAB colourfulness with respect to the linearized output is produced. Thus, the standard does not only comply with the ergonomic visual requirements for, for example, linearized output according to DIN EN ISO 9241-306 on displays, but is also cost-effective when the linearization and a suitable colour separation for printers are applied. ISO/IEC TR 24705 and a publication of the BAM with regard to the DIN 33872 standard series (Colorimetric supplement) which can be downloaded from the BAM, the Federal Institute for Material Testing Web page (www.ps.bam.de/D33872-A.PDF), are other publications to related topics. The Committee responsible for this standard is NA 043-01-28 AA "Bürogeräte" ("Office equipment") at DIN.