ISO IEC 13660 pdf download.Information technology – Office equipment – Measurement of image quality attributes for hardcopy output – Binary monochrome text and graphic images
This International Standard specifies device-independent image quality attributes, measurement methods, and analytical procedures to describe the quality of output images from hardcopy devices. This International Standard is applicable to human-readable documents composed of binary monochrome images produced from impact printers, non-impact printers, and copiers. The attributes, methods, and procedures rely on intrinsic properties of the image. Targets or reference images are not required. The International Standard is not applicable to images on media other than hardcopy (e.g. images on a VDT) or to images that are intended to be machine readable only (e.g. bar codes). This International Standard is not intended to apply to pictorial art. It is optimized for black colourant forming the image on a white substrate; it is not intended to be used for dropped out or reversed type or for transparencies. The evaluation of an image with any other colour of colourant or substrate will be sensitive to changes in illumination. In this case, the procedures of this International Standard may not be applicable and should be used with caution.
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply. The image quality attributes themselves are defined in Clause 5. binary- any system based on exactly two possible values, such as 0/1 or blaclúwhite. binary image- an image with only two fundamental tones: the substrate and the colourant. boundary- the region of an edge within which the reflectance factor makes the transition from 10% to 90% of the difference between image and substrate reflectance factors. See also threshold contour. character image- a specific physical representation of a character glyph. colourant- the material used to make an image visible. In copying and electronic printing, the two main colourants are dye and pigment. density, optical- log1 O (l/ß), where ß is the reflectance factor, measured according with O/45-degree geometry, Illuminant A, and IS0 visual density calibration. dictortion- undesired change in the shape of an image. edge threchold- the points in the gradients of an edge that define the location of the edge. This is the threshold contour corresponding to ß6, for the ROI. See also threshold contour. gradient, edge- the relative reflectance value gradient along a line normal to the edge of an image segment. hardcopy- a document on a substrate.human-readable- designed to be interpreted by a standard human viewer. image element- a single, evidently intentional, object not connected to other objects. image segment- a collection of image elements that are treated as a unit. inner boundary edge- the point in the gradient of an edge that is at 90% of the transition from the substrate reflectance factor to the image reflectance factor: ß, , = ßmax-900/o(ßmax – ßmin). I line width- width of the line measured normal to the line from edge threshold to edge threshold. monochrome image- an image in one colour or shades of one hue. nominal- a value used as a reference value. This value is obtained by assumption, by calculation, or by some other means and then treated as the actual, intended value. normal edge profile- the reflectance factor gradient along a line normal to the edge of an image segment. outer boundary edge- the point in the gradient of an edge that is at 1 0% of the transition from the substrate reflectance factor to the image reflectance factor: ß,, = ßmax-lO%(ßmax – &in). page- a collection of text, graphics, and other image objects intended to be printed on one side of a sheet of hardcopy. I pixel- a contraction of the term “picture element”; the smallest geometric unit of information in a digital representation of an image. pceudorandom- a sequence which is generated by a predictable process, but which has all the measurable properties of a truly random sequence that are required for a particular application.