BS ISO/IEC 16480:2015 pdf download-Information technology — Automatic identification and data capture techniques — Reading and display of ORM by mobile devices.
5.1.4 Capturing an image To capture an image for quality analysis, use a verification device that has its lights turned off or which does not have auxiliary lighting. The image should be taken in ambient lighting conditions. The image time should be such that the white areas reach between 70 and 85 percent of image sensor saturation. 5.1.5 Grading an image 5.1.5.1 Relation to 15415 and 15416 For 2D bar code symbol quality analysis, the methods of ISO/IEC 15415 shall be used with the exception that R max is set to 90 % and Symbol Contrast is not graded or reported. A synthetic aperture of 0,38 mm (15 mils) shall be used to process the image to produce the reference gray scale image. The aperture size used for grading is 0,25 mm (10 mils). While less common, if the symbol is a linear bar code, then the methods of ISO/IEC 15416 shall be used except that the scan reflectance profile set is produced in software from an image using an aperture size that is 80 % of the symbol X-dimension with R max set to 90 % and Symbol Contrast not graded or reported.
5.1.5.3 Z-dimension In addition, the Z-dimension of the symbol is calculated and reported. A symbol is non-conforming if the measured Z-dimension is less than 0,35 mm (0,014 in) or greater than 0,65 mm (0,026 in). This allows a small tolerance on the measurement of the limits set in 5.1.3. 5.1.5.4 Quiet Zone Noise (QZN) Evaluate the quiet zone noise (QZN) by calculating the variation in the quiet zone area as a ratio to the contrast in the symbol area. For symbologies without a defined QZ, QZN = 0. In the reference gray-scale image, set four test lines which are the lesser of 0,5 of the QZ or two modules away from the symbol side forming a perimeter. For each test line, find the difference between the average of the lightest 10 % and the average of the darkest 10 % of the values along those lines. Navg is the largest of the differences found in any of the four test lines. In the reference gray-scale image of the symbol area (excluding quiet zones), select the darkest 10 % and the lightest 10 % of the values. Cavg is the difference between the average of the selected light values and the average of the selected dark values.