This section explains major differences in verification between ISO/IEC 15415 and ISO/IEC TR 29158 (AIM DPM-1-2006).
How the binary threshold is defined
Different methods are employed to define the threshold used to judge whether a cell is black or white.
Specifically, the following points are different.
ISO/IEC 15415 takes an intermediate value between the highest and lowest intensities in the symbol as the threshold value.
ISO/IEC TR29158 (AIM DPM-1-2006)
ISO/IEC TR 29158 (AIM DPM-1-2006) takes the intensity with the minimum total of dispersed intensities of black cells and white cells in the symbol as the threshold value.
The average intensity of black cells and that of white cells in the graph above are derived with a set threshold value and used for evaluation of cell contrast and the like.
|ISO/IEC 15415||Verification standard for 2D codes printed on labels|
|ISO/IEC TR 29158 (AIM DPM-1-2006)||Verification standard for 2D codes directly marked on products|