The scanners, even those monochromatic, acquiring a document perform in fact a measurement of the amount of light reflected from the surface of the sheet, obtaining by electronic circuits usually a value between 0 and 255. Having to return an image in gray-scale, is returned precisely this value, but having to return a monochrome image, it must be set a threshold value, below which the point is considered black, above is considered white. The selection of this threshold is very delicate operation because according to it you can get readable documents or too light or too dark. If an image is too light or too dark, it may be difficult to read the data contained in it, which was quite serious if you do not notice the problem immediately, but only when it is too late, that is when you need the document, but the original paper is no longer available. But the biggest problem is the fact that, more often than not just imagine, there is no possibility that a threshold value, whatever it is, makes the image readable in all its parts. Is to solve these problems that were born the tools of thresholding dinamico. In essence, instead of using a threshold value valid for the whole image, is used a threshold value specifically for each image point, calculated on the basis of different algorithms, more or less advanced. With this system it is possible to avoid losing written extremely bright light background, or to turn into black spots lettering on dark background very dark.

This technology is probably one of the most complex and most problematic is to identify both the type of dynamic thresholding most appropriate to their documents, and any required parameters. However, the latest news in this field allow to not have to set any parameters so that the same system to analyze the image and determine which parameters are most appropriate to process it in the best way.