The BSS AntiCopy^® application has been developed to protect printed images from photocopying (Xeroxing). The protection algorithm is based on the use of special micropatterns (rasters) that are applied to process separate areas of the image to be protected. As an initial data for processing they may take a solid background, a Grayscale image or a color image in the RGB or CMYK formats.

The source image is processed in a way not altering the view (brightness, contrast ratio, color hue) of the printed copy in comparison with the source image (a latent image being added). In other words, the integral density of the source image is similar to the integral density of the processed image.

The area to be marked with latent image will be indicated by the user interactively. The latent image itself will be selected by the user from the library (inscriptions: "COPY", "VOID", etc.), or submitted by the user in a form of a graphic file.

The micropattern will be created by the user in a special editor application. Aside from common rasters (lines, various types of dots) the user will be provided with a capability to create own micropatterns.

The result will be saved in a graphic file in the TIFF or EPS format.

The algorithms integrated into the software allow implementing the following methods of insertion of latent images that will be visible on photocopies:

1. Use of various kinds of hatches by multidirectional lines and of special rasters superimposed at different angles. As a result, at photocopying (Xeroxing) of such patterns a specific picture (a moire pattern) appears on the photocopy being absent on the original copy.
2. Copiers reproduce vertical and horizontal lines in different ways. An advantage can be taken of this particularity in the following manner: a part of the image is hatched with horizontal lines, another part being hatched with vertical ones. Lines in this instance can be replaced by oblong rectangles or ellipses. It is to note that this method will not be advisable if the protected image is turned at, for example, 45 degrees at photocopying.
3. As a rule, the resolution of copying machines is rather low. This fact gives life to the method applying rasters with different ruling, as well as combinations of fields containing large and small elements. In this case the copying machine will successfully reproduce large elements failing to correctly reproduce small ones.
4. The next protection method is based on a deficiency of all copiers: they are not capable to correctly reproduce halftones. A part of the image is then rendered with thin solid lines, another part being rendered with halftone wider lines.

All the methods enumerated above except for the last one, are applicable in traditional offset printing. For digital printing all the methods are good apart from the third one due to low resolution of printer.

In practice, all the methods described above require preliminary calibration of the printing process. That is conditioned by the fact that the use of different rasters leads to differences of halftones of the source image presentation. Thus, for example, a printing of 20% grey copies with different parameters of rasterizing will show that sight perception of the copies is different: one copy will be darker, the other one brighter. The main task of calibration is, therefore, elimination of visible differences in reproduction of halftones.

BSS AntiCopy^® runs on Microsoft^® Windows^® 2000/XP/Vista PC-platforms.