Remove fingerprints hands visa.
Us for several years requested to remove fingerprints hands visa, most countries in the US and Canada.
ypically prints fingers should fill in Form FD-258, which we have available, you can download it from the site and print FBR In detail by or through the Internet. It is necessary to check the person for prosecution in the country.
All existing accounting system fingerprint work on common principles.
The main stages of their work are:
1. Scan object (or daktilokarty, or track), resulting in the formation bitmap grayscale.
2. Filter the resulting image. Generally, the track mark – is smeared fragment layout is an expert in a certain way is difficult.
Traditionally used as a filter for the separation threshold is given by fixed (limit) value, and if the tone of the image element (Pixel) does not exceed the limit, the lower limit given element value, otherwise the – top. In a very blurry places you can use division to the threshold in stages (steps) that can provide informative parts of the image.
3. Arrange the received image pixels in tone -klastery groups, ie clustering. In this case, if the pixel neighborhood is not sufficient (critical) number of pixels of the same tone, it becomes important that matches the tone of his surroundings. Due to such processing bitmap image of the fingerprint filtered random noise.
4. Construction skeleton print, determine the specific points and integrated its characteristics. Originally defined specific point – the point of beginning papillary lines, finite et al., Which are the points of abrupt change in behavior papillary lines. From each of these points in the direction of papillary line built vector (usually on the first three clusters). The limit is linked clusters skeleton print. Comparison of skeleton lines pattern makes it possible to determine the location and orientation of integrated features – loops, curls.
5. Calculate the density on some systems papillary lines on fixed segment, often in areas with a given angle; angles between vectors that connect specific points, and so on. This work automated system with the introduction of a print finishes.
6. Activities expert – is removed or changed information markup automated fingerprint system.
Fingerprint identification based on fingerprint cards available desyatipaltsevy system is as follows:
- Provision of integrated fingerprint with the same characteristics.
- The relevant group should be compared with existing daktilokarty by singular points (ie the elements of a vector field). This is compared point location and direction of the respective vector. With daktilokarty arranged according to the number of matches.
- Analyzes the density of papillary lines overlap skeletons and more.
- Is displayed on the monitor image and imprint study relevant daktilokarty.
