General Fingerprint Rules Rules in Selection of Delta

General Fingerprint Rules

Rules in Selection of Delta may not be located at the bifurcation not opening toward the core.

When a pattern shows a series of bifurcating ridges all opening toward the core at the point of divergence of the type lines, the bifurcation nearest the core is chosen as delta.

When there is a choice between a bifurcation and another type of delta, equally close to the point of divergence or equidistant from that point, a bifurcation is selected.

If a ridge emanates from (a) or above (b) the point of divergence of they type lines and in the direction toward the core, the delta is located at the end of such ridge nearer the point of divergence.

If a ridge enters the pattern area from a point below the divergence between the type lines, the delta is located at the end nearer the core.

If a ridge is entirely within the pattern area, the delta is located at the end nearer the point of divergence.

If two different ridge formations, excluding the bifurcations, appear and are equidistant to the diverging point the matter of selection is based upon the following conditions: In case of long and short ridge, the former is chosen for predominating the latter. In case where a short and ridge eye are present, the former is selected for predominating the latter. In case of a ridge eye and a very short ridge, the former is selected. In case of a very short ridge and a dot ridge, utilize the former.

Rules in Selection of Core If the innermost re-curving ridge or looping ridge does not contain any ending ridge inside it, the core is located on the shoulder of such re-curving ridge farther from delta.

When the innermost looping or re-curving ridge contains a single ending ridge or rod rising as high or above the shoulder line, the core is located at the end or tip of such ending ridge.

When the innermost re-curving ridge contains an uneven number of ending ridges or rods rising as high or above the shoulder line the said re-curving ridge, whether it touches the looping ridge or not.

When the innermost re-curving contains an even number of ridge or rods rising as high as or above the shoulder line, the core is located upon the end of the farther one of the two center ridges or rods. The two center ridges are treated as though they were connected by a re-curving ridge.

If the innermost looping ridge is connected at right angle between its shoulders by an appendage, the innermost looping ridge is destroyed and the uninvolved loop immediately outside of it shall be considered as the innermost loop and shall be used to determine the location of the core.

If there are two distinct loops in the center of the innermost looping ridge, which run side by side, the recurving ridges are considered as one with the two ending ridges and the core is established at the shoulder of the one that is farther from the delta.

In the event two distinct loops in the center of the innermost looping ridge intersects below the shoulder line, the two re-curving ridges are treated as as one with two ending ridges and the core is located at the first or nearer shoulder of a second of second loop or at the innermost ending ridge farther from the delta.

If two distinct loops in the center of innermost looping ridge intersect above the shoulder line, the two recurving/ looping ridges are treated as one with two ending ridges and the core is located at the farther shoulder of the first loop or at the innermost ending ridge farther from the delta.

When two distinct loops intersect in the shoulder line, the point of intersection is considered as the core.