JPH08161487A - Method for identifying person by sweat gland of finger - Google Patents

Abstract

PURPOSE: To identify a person by using a sweat gland of a finger by counting number of picture elements of each group in a labelling image, eliminating groups whose picture element number is a prescribed number or over and comparing the number of left groups after the elimination of groups in a prescribed area of a fingerprint with a number registered in advance so as to take notice of a sweat gland image having been handled as a noise in a conventional method. CONSTITUTION: A received image is received by a image processing section IPU via a local bus LB and binarized. Thinning processing is applied to the binarized image and labelling processing is applied to the image subjected to thinning processing. Then number of picture elements of each group in the labelling image is counted by a CPU. Then the labelling image whose picture element number is a prescribed number or over is eliminated. That is, when number of the picture elements is a prescribed number or below, the image is regarded as a sweat gland, and conversely when number of the picture elements is a prescribed number or over, the image is regarded as a recessed part between skin edges of a fingerprint, then the sweat gland only is left and the recessed part is eliminated. Then number of sweat glands of a prescribed area is counted and the count is compared with number of sweat glands of a concerned person registered in advance and whether or not the difference is within a permissible range is discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for identifying an individual by a sweat gland of a finger when identifying a person based on information on the finger.

[0002]

2. Description of the Related Art When identifying an individual, a fingerprint is effective information, and for example, the individual is identified based on the positions of ridges and characteristic points of the fingerprint, pattern matching and the like. However, in these methods, the sweat gland image input together with the ridge image and the like is treated as noise, and the method of eliminating the sweat gland image is the mainstream, and the method of effectively using the sweat gland image to identify a person is The reality is that it does not exist.

[0003]

SUMMARY OF THE INVENTION The present invention was devised to solve such conventional problems, and pays attention to a sweat gland image that has been conventionally treated as noise, and provides a personal identification method based on a sweat gland of a finger. The purpose is to provide.

[0004]

According to a personal identification method by a sweat gland of a finger according to the present invention, a fingerprint image is inputted and binarized,
The binarized image is thinned and labeled to count the number of pixels in each group in the labeled image, and the groups having a predetermined number of pixels or more are erased as recesses between the fingerprint ridges, and the above-mentioned areas in the predetermined area of the fingerprint are deleted. The group remaining after the depression is erased is defined as a sweat gland, and the number is compared with the number registered in advance to identify an individual.

[0005]

In the individual identifying method using the sweat glands of the finger according to the present invention, since the fingerprint image is input and the image is binarized, the ridge portion of the fingerprint and the recess portion between the sweat gland portion and the ridge of the fingerprint can be identified. Since the binarized image is thinned and labeled to count the number of pixels in each group, and the groups having a predetermined number of pixels or more can be erased as ridge recesses, only sweat glands can be extracted.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of a method for identifying an individual by means of a sweat gland of a finger according to the present invention will be described with reference to the drawings. FIG. 1 is a flowchart for carrying out the present invention, and FIG. 4 is a block diagram of an apparatus for carrying out the present invention. The present apparatus includes, for example, a central processing unit CPU, an image processing unit IPU, and an image memory I.
Central processing unit CPU, image processing unit IPU
The image memory IM and the image memory IM are connected by a system bus SB, and the image processing unit IPU and the image memory IM are connected by a local bus LB.

First, a fingerprint image touching the detection surface is input by an input device (not shown) (step 1-1), and the input image is aligned with the registered data registered in advance (step 1- 2). The registered input image is registered in the image memory IM (step 1-3), and the registered input image is input to the image processing unit I via the local bus LB.
It is taken into the PU and binarized as shown in FIG. 2 (step 1-4). This separates the ridges of the fingerprint and the sweat glands of the fingerprint and the depressions between the ridges.

Next, a thinning process is applied to this binary image (step 1-5). As a result of the thinning, the continuity of the recesses between the ridges is maintained as shown in FIG. 3, but when individual sweat glands are thinned, most of them are close to the arc starting point. The image is composed of individual pixels. Next, a labeling process is applied to this thinned image (step 1-6).

The central processing unit CPU counts the number of pixels in each group in the labeled image (step 1-
7). In this case, the number of pixels of the concave image between the ridges that maintain continuity increases, but the number of pixels of the image of the sweat gland near the isolated point decreases conversely.

Next, the labeling image having the number of pixels equal to or larger than a predetermined value is erased (step 1-8). That is, if the number of pixels is less than a predetermined value, it is considered as a sweat gland, and conversely, if the labeling image with a number of pixels is more than a predetermined value, it is considered as a ridge of a fingerprint ridge, and only the sweat gland is left, and the ridge of a ridge is erased. To do.

Next, the number of sweat glands in the predetermined area A of the fingerprint is counted (step 1-9) and compared with the number of sweat glands in the predetermined area of the person who is registered in advance, and it is determined whether the difference is within the allowable range. Judge (step 1-10). If it is within the allowable range, the person is identified (step 1-11). However, if it is not within the allowable range, it is determined that the person is not the person (step 1-12).

[0012]

As described above, according to the method for identifying an individual by the sweat glands of the finger according to the present invention, a fingerprint image is input and binarized,
The binarized image is thinned and labeled to count the number of pixels in each group in the labeling image, and the groups having a predetermined number of pixels or more are erased as recesses between the fingerprint ridges, and the above-described areas in the predetermined area of the fingerprint are deleted. The group left after erasing the recesses is made a sweat gland, and the number is compared with the number registered in advance to identify the individual, so it is possible to identify the individual in a quick and easy method based on the sweat gland image conventionally treated as image noise. Has the effect.

[Brief description of drawings]

FIG. 1 is a flowchart showing an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a binary image.

FIG. 3 is a conceptual diagram of a thinned image.

FIG. 4 is a block diagram of an apparatus for implementing the present invention.

[Explanation of symbols]

 CPU central processing unit IPU image processing unit IM image memory SL system bus LS local bus A predetermined area

Claims (1)

[Claims] 1. A fingerprint image is input, the input image is binarized, the binarized image is thinned, the thinned image is labeled, and the number of pixels of each group in the labeled image is counted. A finger characterized by erasing a group having a predetermined number of pixels or more and comparing the number of groups remaining after the group erasing in a predetermined area of the fingerprint with the number registered in advance to identify the input person Individual identification method based on sweat glands.