CN218004132U - Handprint collecting system - Google Patents

Abstract

The utility model provides a hand print collection system. The handprint collection system includes: a lighting system comprising one or more blue light sources and one or more green light sources, each light source for emitting light towards a handprint acquisition area for placement of part or all of a user's hand; one or more image acquisition devices for acquiring an image of the handprint acquisition area while the illumination system is emitting light to the handprint acquisition area to obtain a handprint image; and the processing device is used for processing the hand print images acquired by the one or more image acquisition devices. The applicability of the handprint collecting system to different skin states can be enlarged, and therefore the collecting requirements of various crowds are favorably met.

Description

Handprint collecting system

Technical Field

The utility model relates to a handprint gathers technical field, specifically relates to a handprint collection system.

Background

Handprint recognition technology is one of many biometric identification technologies (biometrics). The biometric technology is a technology for identifying an individual by using physiological characteristics or behavioral characteristics inherent to a human body. Due to the advantages of convenience, safety and the like of biological characteristic identification, the biological characteristic identification technology has wide application prospect in the fields of identity authentication identification, network safety and the like. Among the biometric techniques that may be used are handprints (e.g., fingerprints), human faces, voice prints, irises, etc., which are the most widely used.

The handprint recognition technology firstly needs to collect the handprint. In the existing hand print acquisition technology, the consideration for different crowds is not good enough. For example, the collection effect of the handprint under various different conditions, such as over-dry, over-wet, shallow handprint, etc., is limited, and it is difficult to meet the collection requirements of various crowds.

SUMMERY OF THE UTILITY MODEL

To at least partially solve the problems in the prior art, a handprint acquisition system is provided.

According to the utility model discloses an aspect provides a handprint collection system, include: a lighting system comprising one or more blue light sources and one or more green light sources, each light source for emitting light towards a handprint acquisition area for placement of part or all of a user's hand; one or more image acquisition devices for acquiring an image of the handprint acquisition area while the illumination system is emitting light to the handprint acquisition area to obtain a handprint image; and the processing device is used for processing the hand print images acquired by the one or more image acquisition devices.

According to the utility model discloses handprint collection system adopts blue light source and green light source to be image acquisition device light filling together when gathering the handprint image. The applicability of the handprint collecting system to different skin states can be expanded, and therefore the collecting requirements of various crowds are favorably met.

A series of concepts in a simplified form are introduced in the disclosure, which will be described in further detail in the detailed description section. The summary of the invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

The advantages and features of the present invention are described in detail below with reference to the accompanying drawings.

Drawings

The following drawings of the present invention are used herein as part of the present invention for understanding the present invention. There are shown in the drawings, embodiments and descriptions thereof, which are used to explain the principles of the invention. In the drawings, there is shown in the drawings,

fig. 1 shows a schematic diagram of a handprint acquisition system and associated finger and handprint acquisition regions according to an embodiment of the present invention;

fig. 2 shows a schematic diagram of a handprint acquisition system and associated finger and handprint acquisition regions according to an embodiment of the present invention;

fig. 3 shows a schematic view of a portion of a handprint acquisition system according to an embodiment of the present invention;

fig. 4 shows a schematic diagram of a partial structure of a handprint acquisition system and associated finger and handprint acquisition zones according to an embodiment of the present invention.

Detailed Description

In the following description, numerous details are provided to provide a thorough understanding of the present invention. One skilled in the art, however, will understand that the following description illustrates only a preferred embodiment of the invention and that the invention may be practiced without one or more of these details. In addition, some technical features that are well known in the art are not described in detail in order to avoid obscuring the present invention.

In order to solve the technical problem at least partially, the embodiment of the utility model provides a handprint collection system. When the image acquisition device acquires the hand print image, the system can adopt the blue light source and the green light source to supplement light (or illuminate) for the image acquisition device. The handprint collection system has the advantages and disadvantages of the handprint collection system under different skin states through blue light supplement and green light supplement, and meanwhile, the applicability of the handprint collection system to different skin states can be enlarged through the two light sources for light supplement, so that the collection requirements of various crowds are favorably met. Although the fingerprint is mainly described herein when describing the hand print collecting system according to the embodiment of the present invention, it is understood that the hand print collecting system according to the embodiment of the present invention may be used for collecting other similar hand prints such as palm prints, besides the finger prints.

According to the utility model discloses an aspect provides a hand line collection system. Fig. 1 shows a schematic diagram of a handprint acquisition system 100 and associated finger 200 and handprint acquisition area 300 according to an embodiment of the present invention. The handprints described herein may include, but are not limited to, fingerprints of fingers and/or palmprints of palms, etc. Fig. 1 illustrates the structure and the working principle of a fingerprint collecting system according to an embodiment of the present invention by taking fingerprint collection of a finger as an example.

As shown in FIG. 1, handprint acquisition system 100 may include one or more image acquisition devices, illumination systems, and processing devices 130. The illumination system comprises one or more blue light sources and one or more green light sources, each for emitting light towards the handprint acquisition area 300. The blue light sources included in the lighting system form a blue light source group, and the green light sources included in the lighting system form a green light source group. Handprint acquisition area 300 is used to place part or all of a user's hand, such as finger 200. One or more image capture devices are used to capture images of handprint capture area 300 while the illumination system is emitting light to handprint capture area 300 to obtain a handprint image. The processing device 130 is configured to process the handprint images acquired by the one or more image acquisition devices. It is noted that the light sources comprised by the lighting system described herein may be any type of light source not used for encoding, including but not limited to one or more of the following: point light sources, line light sources, area light sources, etc. The point light source may be, for example, a light strip composed of a plurality of point light sources. Illustratively, at least part of the light sources and the one or more image acquisition devices in the illumination system are located on the same side of the handprint acquisition area, e.g. below the handprint acquisition area. The light source on the same side of the handprint acquisition area as the one or more image acquisition devices may be referred to as the primary light source. For example and without limitation, the lighting system may include, in addition to the primary light source, a secondary light source located near the handprint capture area to illuminate the handprint from a location closer to the handprint. The secondary light source is closer to the center of the handprint acquisition region than the primary light source. For example, the primary light source may be disposed below the handprint acquisition region, while the center of gravity of the secondary light source (which may be understood as the respective center of gravity of each of the secondary light sources) may be located at or substantially at the same level as the center of the handprint acquisition region. At least some of the auxiliary light sources may be located at predetermined positions on both sides of the handprint acquisition region (a first side of the two sides corresponds to the first predetermined position and a second side corresponds to the second predetermined position), and/or at least some of the light sources may be located at predetermined positions near the fingertip position (which may be referred to as third predetermined positions). Light sources located at predetermined positions on either side of the handprint acquisition region may emit light toward that side of the handprint acquisition region. A light source located near the fingertip position may emit light towards the fingertip position. The fingertip position refers to a position where the user's fingertip is expected to fall when the user places a finger or palm on the hand print capturing area. It will be appreciated that the position of the auxiliary light source is set to target the illumination of the hand without affecting the imaging of the image acquisition system (e.g., the auxiliary light source does not enter the imaging range of the image acquisition device). The auxiliary light source may also comprise one or more blue light sources and one or more green light sources.

For example, the handprint collecting system of the embodiment of the present application may be non-contact, that is, the handprint collecting area is a space, and a user may collect a part or all of the hand by placing the hand in the handprint collecting area, and there is no entity in contact with the handprint. Of course, alternatively, the handprint collecting system may also be a contact type, for example, a handprint collecting system that runs on a smart device and collects handprints by contacting a finger with a screen.

Fig. 1 shows three image acquisition devices 112, 114 and 116. Furthermore, fig. 1 also shows a lighting system comprising at least one blue light source and at least one green light source.

By way of example and not limitation, the illumination system shown in fig. 1 may include three light source sets in one-to-one correspondence with three image capturing devices, each light source set including at least one blue light source and at least one green light source for illuminating when its corresponding image capturing device performs image capturing.

For example, the light source set may be further divided into light source subsets according to different relative position relationships between the light sources in the light source set and the image capturing devices corresponding to the light source set. For example, the light sources in the light source set are distributed on two sides of the image acquisition device, the left light source serves as a light source subset, and the right light source serves as a light source subset. For example, in FIG. 1, a first set of light sources includes subsets of light sources 122 and 122', a second set of light sources includes subsets of light sources 124 and 124', and a third set of light sources includes subsets of light sources 126 and 126'.

It should be noted that the structure of the handprint collecting system 100 shown in fig. 1 is only an example and is not a limitation of the present invention, and the handprint collecting system 100 according to the embodiment of the present invention is not limited to the situation shown in fig. 1. For example, the number of image acquisition devices may be more or less than three. In addition, the number of light source subsets included in the light source set around each image capturing device shown in fig. 1 and the positions of the light source subsets may also be changed as needed. For example, any set of light sources may also include a single subset of light sources (e.g., the first set of light sources may include only subset of light sources 122) or more than two subsets of light sources.

Illustratively, the lighting system comprises at least one light source pair, each light source pair comprising one blue light source and one green light source. This example is a preferred arrangement of light sources to facilitate each pairing of a blue light source and a green light source as close as possible, so that the acquisition conditions for the blue and green channels of the image are as close as possible to unity, which helps to improve the accuracy of subsequent handprint images obtained based on both channels.

For example, in an embodiment where the illumination system comprises one or more sets of light sources in a one-to-one correspondence with one or more image capture devices, each set of light sources may comprise at least one pair of light sources, each pair of light sources comprising one blue light source and one green light source. Therefore, when each image acquisition device acquires an image, the imaging conditions of the blue channel and the green channel corresponding to the image acquisition device are as close as possible to be consistent. For example, any subset of light sources in FIG. 1 may include one light source pair.

The illumination system comprises at least one blue light source and at least one green light source, on the basis of which the number of light sources in the illumination system can be set to any suitable number as desired. The light sources comprised in the illumination system may be divided into a group of blue light sources and a group of green light sources, if classified by color. The number of blue light sources included in the blue light source group and the number of green light sources included in the green light source group may be arbitrary, and may be the same or different. Preferably, the number of blue light sources included in the blue light source group coincides with the number of green light sources included in the green light source group.

Illustratively, the handprint capturing system 100 may further include a housing, and at least a portion of the light sources in the one or more image capturing devices and the lighting system may be disposed inside the housing. Illustratively, a window may be disposed on the housing, and a light-transmitting plate may be disposed on the window. The handprint collection area can be located above the light-transmitting plate, a user places a finger in the handprint collection area, and the illumination system below can irradiate light on the finger through the light-transmitting plate. The image acquisition device below the fingerprint acquisition area can also acquire the fingerprint image of the finger through the light-transmitting plate. Of course, the embodiment in which the handprint capturing area is located above the light-transmitting plate is merely an example, the light-transmitting plate is optional, and the position of the handprint capturing area relative to at least some of the light sources in the image capturing device and the illumination system may also be changed as long as the handprint capturing area is located within the imaging range of the image capturing device and within the illumination range of the illumination system. In the description herein, the imaging range of any image capturing device refers to the range covered by a cone with the lens optical center of the image capturing device as the vertex and the angle of view of the image capturing device as the cone angle. It should be noted that the light-transmitting plate can be installed in the housing to set the height so as to prevent the virtual image formed by the illumination light source passing through the light-transmitting plate from entering the imaging range of the image acquisition device. It will be appreciated that the lighting system may also include a light source located adjacent the handprint collection area, that is, the lighting system may also include a secondary light source located above the light-transmitting panel to illuminate the hand at a closer distance from the hand. The auxiliary light source may likewise comprise both a blue light source and a green light source. The auxiliary light source may include one or more of a point light source, a line light source, and a surface light source, and may be located near the hand in the handprint collecting area, for example, the auxiliary light source includes a lamp strip composed of point light sources on both sides of the handprint collecting area, and a point light source near the fingertip position.

The handprint acquisition area may be an area of physical space having any suitable shape, such as a spherical area, a cubical area, or any other regular or irregular area, etc. By way of example and not limitation, the imaging range of one or more image capture devices may cover the entire handprint capture area, facilitating the capture of images of the entire handprint capture area. After the user places the finger or palm on the hand print acquisition area, the image acquisition device can acquire the fingerprint or palm print image of the user. The hand texture acquisition system may be used to acquire only one type of hand texture or may be used to acquire multiple types of hand textures. For example, the hand print collecting system can be used for collecting fingerprints of a fingertip area only (including fingerprints on the front side and the side of a finger pad), can also be used for collecting fingerprints of the fingertip area and palm prints, and can also be used for collecting fingerprints of the fingertip area, and lines on other finger joints except the finger joint where the fingertip is located and palm prints of the palm. Multiple types of hand textures may share the same handprint acquisition area, or different handprint acquisition areas may be used, with the handprint acquisition areas of different types of hand textures partially or fully overlapping.

The number of image capturing devices included in handprint capturing system 100 may be set to any suitable number as desired. For example, the number of image capture devices may be 1, 2, 3, or 6, and so on.

In one embodiment, handprint acquisition system 100 may include a single image acquisition device. In this case, optionally, a hand print image at a single angle may be acquired by the image acquisition device. Of course, alternatively, in this case, hand print images at a plurality of angles may also be acquired by rotating and/or moving the image acquisition device. When the collected handprint is a fingerprint, the implementation scheme of collecting the handprint image under a single angle is more suitable for simulating the fingerprint image obtained by plane printing.

In another embodiment, handprint acquisition system 100 may include a plurality of image acquisition devices. In this case, the handprint images at a plurality of angles may be optionally acquired by a plurality of image acquisition devices. That is, the optical axes of any two image capturing devices of the plurality of image capturing devices may be at a preset angle with respect to each other, which is not equal to 0, so as to capture handprint images at different angles. When the fingerprint of gathering, can be with a plurality of image acquisition device's angle/height adjustment for not only can gathering the positive fingerprint image of finger tripe, still can gather finger tripe side fingerprint image, the fingerprint image that obtains is pressed down to the realization scheme of gathering the fingerprint image under the multi-angle is more fit for simulating the fingerprint image that obtains through rolling. It will be appreciated that a plurality of image capture devices may be arranged such that their optical axes are substantially perpendicular to the region of the handprint they are to capture. For example, the optical axis of the image capturing device for capturing the fingerprint image of the finger pad front face is perpendicular to the finger pad front face area, and the optical axis of the image capturing device for capturing the fingerprint image of the finger pad side face is perpendicular to the finger pad side face area. When the handprint acquisition system is used for acquiring multiple types of hand textures, the multiple image acquisition devices may include an image acquisition device for acquiring a first type of hand texture and an image acquisition device for acquiring a second type of hand texture, and the field of view, the focal length, the placement angle and the position of the image acquisition device for acquiring the first type of hand texture and the image acquisition device for acquiring the second type of hand texture may be different. It will be appreciated that the image capture device used to capture the palm prints has a larger field of view than the image capture device used to capture the fingerprints. The field of view of an image capture device used to capture a fingerprint or a palm print may refer to the field of view of a single image capture device or to the field of view of a combination of multiple image capture devices. For the same image acquisition device, it can be used to acquire both the first type of hand texture and the second type of hand texture.

It will be appreciated that the image capture device may also include a preview image capture device dedicated for preview purposes, which may have a larger field of view than the image capture device used for capture, for example a single preview image capture device field of view covering the entire palm print and a common field of view for multiple image capture devices used for capture covering the entire palm print. The plurality of image capture devices may capture a plurality of handprint images of a target site, such as a user's finger or palm, in a one-to-one correspondence, and the plurality of handprint images may correspond to different portions of the target site. For example, the number of image capturing devices is 3, the hand print image captured by the first image capturing device may correspond mainly to the left portion of the finger or palm (i.e., the side area, specifically, the left side area), the hand print image captured by the second image capturing device may correspond mainly to the middle portion of the finger or palm (i.e., the front area), and the hand print image captured by the third image capturing device may correspond mainly to the right portion of the finger or palm (i.e., the side area, specifically, the right side area).

The optical axis of the image capturing device is oriented toward a side of the target area where the hand print is located, such as the palm of the palm or the palm of the finger. For example, if the finger pad of the finger is oriented toward the ground plane when the user is capturing the hand print, the optical axis of the image capturing device may be disposed vertically upward or obliquely upward so as to capture the fingerprint of the finger of the user.

In the case where the number of the image pickup devices is plural, the heights at which the centers of gravity of the plural image pickup devices are located may be set to be uniform or non-uniform. For example, in the case of acquiring a palm print, the heights at which the centers of gravity of the plurality of image acquisition devices are located may be uniform. In the case of the acquisition of hand prints, the centers of gravity of the plurality of image acquisition devices may lie on an arc of a circle.

The processing device 130 is communicatively coupled to one or more image capture devices, which may be wired or wireless. The processing device 130 may receive the handprint images acquired by the one or more image acquisition devices, and process the handprint images. Processing device 130 may perform any desired processing operations on the fingerprint image, including but not limited to one or more of the following: acquiring depth information from the hand print image; and carrying out splicing processing and the like on the hand print images acquired by the plurality of image acquisition devices.

By way of example and not limitation, the processing device 130 may also be communicatively connected with the lighting system, which may be a wired or wireless connection. In this case, the processing device 130 may control the light sources in the lighting system to emit light according to the various light emission schemes described herein. Of course, alternatively, the light emission of each light source in the lighting system may also be controlled by other control devices different from the processing device 130. The control device can be a control device in the handprint acquisition system, and can also be an external control device independent of the handprint acquisition system.

The reflection, absorption, and transmittance of light are different for different persons, and the reflection, absorption, and transmittance of light of different wavelengths are different for the same person's hand (hereinafter, the finger or palm is taken as an example). In addition, the reflection, absorption and transmission of light in the dry, wet or sweat state of the fingers or palms of the same person are different.

The inventor finds that: when the hand print image is collected, if only green light is used for supplementing light, because the green light is absorbed by the fingers or the palm strongly, on one hand, the light reflected by the fingers or the palm to the image collecting device is weakened, so that the contrast of the image is reduced, and on the other hand, the fingers or the palm can generate fluorescence and phosphorescence by absorbing the light, so that the collected image becomes fuzzy; and if only blue light is used for supplementing light, because the blue light is absorbed weakly by fingers or palms, light reflected by the fingers or palms to the image acquisition device is strong, and the image acquisition device is easy to overexpose to people with shallow skin, and if the hands are too dry and have dead skin or sweat and other liquid, the reflection is strong, so that the contrast ratio is easy to deteriorate. However, blue and green light each have their own advantages. For example, the contrast of ridges and valleys of fingerprints or palm prints under the condition of blue light supplement is improved, and the method is suitable for people with shallow fingerprints; and the finger which is too dry or too wet is shot more clearly under the condition of green light supplement.

Therefore, the inventor selects to supplement light with light sources of two colors of blue and green at the same time, so that the two lights can complement each other, and a high-quality handprint image can be obtained relatively easily after processing as long as a clear image can be acquired under the light of one color. Therefore, the scheme of light supplement through blue and green light sources when acquiring the hand print can expand the applicability of the hand print acquisition system to different skin states, thereby being beneficial to taking into account the acquisition demands of various crowds.

In order to avoid the mutual influence of blue and green lights, the wavelength distinction degree of the blue and green light sources can be set as large as possible, namely, the blue light source with shorter wavelength (more purple) and the green light source with longer wavelength (more yellow) can be selected as much as possible. By way of example and not limitation, blue light as described herein may be light having a wavelength of less than 430nm, such as 405nm, and green light may be light having a wavelength of greater than 540nm, such as 560 nm.

In a particular embodiment, the illumination system may comprise one or more sets of light sources, each set of light sources comprising at least one blue light source and at least one green light source, the one or more sets of light sources being in one-to-one correspondence with the one or more image capturing devices.

In this embodiment, the light source set corresponding to any image capturing device is responsible for supplementing light to the image capturing device, and each time the image capturing device captures an image, only the light source set corresponding to the image capturing device may emit light, and the other light source sets do not emit light. And each image acquisition device is distributed with a corresponding light supplement light source, so that the control and management of the image acquisition devices and the light sources are conveniently realized, and the mutual interference of different light sources during image acquisition is conveniently avoided.

For example, but not by way of limitation, for any of the one or more sets of light sources, the direction in which the light source of the set of light sources emits light may be substantially perpendicular to the area of the handprint captured when the light source of the set of light sources is in the on state. In this way, the light ray is approximately perpendicular to the handprint region, which is beneficial to ensuring that the valley and ridge conditions of the handprint can be presented more accurately in the handprint image. When a plurality of image capturing devices may be arranged such that the optical axes thereof are substantially perpendicular to the handprint regions to be captured, the direction in which the light source in each light source set emits light is substantially parallel to the direction of the optical axis of the corresponding capturing device, which may be achieved by arranging the light sources in the light source sets sufficiently close to their corresponding image capturing devices.

With continued reference to FIG. 1, optical axes 1122, 1142, and 1162 of image capture devices 112, 114, and 116, respectively, are shown. As can be seen from fig. 1, the light emitted by the light sources in each light source set is parallel to the optical axis of the corresponding collecting device. It should be noted that the parallelism described herein does not necessarily require that the parallel objects be perfectly parallel to each other, but may be substantially parallel. For example, the parallel may mean that an included angle between parallel objects (in this embodiment, the direction of the light emitted by the light source and the optical axis direction of the corresponding image capturing device or any two light emitted by the same parallel light source) is smaller than a preset threshold. The threshold value may be set as small as possible, for example, 10 °.

According to the utility model discloses, lighting system includes that at least one light source is to, every light source is to including a blue light source and a green light source, and the distance between the blue light source and the green light source that same light source is internal is less than preset distance threshold value.

When image acquisition is carried out, the blue light source and the green light source in the same light source pair can be simultaneously turned on or turned off, so that the imaging conditions of the blue channel and the green channel are more favorably ensured to be close to the same. The consistent imaging conditions of the blue channel and the green channel are beneficial to improving the fusion effect of the blue channel image and the green channel image during the fusion of subsequent images.

Such embodiments are merely examples and are not intended to limit the present invention, and light sources in a lighting system may both be unpaired or the lighting system may include both light source pairs and unpaired light sources.

Each set of light sources may include at least one pair of light sources. Each light source pair may include a blue light source and a green light source. The blue and green light sources in each light source pair may be as close together as possible to further ensure that the imaging conditions for the blue and green channels approach unity. For example, referring back to FIG. 1, any subset of light sources shown therein (e.g., 122', 124', 126 ') may include at least one light source pair, such that the blue and green light sources in the subset of light sources are conveniently located closer together.

The preset distance threshold may be set to any suitable value as desired, and the present invention is not limited thereto.

According to the embodiment of the utility model provides a lighting system is located one or more this image acquisition device's imaging range outside. In embodiments where the illumination system includes one or more sets of light sources, the set of light sources corresponding to any one image capture device may be located outside the imaging range of that image capture device.

The light source can be arranged at any suitable position around the image acquisition device as long as the imaging of the image acquisition device is not obstructed. The light source set corresponding to any image acquisition device is arranged outside the imaging range of the image acquisition device, so that the light source can be effectively prevented from obstructing the image acquisition device to acquire the handprint image.

According to the utility model discloses, one or more image acquisition device include first image acquisition device, second image acquisition device and third image acquisition device, and wherein, the optical axis of first image acquisition device is perpendicular with the plane of one or more image acquisition device of orientation in hand line collection area, and the optical axis of second image acquisition device and first image acquisition device's optical axis become the first contained angle of predetermineeing, and the optical axis of third image acquisition device and first image acquisition device's optical axis become the second and predetermine the contained angle.

The plane of the handprint acquisition area facing the one or more image acquisition devices may be, for example, a plane parallel to the plane of the light shield. In the case where the palm of the palm or the palm of the finger is required to face the ground plane when the user is specified to acquire the hand print, the plane of the hand print acquisition area facing the one or more image acquisition devices may be parallel to the ground plane. At this time, the optical axis of the first image pickup device may be directed vertically upward, and the optical axes of the second image pickup device and the third image pickup device may be directed obliquely upward.

Any one of the first preset included angle and the second preset included angle can be set to any suitable value according to the requirement, and the utility model discloses do not limit this. The first predetermined angle and the second predetermined angle may be the same or different. Illustratively, the first predetermined angle may be in a range of 0 to 45 degrees, and the second predetermined angle may be in a range of 0 to 45 degrees.

According to the utility model discloses, first image acquisition device, second image acquisition device and third image acquisition device's optical axis is located the coplanar.

The three image acquisition devices are simple in arrangement in a mode that the optical axes of the three image acquisition devices are positioned in the same plane and are arranged in a non-parallel mode, and the images of a plurality of different parts of target parts such as fingers or palms are acquired conveniently.

According to the utility model discloses, hand line collection system can also include: the structured light projector is used for emitting structured light to the handprint collecting area; the processing device can process the hand print images acquired by one or more image acquisition devices in the following way: and respectively extracting gray level images of channels corresponding to the structured light from the handprint images acquired by one or more image acquisition devices, and determining handprint depth information based on the extracted structured light images.

It will be appreciated that the structured light projector emits structured light for encoding as compared to an illumination source that is not used for encoding, but only for illumination.

Fig. 2 shows a schematic diagram of a handprint acquisition system 100 and associated finger 200 and handprint acquisition area 300, according to an embodiment of the present invention. Fig. 2 shows that the handprint acquisition system 100 further comprises a structured light projector 140. Fig. 1 may be understood as a front view of handprint acquisition system 100, while fig. 2 may be understood as a left side view of handprint acquisition system 100. It is noted that fig. 2 illustrates only a single image capture device 114 as an example for the description, and those skilled in the art will understand the location of other image capture devices in fig. 2.

The structure of the handprint collecting system 100 shown in fig. 2 is only an example and is not a limitation of the present invention, and the handprint collecting system 100 according to the embodiment of the present invention is not limited to the situation shown in fig. 2. For example, FIG. 2 shows that the structured light projector 140 is located closer to the base of the finger, when the head (where the light is emitted) is farther from the base of the finger than the tail (where the light is emitted) of the structured light projector 140, where the particular cross-section 302 is the cross-section of the finger 200 that overlaps the central axis of the fingerprint collection area 300, bounded by the particular cross-section 302. The above arrangement of the structured light projector 140 is merely an example and it may also be located on the side further from the finger root bounded by the particular cross-section 302, i.e. the head of the structured light projector 140 may also be located closer to the horizontal distance of the finger root than the tail. In fact, the structured light projector 140 can be disposed at any suitable location as desired, as long as it does not interfere with the imaging of the image capture device and can illuminate the handprint capture area.

By way of example and not limitation, the height at which the center of gravity of the structured light projector 140 is located may be set to substantially coincide with the height at which the combined center of gravity or the lowest center of gravity of the one or more image capture devices is located. Therefore, the components in the handprint acquisition system can be arranged more compactly, and the volume of the equipment is reduced. By way of example and not limitation, the center of gravity of the structured light projector 140 may be at a lower elevation than the combined or lowest center of gravity of the one or more image capture devices, thereby ensuring that the light projection area of the structured light projector 140 is large enough to cover the capture area corresponding to the target site as effectively as possible.

In the case of a fingerprint, where the target area is small, the height of the center of gravity of the structured light projector 140 may be set to substantially coincide with the height of the combined center of gravity or the lowest center of gravity of the one or more image capture devices. In the case of a large target area for palm print acquisition, the center of gravity of the structured light projector 140 may be at a lower elevation than the combined or lowest center of gravity of the one or more image acquisition devices.

And extracting a gray level image of a channel corresponding to the structured light from any handprint image, wherein the gray level image is the structured light image corresponding to the handprint image. It can be understood that the structured light image includes depth information corresponding to each pixel in the original handprint image. Therefore, the structured light projector can further acquire the hand-print depth information of the target portion such as the finger or the palm. And acquiring the handprint depth information, and facilitating the subsequent simulated printing handprint image. At present, a plurality of occasions may need to be applied to fingerprint images acquired by a pressing and printing mode, so that the scheme of adding structured light can correctly expand the acquired handprint images into two-dimensional images, and the two-dimensional images are compatible with the handprint images acquired by the pressing and printing mode in the subsequent comparison process, and the application scene of a handprint acquisition system is expanded.

For example, but not by way of limitation, since the fill light uses two colors of blue and green, in order to reduce interference to the blue and green channel, the structured light may be selected as much as possible from the color of blue and green, such as red. Illustratively, the structured light emitted by the structured light projector may be red light of 660nm wavelength. The illumination light and the structured light are respectively selected from blue, green and red, so that images of different channels can be conveniently extracted subsequently. Of course, the structured light need not be red light, and the effect of the structured light in the cyan channel can be removed by image processing.

According to the utility model discloses, the direction of structured light projector emission light and the plane at one or more image acquisition device's optical axis place become the third preset angle.

The third preset angle can be set to any suitable value as required, and the present invention is not limited thereto. The third preset angle may be different from the first preset angle and the second preset angle, or may be the same as the first preset angle and/or the second preset angle.

It is assumed that the optical axes of all image capturing devices in fig. 2 are in the same plane and that this plane appears as a straight line parallel to the optical axis 1142 in the left view shown in fig. 2. It can be seen from fig. 2 that the direction of the light rays emitted by the structured light projector 140 is at an angle to the plane of the optical axis of the image capture device. The mode of arranging the structured light projector on the side surface of the image acquisition device is convenient for enabling the structured light projector to avoid the imaging range of the image acquisition device so as to avoid obstructing the imaging of the image acquisition device. In addition, the mode of arranging the structured light projector on the side face of the image acquisition device also facilitates the arrangement of the structured light projector at a height close to that of the image acquisition device, which is favorable for realizing more compact layout in the handprint acquisition system.

According to the utility model discloses, hand line collection system 100 can also include the casing, and one or more image acquisition device and lighting system set up in the casing, and the position department that faces hand line collection area on the casing is provided with the window, is provided with the light-passing board on the window.

The above describes an embodiment in which the image capturing device and the illumination system are disposed in the housing, and the light-transmitting plate is disposed on the housing, and the description is omitted here. The light-transmitting plate may be implemented using any suitable material, including but not limited to glass, etc. Illustratively, the glass may be an antireflection coated glass. The light-transmitting plate can play waterproof dirt-proof effect, helps to protect the major structure in the handprint collection system, and prolongs the service life of equipment.

According to the embodiment of the present invention, the handprint collecting system 100 may further include a limiting component, the limiting component defines a handprint collecting area, and the proximal end of the limiting component is provided with an inlet to allow part or all of the hand of the user to pass through the inlet and extend into the handprint collecting area; the far end of the limiting component is provided with a stopping part, and the stopping part is located at a preset position of the hand pattern collecting area along the extending direction so as to limit the position of the hand of the user partially or completely extending into the hand pattern collecting area.

The proximal end of the stop member may be understood as the end of the stop member that is closer to the front of the user when the user is using the handprint acquisition system normally, and the distal end of the stop member may be understood as the end of the stop member that is farther from the front of the user when the user is using the handprint acquisition system normally.

Fig. 3 shows a schematic diagram of a portion of a handprint acquisition system according to an embodiment of the present invention. In fig. 3, the spacing member 150 is shown, with the entrance 152 and the stop 154 of the spacing member 150 shown. The area between the entrance 152 to the stopper 154 of the restricting member 150 may be set as a hand-thread collecting area 300. A target portion such as a user's finger or palm may extend into the fingerprint acquisition area 300 through the entrance 152. The stopping portion 154 can limit the limit position that the target portion such as the finger or the palm of the user can reach, and prevent the user from extending the target portion such as the finger or the palm too far. By means of the position limiting component 150, the user can be conveniently guided to place the target part such as the finger or the palm at the right position, so as to ensure that the part (such as the first knuckle of the finger closest to the fingertip) on the target part which is more suitable for detection can fall into the handprint collecting area.

According to the utility model discloses, handprint collection system 100 can also include shading parts, and shading parts and lighting system are middle and at least partial light source is located the relative both sides in handprint collection area respectively.

Referring to FIG. 3, a shading member 160 is shown, which is located on opposite sides of the handprint collecting area 300 from at least some of the light sources in the lighting system. The shading part is positioned above the handprint collecting area, and at least part of light sources in the lighting system are positioned below the handprint collecting area. Through the light shielding component 160, the light emitted by the light source can be prevented from affecting the user experience to the outside, and meanwhile, the stray light from the outside can be prevented from irradiating the inside of the handprint collecting area and further interfering the collection of the handprint.

In case the handprint acquisition system comprises a light shield and a light transmissive plate, the handprint acquisition area may be at least a part of an area located between the light shield and the light transmissive plate.

Fig. 4 shows a schematic diagram of a partial structure of the handprint acquisition system 100 and associated finger and handprint acquisition regions according to an embodiment of the present invention. Note that fig. 4 is a schematic diagram, and does not show the actual shape or size of each component. Referring to FIG. 4, the light blocking member 160 and the light transmissive panel 170 are shown with the fingerprint acquisition area 300 disposed therebetween. In addition, fig. 4 also shows two sets of auxiliary light sources 1281 and 1282 on both sides of the handprint capturing area 300 and an auxiliary light source 1283 near the fingertip position of the handprint capturing area 300. In the example shown in fig. 4, two sets of auxiliary light sources 1281 and 1282 at both sides of the handprint collecting area 300 are each a light strip, and the auxiliary light source 1283 near the fingertip position of the handprint collecting area 300 is a point light source, but this is merely an example, and the auxiliary light source may have other implementation forms. Note that, in fig. 4, the finger 200 is indicated by a dotted line for the sake of convenience of distinction.

According to the embodiment of the present invention, in the case that the handprint collecting system further includes the above-mentioned position limiting component 150, the handprint collecting system may further include a light shielding component 160, and the light shielding component 160 and the lighting system are respectively located at two opposite sides of the handprint collecting area; the position limiting member 150 further includes a connecting portion connecting the inlet and the stopper portion, and an upper surface of the connecting portion is attached to a lower surface of the light shielding portion.

Referring to fig. 3, a connecting portion 156 in the spacing member 150 is shown connecting the entrance 152 and the stop 154. The upper surface of the connecting portion 156 may be attached to the lower surface of the light shielding portion 160, which may better prevent light emitted from the light source from being dissipated to the outside and better prevent stray light from the outside from being irradiated to the handprint collecting area.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", and the like are used in an orientation or positional relationship indicated based on normal use, merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element so indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. The term "connected" may mean directly connected or indirectly connected through other devices or elements.

The above description is only for the specific embodiments of the present invention or the description of the specific embodiments, the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. A handprint acquisition system, comprising:

a lighting system comprising one or more blue light sources and one or more green light sources, each light source for emitting light towards a handprint acquisition area for placement of part or all of a user's hand;

one or more image capture devices for capturing images of the handprint capture area while the illumination system is emitting light to the handprint capture area to obtain a handprint image;

and the processing device is used for processing the hand print images acquired by the one or more image acquisition devices.

2. The system of claim 1, wherein the blue light source emits blue light having a wavelength less than 430nm and the green light source emits green light having a wavelength greater than 540nm.

3. The system of claim 1 or 2, wherein the handprint acquisition system further comprises:

a structured light projector for emitting structured light towards the handprint collection area;

the processing device processes the hand print images acquired by the one or more image acquisition devices in the following way:

and respectively extracting gray level images of channels corresponding to the structured light from the handprint images acquired by the one or more image acquisition devices, and determining handprint depth information based on the extracted structured light images.

4. The system of claim 1 or 2, wherein the one or more image acquisition devices comprise a first image acquisition device, a second image acquisition device, and a third image acquisition device, wherein,

the optical axis of the first image acquisition device is perpendicular to the plane of the one or more image acquisition devices towards the handprint acquisition area, the optical axis of the second image acquisition device is at a first preset included angle with the optical axis of the first image acquisition device, and the optical axis of the third image acquisition device is at a second preset included angle with the optical axis of the first image acquisition device.

5. The system of claim 4, wherein optical axes of the first image capture device, the second image capture device, and the third image capture device lie in a same plane.

6. The system of claim 1 or 2, wherein the handprint collection system further comprises a light blocking component, wherein the light blocking component and at least a portion of the light sources in the illumination system are located on opposite sides of the handprint collection area.

7. The system of claim 1 or 2, wherein the handprint acquisition system further comprises a stop member, the stop member defining the handprint acquisition region,

the proximal end of the limiting component is provided with an inlet to allow part or all of the hand of the user to penetrate through the inlet to extend into the handprint collecting area;

the far end of the limiting component is provided with a stopping part, and the stopping part is located at a preset position of the handprint collecting area along the extending direction so as to limit the position of the hand of the user extending into the handprint collecting area partially or completely.

8. The system of claim 7, wherein the handprint collection system further comprises a light blocking component, wherein the light blocking component and at least some of the light sources in the illumination system are located on opposite sides of the handprint collection area,

the limiting component further comprises a connecting part which is connected with the inlet and the stopping part, and the upper surface of the connecting part is attached to the lower surface of the light shielding part.

9. The system of claim 1 or 2, wherein the illumination system comprises one or more sets of light sources, each set of light sources comprising at least one blue light source and at least one green light source, the one or more sets of light sources in one-to-one correspondence with the one or more image capture devices.

10. A system as claimed in claim 1 or 2, wherein the illumination system comprises at least one pair of light sources, each pair comprising a blue light source and a green light source, the distance between the blue light source and the green light source within the same pair being less than a preset distance threshold.

Images