CN116631015A - Fingerprint acquisition system and method - Google Patents

Abstract

The invention provides a fingerprint acquisition system and a fingerprint acquisition method. The hand print 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 palm print acquisition area for placing part or all of a user's hand; the one or more image acquisition devices are used for acquiring images of the palm print acquisition area while the lighting system emits light to the palm print acquisition area so as to obtain palm print images; and the processing device is used for processing the hand vein images acquired by the one or more image acquisition devices. The applicability of the palm print collecting system to different skin states can be enlarged, so that the collecting requirements of various crowds can be met.

Description

Fingerprint acquisition system and method

Technical Field

The invention relates to the technical field of palm print acquisition, in particular to a palm print acquisition system and a palm print acquisition method.

Background

The hand pattern recognition technique is one of many biometric techniques (biometrics). The biometric technology is a technology for identifying a person by using physiological or behavioral characteristics inherent to a human body. Due to the advantages of convenience, safety and the like of the biological feature recognition, the biological feature recognition technology has wide application prospect in the fields of identity authentication, network safety and the like. Available biometric techniques are hand prints (e.g., fingerprints, etc.), face, voiceprints, iris, etc., which are one of the most widely used.

The hand pattern recognition technology firstly needs to collect hand patterns. In the existing hand pattern acquisition technology, the compatibility of different people is not good enough. For example, the collection effect of the palm print under various different conditions such as overdry, shallow palm print and the like is limited, and the collection requirements of various crowds are difficult to achieve.

Disclosure of Invention

In order to at least partially solve the problems of the prior art, a hand print acquisition system and method are provided.

According to one aspect of the present invention, there is provided a palm print 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 palm print acquisition area for placing part or all of a user's hand; the one or more image acquisition devices are used for acquiring images of the palm print acquisition area while the lighting system emits light to the palm print acquisition area so as to obtain palm print images; and the processing device is used for processing the hand vein images acquired by the one or more image acquisition devices.

According to another aspect of the present invention, there is provided a method for collecting hand patterns implemented by using the above hand pattern collecting system, including: when the blue light source group emits light in a blue light emitting scheme and the green light source group emits light in a green light emitting scheme, acquiring images of the hand print acquisition area through one or more image acquisition devices to acquire hand print images acquired by the one or more image acquisition devices, wherein at least one hand print image is acquired under the condition that a blue light source with luminous intensity being not 0 exists in the blue light source group, and at least one hand print image is acquired under the condition that a green light source with luminous intensity being not 0 exists in the green light source group; the blue light source group comprises one or more blue light sources, the green light source group comprises one or more green light sources, the blue light emitting scheme is used for representing the light emitting intensity of each blue light source, and the green light emitting scheme is used for representing the light emitting intensity of each green light source; at the time of collection, the luminous intensity of at least one light source is not 0.

According to the system and the method for collecting the hand patterns, the blue light source and the green light source are adopted to supplement light for the image collecting device when the hand pattern images are collected. The applicability of the hand pattern acquisition system to different skin states can be enlarged, so that the acquisition requirements of various crowds can be met.

In the summary, a series of concepts in a simplified form are introduced, which will be further described in detail in the detailed description section. This summary 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.

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

Drawings

The following drawings are included to provide an understanding of the invention and are incorporated in and constitute a part of this specification. Embodiments of the present invention and their description are shown in the drawings to explain the principles of the invention. In the drawings of which there are shown,

FIG. 1 shows a schematic diagram of a palm print acquisition system and associated finger and palm print acquisition areas in accordance with one embodiment of the invention;

FIG. 2 shows a schematic diagram of a palm print acquisition system and associated finger and palm print acquisition areas in accordance with one embodiment of the invention;

FIG. 3 shows a schematic diagram of a portion of a palm print acquisition system according to one embodiment of the invention;

FIG. 4 shows a schematic diagram of a portion of the structure of a palm print acquisition system and associated finger and palm print acquisition areas in accordance with one embodiment of the invention; and

fig. 5 shows a schematic diagram of image acquisition and light source emission timing according to one embodiment of the invention.

Detailed Description

In the following description, numerous details are provided to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the following description illustrates preferred embodiments of the invention by way of example only and that the invention may be practiced without one or more of these details. Furthermore, some technical features that are known in the art have not been described in detail in order to avoid obscuring the invention.

In order to at least partially solve the above technical problems, an embodiment of the present invention provides a fingerprint collection system. When the image acquisition device acquires the hand image, the system can adopt the blue light source and the green light source to supplement light (or illumination) for the image acquisition device. The blue light supplementing and the green light supplementing have respective advantages and disadvantages for the collection of the hand patterns under different skin states, and meanwhile, the applicability of the hand pattern collection system to different skin states can be enlarged by adopting the two light source supplementing, so that the collection requirements of various crowds are met. Although the fingerprint is mainly described herein as an example when describing the fingerprint acquisition system or method according to the embodiment of the present invention, it will be understood that the fingerprint acquisition system according to the embodiment of the present invention may be used for acquiring other fingerprints, such as palms, other fingerprints, besides fingerprints of fingers.

According to one aspect of the present invention, a fingerprint acquisition system is provided. Fig. 1 shows a schematic diagram of a palm print acquisition system 100 and associated fingers 200 and palm print acquisition area 300 according to one embodiment of the invention. The fingerprints described herein may include, but are not limited to, fingerprints of fingers and/or palms, etc. Fig. 1 illustrates a fingerprint of a finger, which is taken as an example, to describe the structure of a fingerprint acquisition system and its operation principle according to an embodiment of the present invention.

As shown in fig. 1, the palm print acquisition system 100 may include one or more image acquisition devices, an illumination system, and a processing device 130. The illumination system includes one or more blue light sources and one or more green light sources, each for emitting light toward the palm print capture area 300. The blue light sources comprised by the illumination system constitute a blue light source group and the green light sources comprised by the illumination system constitute a green light source group. The palm print capture area 300 is used to rest part or all of a user's hand, such as the finger 200. The one or more image capture devices are configured to capture images of the palm print capture area 300 to obtain palm print images while the illumination system emits light to the palm print capture area 300. The processing device 130 is used for processing the images of the hand print acquired by the one or more image acquisition devices. It is noted that the light sources comprised by the illumination 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, surface light sources, and the like. The point light source may be, for example, a light band composed of a plurality of point light sources. Illustratively, at least part of the light source and the one or more image acquisition devices in the illumination system are located on the same side of the palm print acquisition area, e.g. below the palm print acquisition area. The light source located on the same side of the palm print capture area as the one or more image capture devices may be referred to as the primary light source. By way of example and not limitation, the illumination system may include an auxiliary light source in addition to the primary light source, located near the palm print acquisition area, to illuminate the palm print from a location closer to the palm print. The auxiliary light source is closer to the center of the palm print capture area than the primary light source. For example, the primary light source may be disposed below the palm print acquisition zone, and the center of gravity of the auxiliary light sources (which may be understood as the respective center of gravity of each of the auxiliary light sources) may be located at or substantially at the same level as the center of the palm print acquisition zone. At least some of the auxiliary light sources may be located at predetermined positions on both sides of the palm print capture area (a first of the sides corresponds to a first predetermined position and a second of the sides corresponds to a 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). A light source located at a predetermined position on either side of the palm print acquisition area may illuminate toward that side of the palm print acquisition area. A light source located near the fingertip position may emit light toward the fingertip position. Finger tip position refers to a position where the user's finger tip is expected to fall when the user places his finger or palm on the palm of the hand in the palm print capture zone. It will be appreciated that the position of the auxiliary light source is targeted to illuminate the hand and not affect 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.

In an exemplary embodiment, the fingerprint collection system of the present application may be non-contact, that is, the fingerprint collection area is a space, and the user may collect the fingerprint by placing part or all of the hands in the fingerprint collection area, without any entity contacting the fingerprint. Of course, alternatively, the fingerprint collection system may be a contact type fingerprint collection system, for example, a fingerprint collection system operating on a smart device that performs fingerprint collection by touching a screen with a finger.

Fig. 1 shows three image acquisition devices 112, 114 and 116. Fig. 1 furthermore shows an illumination 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 sets of light sources in a one-to-one correspondence with three image capture devices, each set of light sources including at least one blue light source and at least one green light source for illumination when its corresponding image capture device is performing image capture.

For example, the light source set may be further divided into light source subsets according to the difference of the relative positional relationship between the light sources in the light source set and the image acquisition device 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 is used as a light source subset, and the right light source is used as a light source subset. For example, in FIG. 1, the first set of light sources includes subsets of light sources 122 and 122', the second set of light sources includes subsets of light sources 124 and 124', and the third set of light sources includes subsets of light sources 126 and 126'.

It should be noted that the structure of the fingerprint acquisition system 100 shown in fig. 1 is merely exemplary and not limiting, and the fingerprint acquisition system 100 according to the embodiment of the present invention is not limited to the case 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 pickup device shown in fig. 1 and the positions of the light source subsets may also be changed as needed. For example, any one light source set may also include a single subset of light sources (e.g., the first light source set may include only light source subset 122) or more than two subsets of light sources.

Illustratively, the lighting system comprises at least one light source pair, each comprising one blue light source and one green light source. This example is a relatively desirable arrangement of light sources, which facilitates keeping each paired blue light source as close to the green light source as possible, so that the acquisition conditions of the blue and green channels of the image approach as close as possible, which helps to improve the accuracy of subsequent hand print images obtained based on both channels.

For example, in embodiments in which the illumination system comprises one or more light source sets in a one-to-one correspondence with one or more image acquisition devices, each light source set may comprise at least one light source pair, each light source pair comprising one blue light source and one green light source. Therefore, when each image acquisition device acquires images, imaging conditions of the blue channel and the green channel corresponding to the image acquisition device are enabled to be approximately consistent as much as possible. 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. If classified by color, the light sources included in the lighting system may be classified into a blue light source group and a green light source group. 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 or may not be identical. Preferably, the number of blue light sources included in the blue light source group corresponds to the number of green light sources included in the green light source group.

Illustratively, the fingerprint acquisition system 100 may further include a housing, and the one or more image acquisition devices and at least a portion of the light sources in the illumination system may be disposed inside the housing. Illustratively, a window may be provided on the housing, with a light-transmissive plate being provided on the window. The palm print collecting area can be located above the light-transmitting plate, a user places a finger in the palm print collecting area, and the illumination system below can irradiate light to the finger through the light-transmitting plate. The image acquisition device below the fingerprint acquisition area can also acquire fingerprint images of the finger through the light-transmitting plate. Of course, the embodiment in which the palm print capture area is located above the light transmissive plate is merely an example, and the position of the palm print capture area relative to at least some of the light sources in the image capture device and the illumination system may also be varied, as long as the palm print capture area is located within the imaging range of the image capture device and within the illumination range of the illumination system. In the description herein, the imaging range of any image capturing device refers to a range covered by a cone with the optical center of the lens of the image capturing device as the vertex and the viewing angle of the image capturing device as the cone angle. It should be noted that, the light-transmitting plate may be installed at a predetermined height in the housing, so as to avoid the virtual image formed by the illumination light source through the light-transmitting plate from entering the imaging range of the image acquisition device as much as possible. It will be appreciated that the illumination system may also include a light source located near the palm print capture area, that is, the illumination system may also include an auxiliary light source located above the light-transmissive plate to illuminate the hand at a location closer to 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 palm print capture area, e.g., the auxiliary light source includes a light strip consisting of point light sources on both sides of the palm print capture area and a point light source near the fingertip position.

The palm print acquisition zone may be a region of physical space having any suitable shape, such as a sphere, cube, or any other regular or irregular region, etc. By way of example and not limitation, the imaging range of one or more image acquisition devices may cover the entire palm print acquisition area, facilitating acquisition of images of the entire palm print acquisition area. After the user places the finger or palm in the palm print collecting area, the image collecting device can collect the fingerprint or palm print image of the user. The hand texture acquisition system can be used for acquiring only one type of hand texture and can also be used for acquiring a plurality of types of hand textures. For example, the fingerprint collection system may be used to collect fingerprints of only the fingertip area (including the front and side fingerprints of the finger belly), may be used to collect fingerprints of both the fingertip area and the palm of the palm, and may be used to collect fingerprints of both the fingertip area, the ridge on the finger joints other than the finger joints where the finger tips are located, and the palm of the palm. The same hand texture collection area can be shared by multiple types of hand textures, or different hand texture collection areas can be used, and the hand texture collection areas of different types of hand textures can be partially or completely overlapped.

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

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

In another embodiment, the palm print capture system 100 may include a plurality of image capture devices. In this case, alternatively, the palm print image at a plurality of angles may be acquired by a plurality of image acquisition devices. That is, the optical axes of any two image pickup devices among the plurality of image pickup devices may be at a preset angle to each other, which is not equal to 0, so as to collect the hand pattern images at different angles. When the acquired fingerprint is a fingerprint, the angles/heights of the image acquisition devices can be adjusted to acquire not only the fingerprint image on the front face of the finger belly but also the fingerprint image on the side face of the finger belly, and the implementation scheme for acquiring the fingerprint image under multiple angles is more suitable for simulating the fingerprint image obtained by rolling and stamping. It will be appreciated that the plurality of image acquisition devices may be arranged with their optical axes substantially perpendicular to the area of the hand pattern they are to acquire. For example, an optical axis of an image capturing device for capturing finger-pad front fingerprint images is perpendicular to the finger-pad front area, and an optical axis of an image capturing device for capturing finger-pad side fingerprint images is perpendicular to the finger-pad side area. When the hand texture collection system is used for collecting multiple types of hand textures, the multiple image collection devices can comprise an image collection device used for collecting the first type of hand textures and an image collection device used for collecting the second type of hand textures, and the fields of view, focal lengths, placement angles and positions of the image collection devices used for collecting the first type of hand textures and the image collection device used for collecting the second type of hand textures can be different. It will be appreciated that an image acquisition device for acquiring a palm print has a larger field of view than an image acquisition device for acquiring a fingerprint. The field of view of the image capturing device for capturing a fingerprint or palm print may refer to the field of view of a single image capturing device or may refer to the field of view of a combination of multiple image capturing 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 to preview, which may have a larger field of view than the image capture device used for capturing, e.g., a single preview image capture device field of view covering the entire palm print, and a field of view common to multiple image capture devices used for capturing covering the entire palm print. The plurality of image capturing devices may capture a plurality of palm print images of a target portion such as a finger or a palm of a user in one-to-one correspondence, and the plurality of palm print images may correspond to different portions of the target portion. For example, the image capturing devices are 3, the palm print image captured by the first image capturing device may correspond mainly to the left portion (i.e., the side area, particularly the left side area) of the finger or palm, the palm print image captured by the second image capturing device may correspond mainly to the middle portion (i.e., the front area) of the finger or palm, and the palm print image captured by the third image capturing device may correspond mainly to the right portion (i.e., the side area, particularly the right side area) of the finger or palm.

The optical axis of the image acquisition device faces to the surface of the target part where the palm print is located, for example, the palm center of the palm or the belly of the finger. For example, if it is prescribed that the user is picking up a fingerprint with the finger belly of the finger facing the ground plane, the optical axis of the image pick-up device may be arranged vertically upwards or obliquely upwards so as to be able to pick up a fingerprint of the user's finger.

In the case where the number of 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 capturing palmprints, the heights at which the centers of gravity of the plurality of image capturing devices are located may be uniform. In the case of capturing a hand print, the center of gravity of the plurality of image capturing devices may lie on one circular arc.

The processing device 130 is communicatively coupled with one or more image acquisition devices, which may be a wired or wireless connection. The processing device 130 may receive the hand print image acquired by each of the one or more image acquisition devices and process the hand print image. The processing device 130 may perform any desired processing operations on the hand print image including, but not limited to, one or more of the following: acquiring depth information from the hand vein image; and performing splicing processing and the like on the hand vein images acquired by the image acquisition devices.

By way of example and not limitation, the processing device 130 may also be communicatively connected with a 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 lighting schemes described herein. Of course, alternatively, the light sources in the lighting system may be controlled to emit light by other control means than the processing means 130. The control device may be a control device in the palm print acquisition system or may be an external control device independent of the palm print acquisition system.

The skin of different persons has different reflection, absorption and transmittance of light, and the part of the hand of the same person (hereinafter, the finger or palm is taken as an example) has different reflection, absorption and transmittance of light of different wavelengths. In addition, the fingers or palms of the same person are also different in reflection, absorption and transmission performance of light in a state of dryness, wetness, sweat or the like.

The inventors found that: when the palm print image is collected, if the green light is simply used for supplementing light, on one hand, the light reflected by the finger or the palm to the image collecting device is weakened to reduce the contrast of the image, and on the other hand, the light absorbed by the finger or the palm can generate fluorescence and phosphorescence to blur the collected image because the finger or the palm absorbs the green light; however, when the blue light is used alone, the blue light is absorbed by the finger or palm, the light reflected by the finger or palm to the image acquisition device is strong, the light is easily overexposed for a person with shallow skin, and in addition, when the hand is overdry, dead skin or sweat and other liquid is reflected strongly, the contrast is easily deteriorated. However, both blue and green light have their own advantages. For example, the contrast between ridges and valleys of a fingerprint or palm print can be improved under the condition of blue light supplementing, and the method is suitable for shallow fingerprint people; and fingers that are too dry or too wet are photographed more clearly in the case of green light supplement.

Therefore, the inventor chooses to supplement light by using light sources with two colors of blue and green at the same time, so that the two light sources can complement each other, and a high-quality palm print image can be obtained relatively easily through processing as long as a clear image can be acquired under the light of one color. Therefore, the scheme of supplementing light through the light sources with blue and green colors when collecting the hand patterns can enlarge the applicability of the hand pattern collecting system to different skin states, thereby being beneficial to meeting the collecting requirements of various crowds.

In order to avoid the mutual influence of the blue-green light, the wavelength division of the blue-green light source can be set as large as possible, i.e. a blue light source with a shorter wavelength (violet bias) and a green light source with a shorter wavelength (yellow bias) can be selected as much as possible. By way of example and not limitation, the blue light described herein may be light having a wavelength less than 430nm, such as 405nm, and the green light may be light having a wavelength greater than 540nm, such as 560 nm.

In a particular embodiment, the illumination system may include one or more light source sets, each light source set including at least one blue light source and at least one green light source, the one or more light source sets being in one-to-one correspondence with the one or more image capture devices.

In this embodiment, the light source set corresponding to any one of the image capturing devices 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 can emit light, and the other light source sets do not emit light. The light supplementing light sources corresponding to the image acquisition devices are distributed to each image acquisition device, so that the image acquisition devices and the light sources can be conveniently controlled and managed, and the mutual interference of different light sources during image acquisition can be conveniently avoided.

By way of example and not limitation, for any one of the one or more light source sets, the direction in which light rays are emitted by the light sources of that light source set may be substantially perpendicular to the palm print area acquired when the light sources of that light source set are in the on state. Thus, the light rays are approximately perpendicular to the hand grain area, which is beneficial to ensuring that the grain and the ridge of the hand grain can be accurately presented in the hand grain image. When a plurality of image capturing devices may be arranged with their optical axes substantially perpendicular to the area of the hand pattern they are to capture, the direction of light emitted by the light sources in each set of light sources 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 set of light sources sufficiently close together with their corresponding image capturing devices.

With continued reference to fig. 1, the optical axes 1122, 1142, and 1162 of the image capture devices 112, 114, and 116, respectively, are shown. As can be seen from fig. 1, the directions of the light rays emitted by the light sources in each light source set are parallel to the optical axis direction of the corresponding acquisition device. It is noted that parallelism as described herein does not necessarily require that the parallel objects be absolutely parallel to each other, but may be substantially parallel. For example, the parallel may refer to that an included angle between a parallel object (in this embodiment, a direction in which the light source emits light and an optical axis direction of the corresponding image capturing device or any two light rays 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 an embodiment of the invention, the lighting system comprises at least one light source pair, each light source pair comprising one blue light source and one green light source, the distance between the blue light source and the green light source within the same light source pair being smaller than a preset distance threshold.

When the 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 favorable to be ensured to be approximately consistent. The consistency of imaging conditions of the blue channel and the green channel is beneficial to improving the fusion effect of the blue channel image and the green channel image when the subsequent images are fused.

Such embodiments are merely exemplary and not limiting of the present invention and the light sources in the lighting system may all be unpaired or the lighting system may include a light source pair and an unpaired light source.

Each set of light sources may comprise at least one light source pair. 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 spaced as close together as possible to further ensure that the imaging conditions of the blue and green channels are approximately uniform. For example, referring back to FIG. 1, any of the light source subsets (e.g., 122', 124', 126 ') shown therein may include at least one light source pair such that the blue light source and the green light source in the light source subset can be conveniently disposed 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 an embodiment of the invention, the illumination system is located outside the imaging range of one or more of the image acquisition devices. In embodiments where the illumination system comprises one or more sets of light sources, the set of light sources corresponding to any one image acquisition device may be located outside the imaging range of that image acquisition device.

The light source may be positioned at any suitable location around the image capture device so long as it does not interfere with imaging by the image capture device. The light source set corresponding to any image acquisition device is arranged outside the imaging range of the image acquisition device, so that the phenomenon that the light source obstructs the image acquisition device to acquire the images of the hand veins can be effectively avoided.

According to the embodiment of the invention, 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 hand pattern acquisition area facing the one or more image acquisition devices, the optical axis of the second image acquisition device forms 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 forms a second preset included angle with the optical axis of the first image acquisition device.

The plane of the palm print capture area facing the one or more image capture devices may be, for example, a plane parallel to the plane of the mask described above. In the case where it is prescribed that the palm center of the palm or the palm of the finger should be oriented toward the ground plane when the user is collecting the palm print, the plane of the palm print collection area oriented toward the one or more image collection devices may be parallel to the ground plane. At this time, the optical axes of the first image pickup device may be vertically upward, and the optical axes of the second image pickup device and the third image pickup device may be obliquely upward.

Any one of the first preset included angle and the second preset included angle may be set to any suitable value according to needs, and the present invention is not limited thereto. The first preset angle and the second preset angle may be the same or different. The first preset included angle may be in the range of 0 to 45 degrees, and the second preset included angle may be in the range of 0 to 45 degrees, for example.

According to the embodiment of the invention, the optical axes of the first image acquisition device, the second image acquisition device and the third image acquisition device are positioned in the same plane.

The optical axes of the three image acquisition devices are positioned in the same plane and are not parallel to each other, so that the arrangement is simple, and the images of a plurality of different parts of the target parts such as fingers or palms can be conveniently acquired.

According to an embodiment of the present invention, the fingerprint acquisition system may further include: the structured light projector is used for emitting structured light to the palm print collecting area; the processing device can process the hand image acquired by the one or more image acquisition devices in the following way: and respectively extracting gray images of channels corresponding to the structured light from the hand vein images acquired by the one or more image acquisition devices, and determining hand vein depth information based on the extracted structured light images.

It will be appreciated that the structured light projector emits structured light for encoding as opposed to illumination sources that are not used for encoding, but are used only for illumination.

Fig. 2 shows a schematic diagram of a palm print acquisition system 100 and associated fingers 200 and palm print acquisition area 300 according to one embodiment of the invention. Fig. 2 shows that the hand pattern acquisition system 100 further comprises a structured light projector 140. Fig. 1 may be understood as a front view of the palm print acquisition system 100, while fig. 2 may be understood as a left view of the palm print acquisition system 100. It should be noted that fig. 2 illustrates only a single image capture device 114 as an example, and those skilled in the art will appreciate the location of other image capture devices in fig. 2.

The configuration of the fingerprint acquisition system 100 shown in fig. 2 is merely exemplary and not limiting, and the fingerprint acquisition system 100 according to the embodiment of the present invention is not limited to the case shown in fig. 2. For example, fig. 2 shows that the structured light projector 140 is located on a side closer to the root of the finger, bounded by a specific cross section 302, where the specific cross section 302 is the cross section of the finger 200 that overlaps the central axis of the palm print acquisition zone 300, when the head (the location from which light is emitted) of the structured light projector 140 is further from the horizontal distance of the root of the finger than the tail (the location opposite the head). The above-described arrangement of structured light projector 140 is only an example, and it may also be located on the side of the specific cross section 302 that is further away from the root of the finger, i.e. the head of structured light projector 140 may also be closer to the horizontal distance of the root of the finger than the tail. In fact, structured light projector 140 may be positioned at any suitable location as desired, so long as it does not interfere with imaging by the image acquisition device and is capable of illuminating the hand pattern acquisition region.

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 be substantially coincident with the height at which the combined center of gravity or lowest center of gravity of the one or more image capture devices is located. This facilitates a more compact arrangement of the components of the palm print capture system, which is advantageous in reducing the volume of the device. 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 one or more image capture devices, which may ensure that the light projected 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 fingerprint acquisition, where the target site is small, the height at which the center of gravity of the structured light projector 140 is located may be set to be substantially identical to the height at which the integrated center of gravity or lowest center of gravity of one or more image acquisition devices is located. In the case of collecting palmprints, where the target site is large, the center of gravity of the structured light projector 140 may be at a lower elevation than the combined center of gravity or lowest center of gravity of one or more image collection devices.

The gray level image of the channel corresponding to the structured light extracted from any one of the hand pattern images is the structured light image corresponding to the hand pattern image. It is understood that the structured light image contains depth information corresponding to each pixel in the original fingerprint image. Therefore, by the structured light projector, it is possible to further acquire the palm print depth information of the target portion such as the finger or palm. And the hand pattern depth information is acquired, so that the subsequent simulated stamping hand pattern image is convenient. At present, many occasions may need to be applied to fingerprint images acquired in a stamping mode, so that the acquired fingerprint images can be correctly unfolded into two-dimensional images by adding a structured light scheme, and the fingerprint images are compatible with the fingerprint images acquired in the stamping mode in the subsequent comparison process, so that the application scene of the fingerprint acquisition system is enlarged.

By way of example and not limitation, since the supplemental light is of two colors, the structured light may be selected as much as possible to have a color that differs significantly from the blue-green color, such as red, etc., in order to reduce interference with the blue-green channel. 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 into blue, green and red colors, which is beneficial to conveniently extracting images of different channels. Of course, the structural light does not have to be red, and the influence of the structural light in the blue-green channel can be removed in an image processing mode.

According to the embodiment of the invention, the direction of the light rays emitted by the structured light projector forms a third preset angle with the plane of the optical axis of one or more image acquisition devices.

The third preset angle may be set to any suitable value as needed, 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 the image pickup devices in fig. 2 are in the same plane and that the 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 in which the structured light projector 140 emits light is at an angle to the plane in which the optical axis of the image acquisition device lies. The mode of arranging the structured light projector on the side face 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 interference with 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 is convenient for arranging the structured light projector at the height close to that of the image acquisition device, and is beneficial to realizing more compact layout in the palm print acquisition system.

According to an embodiment of the present invention, the fingerprint acquisition system 100 may further include a housing, wherein the one or more image acquisition devices and the illumination system are disposed in the housing, and a window is disposed on the housing at a position facing the fingerprint acquisition area, and a light-transmitting plate is disposed on the window.

The embodiments 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 are described above, and will not be described herein. The light-transmitting panel may be implemented using any suitable material, including, but not limited to, glass, etc. The glass may be, for example, glass with an anti-reflection coating. The light-transmitting plate can play a role in preventing water and dust, helps to protect a main body structure in the palm print collecting system, and prolongs the service life of equipment.

According to an embodiment of the present invention, the hand print collection system 100 may further include a limiting member defining a hand print collection area, the proximal end of the limiting member being provided with an inlet to allow part or all of a user's hand to extend through the inlet into the hand print collection area; the distal end of the limiting member is provided with a stopper portion located at a predetermined position of the palm print collecting area along the extending direction to limit a portion or all of the user's hand from extending into the position within the palm print collecting area.

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

Fig. 3 shows a schematic diagram of a portion of a palm print acquisition system according to one embodiment of the invention. In fig. 3, the stop member 150 is shown, and the inlet 152 and stop 154 of the stop member 150 are shown. The area between the entrance 152 of the spacing member 150 and the stop 154 may be defined as the palm print capture area 300. A target site such as a user's finger or palm may extend through the inlet 152 into the palm print acquisition area 300. The stop portion 154 can limit the limit position that can be reached by the target portion such as a finger or a palm of the user, so as to prevent the target portion such as the finger or the palm of the user from extending too far. The limiting member 150 may conveniently guide the user to place the target portion such as a finger or palm at a correct position, so as to ensure that a portion of the target portion that is more suitable for detection (e.g., the first knuckle of the finger closest to the fingertip) may fall into the palm print collecting zone.

According to an embodiment of the present invention, the fingerprint collection system 100 may further include a light shielding member, where at least part of the light sources in the light shielding member and the illumination system are respectively located at two opposite sides of the fingerprint collection area.

Referring to fig. 3, a shade member 160 is shown that is positioned on opposite sides of the palm print capture area 300 from at least a portion of the light sources in the illumination system. The shading component is located above the palm print collecting area, and at least part of the light sources in the lighting system are located below the palm print collecting area. The light shielding component 160 can prevent the illumination emitted by the light source from affecting the user experience, and can prevent the external stray light from irradiating the inside of the hand pattern collecting area so as to interfere with the collection of the hand patterns.

In the case where the fingerprint acquisition system includes a light shielding member and a light transmissive plate, the fingerprint acquisition area may be at least a portion of an area located between the light shielding member and the light transmissive plate.

Fig. 4 shows a schematic diagram of a portion of the structure of a palm print acquisition system 100 and associated finger and palm print acquisition areas in accordance with one embodiment of the invention. Note that fig. 4 is a schematic view, and does not show the actual shape or size of each component. Referring to fig. 4, there is shown a light shield 160 and a light transmissive plate 170 with a palm print acquisition area 300 disposed therebetween. In addition, fig. 4 also shows two sets of auxiliary light sources 1281 and 1282 on either side of the palm print acquisition area 300 and auxiliary light source 1283 near the fingertip position of the palm print acquisition area 300. In the example shown in fig. 4, the two sets of auxiliary light sources 1281 and 1282 on both sides of the palm print capture area 300 are each a light strip, and the auxiliary light source 1283 near the fingertip position of the palm print capture area 300 is a point light source, but this is merely an example, and other implementations of the auxiliary light sources are possible. Further, note that, for convenience of distinction, in fig. 4, the finger 200 is indicated by a broken line.

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

Referring to fig. 3, a connection 156 in the spacing member 150 is shown connecting the inlet 152 and the stop 154. The upper surface of the connection portion 156 may be adhered to the lower surface of the light shielding portion 160, so that light emitted from the light source may be better prevented from being dissipated to the outside and stray light from the outside may be better prevented from being irradiated to the moire collecting region.

According to another aspect of the present invention, a method for collecting handprint implemented by the handprint collecting system 100 is provided. The method for collecting the handprint comprises the following steps: when the blue light source group emits light in a blue light emitting scheme and the green light source group emits light in a green light emitting scheme, acquiring images of the hand print acquisition area through one or more image acquisition devices to acquire hand print images acquired by the one or more image acquisition devices, wherein at least one hand print image is acquired under the condition that a blue light source with luminous intensity being not 0 exists in the blue light source group, and at least one hand print image is acquired under the condition that a green light source with luminous intensity being not 0 exists in the green light source group; the blue light source group comprises one or more blue light sources, the green light source group comprises one or more green light sources, the blue light emitting scheme is used for representing the light emitting intensity of each blue light source, and the green light emitting scheme is used for representing the light emitting intensity of each green light source; at the time of collection, the luminous intensity of at least one light source is not 0.

The structure and arrangement of the illumination system and the image capturing device may be understood in conjunction with the above description, and are not repeated here.

As described above, the illumination system may be divided into two groups according to the light source colors, i.e., a blue light source group and a green light source group. The set of blue light sources may comprise all blue light sources in the illumination system and the set of green light sources may comprise all green light sources in the illumination system.

For each image acquisition device in the palm print acquisition system, at least one palm print image in the acquired palm print images is only required to be acquired under the condition that a blue light source with the luminous intensity not being 0 exists in a blue light source group, at least one palm print image is only required to be acquired under the condition that a green light source with the luminous intensity not being 0 exists in a green light source group, and the time sequence of the image acquisition devices for acquiring the images and the time sequence of the light emission of all the light sources in the lighting system can be set according to requirements.

The "at least one hand print image" acquired when the light emission intensity of the blue light source is not 0 may be the same as the "at least one hand print image" acquired when the light emission intensity of the green light source is not 0. For example, for any one of the image capturing devices X, two hand images may be captured, the first being captured with the light emission intensity of at least one blue light source being other than 0 and the light emission intensities of all green light sources being 0, and the second being captured with the light emission intensity of at least one green light source being other than 0 and the light emission intensities of all blue light sources being 0. For another example, the image capturing device X may capture only one hand image, which may be captured in a case where the light emission intensity of at least one blue light source is not 0 and the light emission intensity of at least one green light source is not 0. For another example, the image capturing device X may also capture three hand images, the first captured when the light emission intensity of at least one blue light source is not 0 and the light emission intensities of all green light sources are 0, the second captured when the light emission intensity of at least one blue light source is not 0 and the light emission intensity of at least one green light source is not 0, and the third captured when the light emission intensity of at least one green light source is not 0 and the light emission intensities of all blue light sources are 0. The above acquisition schemes of the image acquisition device X are all feasible, and of course, other numbers of images can be acquired and other light emitting modes can be adopted, which will not be repeated here.

For each acquisition of one or more image acquisition devices, the sub-acquisition corresponds to one blue light emitting scheme and one green light emitting scheme, and the hand print image obtained by the sub-acquisition also corresponds to the one blue light emitting scheme and the one green light emitting scheme. Each blue light emission scheme is used to characterize the light emission intensity of a respective light source in the set of blue light sources, and each green light emission scheme is used to characterize the light emission intensity of a respective light source in the set of green light sources.

The relationship between the light emission and the image acquisition of the light source according to the light emission scheme is described below by taking the blue light source group as an example, and the green light source group is similar to the blue light source group and is not repeated herein. Assuming that the blue light source group includes three blue light sources B1, B2 and B3 in total, and the light emission intensity of each light source is divided into only two steps, one is that the intensity reaches the maximum, and the other is that the intensity is 0, there are eight blue light emission schemes in total (i.e. at most) theoretically. Assuming that the emission intensity of each light source reaches the maximum, indicated by the numeral "1", and the intensity of 0 is indicated by the numeral "0", the above eight blue emission schemes may be indicated as 000, 001, 010, 100, 011, 101, 110, 111. For the image acquisition device, part or all of the eight blue light emitting schemes can be adopted to emit light sequentially, and corresponding hand pattern images can be acquired under each light emitting scheme. For example, for the image capturing device, six blue light emitting schemes are adopted to emit light in any order, and each time the blue light source group emits light according to any blue light emitting scheme, at least part of the image capturing devices in the one or more image capturing devices capture a corresponding palm print image. It should be noted that the same blue light emitting scheme may appear once or more times, for example, any one of the above six blue light emitting schemes P appears three times, and the other blue light emitting schemes appear once, and finally eight images may be acquired and obtained, where the light emitting schemes corresponding to the three images are all blue light emitting schemes P.

It should be noted that, for the image capturing device, no matter what blue light emission scheme and green light emission scheme are adopted for each capturing, the light emission intensity of at least one light source is not 0.

Although the above description has been made taking the case that the light emission intensity of each light source is divided into two steps, it will be understood that the light emission intensity of each light source may have more steps, and the steps of the light emission intensities of any two different light sources may be the same or different, and these may be set arbitrarily. In the case where the light emission intensity of the blue/green light source has more steps, the maximum possible number of blue/green light emission schemes may also be increased, but the blue/green light emission scheme that is ultimately used to supplement light for any one image pickup device may be selected as desired, and may include all or only a part of all possible blue/green light emission schemes.

According to the method for collecting the handprint, for each image collecting device, at least one of the collected handprint images is collected under the condition that the luminous intensity of the blue light source is not 0, and at least one of the collected handprint images is collected under the condition that the luminous intensity of the green light source is not 0. Thus, in this method, a blue light source and a green light source may be employed together to supplement the image capture device as each image capture device captures an image. The applicability of the palm print collecting method to different skin states can be enlarged, so that the collecting requirements of various crowds can be met.

According to an embodiment of the invention, the collecting includes multiple times, at least two times of collecting the blue light emitting schemes are different, and/or at least two times of collecting the green light emitting schemes are different.

The operation of one or more image acquisition devices to acquire images of the hand print may be performed a plurality of times. The image capturing devices that perform any two different capturing operations may be the same or different. When the lighting system is controlled to emit light, the lighting scheme corresponding to at least two acquisitions in the plurality of acquisitions can be changed, and the changed lighting scheme can be a blue lighting scheme, a green lighting scheme or both the blue lighting scheme and the green lighting scheme. In the case where both the blue light emission scheme and the green light emission scheme are changed, at least two acquisitions corresponding to the change in the blue light emission scheme and at least two acquisitions corresponding to the change in the green light emission scheme may be completely different, completely the same, or only a part of the acquisitions may be the same.

The at least two acquisitions of different blue light emission schemes may be at least two consecutive acquisitions or at least two acquisitions of partial or complete discontinuity. Similarly, the at least two acquisitions differing in green lighting scheme may be at least two acquisitions that are consecutive, or may be at least two acquisitions that are partially or entirely discontinuous.

The collection condition faced by the palm print collection system is complex and can change at any time, for example, the skin states of different people are different, the positions of the target positions placed by different people are different, and even the same person, the skin states of different times and the positions of the target positions placed by different people can also change. The lighting conditions required for obtaining the fingerprint image with better quality can be different according to different acquisition conditions. If the lighting scheme is stable and unchanged in the process of collecting the hand vein image by the image collecting device, only the hand vein image with single quality can be collected, and if the current lighting scheme is not suitable for the collecting condition of the current user, the finally obtained hand vein collecting effect may be unsatisfactory. Therefore, in the process of acquiring the hand vein image by the image acquisition device, the luminous scheme is changed to a certain extent, so that the quality of the acquired hand vein image is also changed to a certain extent, the limitation of a single hand vein image can be made up to a certain extent, and the acquisition of a better hand vein acquisition effect is facilitated.

According to an embodiment of the invention, the acquisition includes multiple times, wherein the blue light emitting schemes corresponding to each of the multiple times of acquisition are different, and/or the green light emitting schemes corresponding to each of the multiple times of acquisition are different.

The embodiment in which the corresponding light emitting scheme is changed every two acquisitions has been described above, and the implementation manner of this embodiment may be understood in conjunction with the above description, which is not repeated here. The luminous schemes corresponding to the two collection are changed, and the luminous schemes in the mode are rich in change, so that the collection effect is improved better.

According to the embodiment of the invention, the corresponding blue light emitting scheme or green light emitting scheme is acquired at least twice.

In at least two acquisitions, the blue light emission scheme may be made unchanged, only the green light emission scheme may be changed, or the green light emission scheme may be made unchanged, only the blue light emission scheme may be changed. By adopting the embodiment, the variation span of the lighting scheme is smaller as a whole, and the hand pattern images acquired at different moments are conveniently aligned based on the same color lighting scheme which is unchanged.

According to an embodiment of the invention, there are no two acquisitions corresponding to the same blue light emission scheme and the same green light emission scheme.

For the two acquisitions, if the blue light emitting scheme and the green light emitting scheme are identical, two hand pattern images with basically consistent quality are acquired, which is of little significance. For the image acquisition device, all the acquisition operations of the image acquisition device respectively correspond to different blue light-emitting schemes and/or green light-emitting schemes, so that the light-emitting schemes can be changed as much as possible in the whole acquisition process of the image acquisition device, and more hand vein images with different qualities are obtained. This helps to increase the probability of occurrence of a lighting scheme more adapted to the current acquisition situation, helps to increase the probability of obtaining a high quality palm print image, and further helps to increase the final palm print acquisition effect.

According to an embodiment of the present invention, when the blue light source group emits light in a blue light emission scheme and the green light source group emits light in a green light emission scheme, capturing an image of a palm print capturing area by one or more image capturing devices includes: at a first moment, when the blue light source group emits light according to a first blue light emitting scheme and the green light source group emits light according to a first green light emitting scheme, acquiring images of a palm print acquisition area through at least part of image acquisition devices in one or more image acquisition devices; at a second moment, when the blue light source group emits light in a second blue light emitting scheme and the green light source group emits light in a second green light emitting scheme, acquiring images of the hand print acquisition area through at least part of the image acquisition devices in the one or more image acquisition devices, wherein the first blue light emitting scheme and the second blue light emitting scheme are selected from a blue light emitting scheme set, and the first green light emitting scheme and the second green light emitting scheme are selected from a green light emitting scheme set; the blue light emitting scheme set comprises w blue light emitting schemes, wherein the maximum value of w is 2 ^k1 At 2 ^k1 In the blue light emitting scheme, the light emitting intensity of any blue light source is divided into 0 and non-0 steps; the green light emitting scheme set comprises p green light emitting schemes, wherein the maximum value of p is 2 ^k2 At 2 ^k2 In the green light emitting scheme, the light emitting intensity of any green light source is divided into 0 and non-0 steps; k1 is the total number of blue light sources in the lighting system, and k2 is the total number of green light sources in the lighting system; w is an integer greater than or equal to 2 and/or p is an integer greater than or equal to 2The method comprises the steps of carrying out a first treatment on the surface of the The first blue light emitting scheme is different from the second blue light emitting scheme, and/or the first green light emitting scheme is different from the second green light emitting scheme.

In this embodiment, the luminous intensity of each light source in the lighting system is divided into two steps, one is that the luminous intensity is not 0, and one is that the luminous intensity is 0. Thus, at most 2 may be included in the set of blue light emitting schemes ^k1 A blue light emitting scheme. Similarly, up to 2 may be included in the set of green lighting schemes ^k2 -1 green lighting scheme.

For any light source, when it is in a gear position with a luminous intensity other than 0, the value of the luminous intensity may be any value, for example, the maximum luminous intensity of the light source, or half the maximum luminous intensity of the light source, etc.

As described above, the lighting scheme may be changed during the process of capturing an image by the image capturing apparatus. In this embodiment, the first time and the second time may emit light according to different blue light emission schemes and/or different green light emission schemes, respectively. The image capturing devices that capture images of the hand print at the first moment and the second moment may be identical to each other, completely different or partially identical.

The present embodiment can be understood in conjunction with the above description about the change of the light emitting scheme, and will not be repeated.

According to an embodiment of the present invention, the first blue light emitting scheme is the same as the second blue light emitting scheme, or the first green light emitting scheme is the same as the second green light emitting scheme.

It is assumed hereinafter that the blue light source group includes three blue light sources B1, B2, B3, the green light source group includes three green light sources G1, G2, G3, and that the light emission intensity of each light source is not 0 and is indicated by the numeral "1", and the intensity is 0 and is indicated by the numeral "0". At the first moment, the adopted first blue light emitting scheme may be 100, and the first green light emitting scheme may be 111; and at the second time, the second blue light emitting scheme adopted may still be 100, and the second green light emitting scheme may be changed to 011. In this embodiment, the blue light emission scheme is changed, so that the green light emission scheme is unchanged, whereas the green light emission scheme is changed, so that the blue light emission scheme is unchanged.

The advantages of embodiments in which the blue light emission scheme and/or the green light emission scheme is unchanged in at least two acquisitions are described above, and are not described here again.

According to an embodiment of the present invention, when the blue light source group emits light in a blue light emission scheme and the green light source group emits light in a green light emission scheme, the capturing the image of the palm print capturing area by the one or more image capturing devices further includes: at a third moment, when the blue light source group emits light according to a third blue light emitting scheme and the green light source group emits light according to a third green light emitting scheme, acquiring images of the hand print acquisition area through at least part of the image acquisition devices in the one or more image acquisition devices, wherein the third blue light emitting scheme is selected from a blue light emitting scheme set, and the third green light emitting scheme is selected from a green light emitting scheme set; the third blue light emitting scheme is different from at least one of the first blue light emitting scheme and the second blue light emitting scheme; and/or the third green light emitting scheme is different from at least one of the first green light emitting scheme and the second green light emitting scheme; there are no two acquisitions corresponding to the same blue light emission scheme and the same green light emission scheme.

The image capturing device for capturing the images of the hand prints at the third moment may be identical to the image capturing device for capturing the images of the hand prints at the first moment, completely different or partially identical. Similarly, the image capturing device for capturing the images of the hand print at the third moment may be identical to the image capturing device for capturing the images of the hand print at the second moment, completely different or partially identical.

In this embodiment, a third acquisition is added. In the third acquisition, the blue light emission scheme or the green light emission scheme may be changed from at least one of the previous two acquisitions.

According to the embodiment of the invention, the light emitting scheme simultaneously meets the first condition and the second condition; the first condition includes: the first blue light emitting scheme is the same as the second blue light emitting scheme, or the first green light emitting scheme is the same as the second green light emitting scheme; the second condition includes: the third blue light emitting scheme is the same as the first blue light emitting scheme, or the third blue light emitting scheme is the same as the second blue light emitting scheme, or the third green light emitting scheme is the same as the first green light emitting scheme, or the third green light emitting scheme is the same as the second green light emitting scheme.

In the case where the first blue light emitting scheme is the same as the second blue light emitting scheme, the third blue light emitting scheme is different from the first blue light emitting scheme and the second blue light emitting scheme, the first green light emitting scheme is different from the second green light emitting scheme, and the third green light emitting scheme is the same as the first green light emitting scheme or the second green light emitting scheme. In contrast, in the case where the first green light emitting scheme is the same as the second green light emitting scheme, the third green light emitting scheme is different from the first green light emitting scheme and the second green light emitting scheme, the first blue light emitting scheme is different from the second blue light emitting scheme, and the third blue light emitting scheme is the same as the first blue light emitting scheme or the second blue light emitting scheme.

That is, in the three acquisitions, the blue light emission scheme is changed once and the green light emission scheme is changed once. Thus, the hand pattern image under the condition of richer luminescence is convenient to collect.

According to an embodiment of the invention, the number of image acquisition devices in the one or more image acquisition devices is greater than 1, and all image acquisition devices are used for each acquisition.

When each acquisition is carried out, all the image acquisition devices are enabled to acquire the hand image together, so that all the acquisitions can be completed only by finishing the sequential light emission according to all the required light emission schemes. This acquisition scheme is relatively efficient.

According to the embodiment of the invention, the number of the image acquisition devices in the one or more image acquisition devices is larger than 1, and the image acquisition devices used for at least two times of acquisition in multiple times are not identical.

For example, referring to fig. 1, it is assumed that an image pickup device located at the center belongs to a first group of image pickup devices, and two image pickup devices located at both sides belong to a second group of image pickup devices. The image may be acquired by a first set of image acquisition devices at a first time and by a second set of image acquisition devices at a second time. Although images are acquired separately at different moments by different image acquisition devices, the images of the hand prints acquired by the different image acquisition devices can still be spliced. This separate acquisition scheme facilitates avoiding light sources corresponding to other image acquisition devices from interfering with the acquisition of the current image acquisition device.

According to the embodiment of the invention, 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 hand pattern acquisition area facing the one or more image acquisition devices, the optical axis of the second image acquisition device forms 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 forms a second preset included angle with the optical axis of the first image acquisition device; the illumination system comprises one or more light source sets, each light source set comprises at least one blue light source and at least one green light source, and the one or more light source sets are in one-to-one correspondence with the one or more image acquisition devices; when the blue light source group emits light in a blue light emitting scheme and the green light source group emits light in a green light emitting scheme, the capturing the image of the palm print capturing area by the one or more image capturing devices includes: at a first moment, when the blue light source group emits light according to a first blue light emitting scheme and the green light source group emits light according to a first green light emitting scheme, acquiring an image of a palm print acquisition area through a first group of image acquisition devices; at a second moment, when the blue light source group emits light according to a second blue light emitting scheme and the green light source group emits light according to a second green light emitting scheme, acquiring images of the hand pattern acquisition area through a second group of image acquisition devices, wherein the first group of image acquisition devices are one of the first image acquisition devices and the angle image acquisition devices, and the second group of image acquisition devices are the other one of the first image acquisition devices and the angle image acquisition devices; the angle image acquisition device comprises a second image acquisition device and a third image acquisition device, and the first blue light emission scheme is that the luminous intensity of a blue light source corresponding to the image acquisition device for acquisition at the first moment in the blue light source group is not 0; the first green light emitting scheme is that the light emitting intensity of the green light source corresponding to the image acquisition device for acquiring at the first moment in the green light source group is not 0; the second blue light emitting scheme is that the light emitting intensity of the blue light source corresponding to the image acquisition device for acquiring at the second moment in the blue light source group is not 0; the second green light emitting scheme is that the light emitting intensity of the green light source corresponding to the image acquisition device for acquiring at the second moment in the green light source group is not 0.

The arrangement of the first image capturing device, the second image capturing device and the third image capturing device has been described above, and will not be described in detail here. In addition, the embodiment in which the illumination system includes the light source sets and the light source sets are in one-to-one correspondence with the image capturing device is described above, and will not be described herein.

As described above, the first image pickup device, the second image pickup device, and the third image pickup device may be divided into two groups, the image pickup device located at the center is one group, and the two image pickup devices located at both sides are the other group. When any group of image acquisition devices acquire images, the luminous intensity of the light sources in the corresponding light source set is not 0, and the luminous intensities of the light sources in other light source sets are all 0.

Because the light source set at the center is closer to the light source sets at the left and right sides, the image acquisition of the corresponding image acquisition devices is easier to interfere with each other, so that it is preferable to make the light source set at the center emit light asynchronously with the light source sets at the two sides, that is, emit light at different times. This helps to obtain a more accurate image of the hand print.

In addition, the light source sets on the two sides are relatively far away from each other, so that the light source sets on the two sides can be optionally made to emit light synchronously, and the hand pattern collection time can be shortened as much as possible. Of course, alternatively, it is also possible to further asynchronously illuminate the sets of light sources located on both sides. Thus, the interference of the adjacent light sources to the image acquisition device can be avoided as much as possible.

The above-mentioned scheme for asynchronously lighting the first group of light source sets and the second group of light source sets can be applied to the situation that the light source corresponding to the first group of image acquisition devices affects the image acquisition of the second group of image acquisition devices and/or the light source corresponding to the second group of image acquisition devices affects the image acquisition of the first group of image acquisition devices.

By way of example and not limitation, the time difference between the first time instant and the second time instant may be less than a preset time threshold. The preset time threshold may be set to any suitable value as needed, and the present invention is not limited thereto. For example, the preset time threshold may be 25ms.

In view of the shake of the finger or palm, in order to reduce the difficulty in stitching together images of different image acquisition devices in the following, the time interval between two light source sets that emit light asynchronously is set as short as possible, and this short time is preferably not more than 25ms. The asynchronous light-emitting mode is particularly suitable for light-emitting tube modules packaged together.

According to an embodiment of the present invention, at a first moment, when a blue light source group emits light according to a first blue light emission scheme and a green light source group emits light according to a first green light emission scheme, an image of a palm print acquisition area is acquired by a first group image acquisition device, including: transmitting, by the processing device, a trigger signal to the first group of image acquisition devices at a first time and a light emission control signal to a first group of light source sets corresponding to the first group of image acquisition devices; at a second moment, when the blue light source group emits light according to a second blue light emitting scheme and the green light source group emits light according to a second green light emitting scheme, acquiring an image of the palm print acquisition area by the second group of image acquisition devices, including: transmitting, by the processing device, a trigger signal to the second group of image acquisition devices at a second time and a light emission control signal to a second group of light source sets corresponding to the second group of image acquisition devices; the triggering signal is used for triggering the corresponding image acquisition device to start acquiring images, the light-emitting control signal is used for controlling the corresponding light source set to emit light with non-0 intensity, and the time difference between the first moment and the second moment is equal to the sum of the acquisition duration of the first group of image acquisition devices and the preset delay duration.

By way of example and not limitation, the image acquisition by each image acquisition device and the illumination by each light source may be controlled by the processing device 130. The processing device 130 may control the image capturing device and the corresponding light source set to start working synchronously by sending the trigger signal and the light emission control signal to the image capturing device and the corresponding light source set simultaneously.

In an embodiment in which the different sets of light sources emit light asynchronously and the different sets of image capturing devices collect images asynchronously, the processing device 130 may first control the first set of image capturing devices and the first set of light sources to start working by sending the trigger signal and the light emission control signal synchronously, then complete the capturing after the capturing period of the first set of image capturing devices, and then start to control the second set of image capturing devices and the second set of light sources to start working by sending the trigger signal and the light emission control signal synchronously after a delay time (i.e. a preset delay time). The acquisition duration of the image acquisition means is typically relatively short, e.g. 2ms. The time delay period may be set smaller, and the sum of the time delay period and the acquisition period of the first group of image acquisition apparatuses is smaller than the above-described preset time threshold.

According to an embodiment of the invention, the illumination system comprises one or more light source sets, each light source set comprises at least one blue light source and at least one green light source, the one or more light source sets are in one-to-one correspondence with the one or more image acquisition devices, for any one of the one or more light source sets, the blue light source and the green light source in the light source set emit light synchronously, and the light emission periods of the blue light source and the green light source in the light source set are within the effective exposure period of the corresponding image acquisition device.

The light emission period of the light source refers to a period in which the light emission intensity of the light source is not 0. The exposure mode of any one of the one or more image capturing devices may be global exposure or line exposure. In the case where the current image pickup device employs global exposure, the exposure period of all lines in each frame image picked up by the current image pickup device is uniform, which may be referred to as an effective exposure period. The light emission period of each light source in the light source set corresponding to the current image acquisition device only needs to be within the effective exposure period. The light emission period of the light sources in the set of light sources corresponding to the current image acquisition device may be shorter than or equal to the effective exposure period at the time of global exposure.

In the case where the current image capture device employs line exposure, the effective exposure period may be an exposure period shared by all lines in each frame of image. The line exposure can be further divided into at least two exposure modes, one is line exposure in which initial time synchronization is performed and one is line exposure in which initial time synchronization is not performed.

Fig. 5 shows a schematic diagram of image acquisition and light source emission timing according to one embodiment of the invention. The line exposure pattern shown in fig. 5 is synchronized over an initial time, i.e., the initial time of exposure is uniform for each line, but the end time is different. For example, the total exposure time is 15 seconds, the exposure time of the first line is 1-10 seconds, the exposure time of the second line is 1-11 seconds, the exposure time of the third line is 1-12 seconds … …, and the exposure time of the sixth line is 1-15 seconds. The effective exposure period at this time is 1 st to 10 seconds, and thus the light emission period of the light source can be set within 1 st to 10 seconds. The total duration of the light source having the luminous intensity other than 0 may be equal to or shorter than 10 seconds.

The line exposure without initial time synchronization is only different from the example shown in fig. 5 in initial time, and other times such as the end time of each line exposure and the data output time are similar. For example, if the initial time synchronization is not performed and the total exposure time is 15 seconds, the exposure time of the first line may be 1-10 seconds, the exposure time of the second line may be 2-11 seconds, the exposure time of the third line may be 3-12 seconds … … and the exposure time of the sixth line may be 6-15 seconds. The effective exposure period at this time is 6 th to 10 th seconds, and thus the light emission period of the light source can be set within 6 th to 10 th seconds. The total duration of the light source having a luminous intensity other than 0 may be equal to or shorter than 5 seconds.

The luminous time periods of the blue light source and the green light source in the light source set are in the effective exposure time period of the corresponding image acquisition device, so that different positions (such as different rows) on the image acquired by the image acquisition device are acquired under the same illumination condition, consistency of imaging conditions of the acquired image is ensured, and the effect of subsequent fusion splicing or splicing fusion is improved.

According to an embodiment of the invention, the illumination system comprises one or more light source sets, each light source set comprising at least one blue light source and at least one green light source, the one or more light source sets being in one-to-one correspondence with the one or more image acquisition devices, the method further comprising:

for each of the one or more image acquisition devices,

extracting a blue channel and a green channel from the same palm print image acquired by the image acquisition device to obtain a current blue channel image and a current green channel image;

respectively calculating the contrast and/or brightness of the current blue channel image and the current green channel image;

based on the contrast and/or brightness of the current blue channel image and the contrast and/or brightness of the current green channel image, determining the adjusted blue light luminous intensity and the adjusted green light luminous intensity of the light source set corresponding to the image acquisition device, wherein the adjusted blue light luminous intensity and the adjusted green light luminous intensity enable the contrast and/or brightness of the subsequent blue channel image acquired by the image acquisition device under the adjusted blue light luminous intensity and the contrast and/or brightness of the subsequent green channel image acquired by the image acquisition device under the adjusted green light luminous intensity to be consistent;

Blue light sources in a light source set corresponding to the image acquisition device are controlled to emit blue light to a palm print acquisition area according to the adjustment of the luminous intensity of the blue light;

and controlling the green light sources in the light source set corresponding to the image acquisition device to emit green light to the palm print acquisition area according to the adjustment of the green light luminous intensity.

The present embodiment is described below with three image capturing devices and three light source sets as an example. For example, images of a blue channel and a green channel in the images currently acquired by the three image acquisition devices may be extracted in real time, and the contrast and/or brightness of the blue channel image and the green channel image corresponding to each of the three image acquisition devices may be calculated. For example, the respective corresponding luminance values may be obtained by calculating a histogram of the blue channel image and a histogram of the green channel image. Subsequently, the adjusted blue light luminous intensity corresponding to each of the three light source sets corresponding to the three image acquisition devices one by one can be calculated according to the contrast and/or brightness of the three blue channel images corresponding to the three image acquisition devices one by one. And, the adjustment green light luminous intensity corresponding to each of the three light source sets corresponding to the three image acquisition devices one by one can be calculated according to the contrast and/or brightness of the three green channel images corresponding to the three image acquisition devices one by one. Then, at the next light emission, each of the three light source sets is controlled to emit light in accordance with the above-calculated adjusted blue light emission intensity and the adjusted green light emission intensity corresponding to itself.

The above embodiments can independently adjust the light source intensity of a single channel. By independently adjusting the blue-green light sources, the light sources with the same color at different acquisition positions can have more consistent contrast and/or brightness, so that the images at different acquisition positions can be conveniently spliced together to obtain better splicing effect. In addition, through the scheme of independently adjusting the light source intensity of single channel, can adjust the luminous intensity of current blue green light source in order to adapt to the situation of different skin better based on the reaction condition of skin to light to can further adapt to more crowds.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided by the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described device embodiments are merely illustrative, e.g., the division of the elements is merely a logical functional division, and there may be additional divisions when actually implemented, e.g., multiple elements or components may be combined or integrated into another device, or some features may be omitted or not performed.

Similarly, it should be appreciated that in order to streamline the invention and aid in understanding one or more of the various inventive aspects, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of the invention. However, the method of the present invention should not be construed as reflecting the following intent: i.e., the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

It will be understood by those skilled in the art that all of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or units of any method or apparatus so disclosed, may be combined in any combination, except combinations where the features are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Various component embodiments of the invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that some or all of the functions of some of the modules in a fingerprint acquisition system according to embodiments of the present invention may be implemented in practice using a microprocessor or Digital Signal Processor (DSP). The present invention can also be implemented as an apparatus program (e.g., a computer program and a computer program product) for performing a portion or all of the methods described herein. Such a program embodying the present invention may be stored on a computer readable medium, or may have the form of one or more signals. Such signals may be downloaded from an internet website, provided on a carrier signal, or provided in any other form.

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 may 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 use of the words first, second, third, etc. do not denote any order. These words may be interpreted as names.

In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships in normal use, are merely used for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements being referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. The term "connected" may mean directly connected or indirectly connected via other devices or elements.

The foregoing description is merely illustrative of specific embodiments of the present invention and the scope of the present invention is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the scope of the present invention. The protection scope of the invention is subject to the protection scope of the claims.

Claims (23)

1. A hand print 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 palm print acquisition zone for placing part or all of a user's hand;

one or more image acquisition devices for acquiring images of the palm print acquisition area while the illumination system is emitting light to the palm print acquisition area to obtain palm print images;

and the processing device is used for processing the hand vein 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 palm print acquisition system further comprises:

a structured light projector for emitting structured light toward the palm print collection zone;

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

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

4. The system of any of claims 1-3, 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 palm print acquisition area facing the one or more image acquisition devices, the optical axis of the second image acquisition device and the optical axis of the first image acquisition device form a first preset included angle, and the optical axis of the third image acquisition device and the optical axis of the first image acquisition device form a second preset included angle.

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

6. The system of any of claims 1-5, wherein the palm print acquisition system further comprises a shade member, the shade member and at least a portion of the light sources in the illumination system being positioned on opposite sides of the palm print acquisition zone, respectively.

7. The system of any one of claims 1 to 6, wherein the fingerprint acquisition system further comprises a spacing member defining the fingerprint acquisition area,

an inlet is arranged at the proximal end of the limiting component so as to allow part or all of the hand of the user to extend into the palm print collecting area through the inlet;

the distal end of the limiting member is provided with a stopper portion located at a predetermined position of the palm print collecting area along the extending direction so as to limit a portion or all of the user's hand from extending into the position within the palm print collecting area.

8. The system of claim 7, wherein,

the limiting part further comprises a connecting part for connecting the inlet with the stop part, and the upper surface of the connecting part is attached to the lower surface of the shading part.

9. The system of any of claims 1-8, wherein the illumination system comprises one or more light source sets, each light source set comprising at least one blue light source and at least one green light source, the one or more light source sets being in one-to-one correspondence with the one or more image capture devices.

10. The system of claims 1-9, wherein the illumination system comprises at least one light source pair, each light source pair comprising one blue light source and one green light source, the distance between the blue light source and the green light source within the same light source pair being less than a preset distance threshold.

11. A method of fingerprint acquisition implemented with the fingerprint acquisition system of any one of claims 1 to 10, comprising:

acquiring images of the hand print acquisition area by the one or more image acquisition devices when the blue light source group emits light in a blue light emission scheme and the green light source group emits light in a green light emission scheme, so as to acquire hand print images acquired by the one or more image acquisition devices, wherein at least one hand print image is acquired under the condition that a blue light source with luminous intensity which is not 0 exists in the blue light source group, and at least one hand print image is acquired under the condition that a green light source with luminous intensity which is not 0 exists in the green light source group;

the blue light source group comprises one or more blue light sources, the green light source group comprises one or more green light sources, a blue light emitting scheme is used for representing the light emitting intensity of each blue light source, and a green light emitting scheme is used for representing the light emitting intensity of each green light source; at the time of collection, the luminous intensity of at least one light source is not 0.

12. The method of claim 11, wherein the acquiring comprises acquiring a plurality of times, at least two of the plurality of acquisitions differing in a corresponding blue light emission scheme, and/or at least two of the plurality of acquisitions differing in a corresponding green light emission scheme.

13. The method of claim 11, wherein the acquiring comprises a plurality of acquisitions, each of the plurality of acquisitions differing in a corresponding blue light emission scheme, and/or each of the plurality of acquisitions differing in a corresponding green light emission scheme.

14. The method of claim 12 or 13, wherein at least two acquisitions of the corresponding blue or green lighting scheme are identical.

15. The method of any of claims 12-14, wherein there are no two acquisitions corresponding to the same blue light emission scheme and the same green light emission scheme.

16. The method of claim 11, wherein the capturing, by the one or more image capturing devices, the image of the palm print capture area while the blue light source set emits light in a blue light emission scheme and the green light source set emits light in a green light emission scheme comprises:

at a first moment, when the blue light source group emits light according to a first blue light emitting scheme and the green light source group emits light according to a first green light emitting scheme, acquiring images of the palm print acquisition area through at least part of the image acquisition devices in the one or more image acquisition devices;

at a second moment, when the blue light source group emits light according to a second blue light emitting scheme and the green light source group emits light according to a second green light emitting scheme, the image of the palm print collecting area is collected by at least part of the image collecting devices in the one or more image collecting devices,

Wherein the first blue light emitting scheme and the second blue light emitting scheme are selected from a set of blue light emitting schemes, and the first green light emitting scheme and the second green light emitting scheme are selected from a set of green light emitting schemes; the blue light emitting scheme set comprises w blue light emitting schemesW has a maximum value of 2 ^k1 At 2 ^k1 In the blue light emitting scheme, the light emitting intensity of any blue light source is divided into 0 and non-0 steps; the green light emitting scheme set comprises p green light emitting schemes, wherein the maximum value of p is 2 ^k2 At 2 ^k2 In the green light emitting scheme, the light emitting intensity of any green light source is divided into 0 and non-0 steps; k1 is the total number of blue light sources in the lighting system and k2 is the total number of green light sources in the lighting system; w is an integer greater than or equal to 2 and/or p is an integer greater than or equal to 2; the first blue light emitting scheme is different from the second blue light emitting scheme, and/or the first green light emitting scheme is different from the second green light emitting scheme.

17. The method of claim 16, wherein the first blue light emitting scheme is the same as the second blue light emitting scheme or the first green light emitting scheme is the same as the second green light emitting scheme.

18. The method of claim 16 or 17, wherein the capturing, by the one or more image capturing devices, the image of the palm print capture area while the blue light source set emits light in a blue light emission scheme and the green light source set emits light in a green light emission scheme further comprises:

at a third moment, when the blue light source group emits light according to a third blue light emitting scheme and the green light source group emits light according to a third green light emitting scheme, the image of the palm print collecting area is collected by at least part of the image collecting devices in the one or more image collecting devices,

wherein the third blue light emitting scheme is selected from the set of blue light emitting schemes and the third green light emitting scheme is selected from the set of green light emitting schemes;

the third blue light emitting scheme is different from at least one of the first blue light emitting scheme and the second blue light emitting scheme; and/or, the third green light emitting scheme is different from at least one of the first green light emitting scheme and the second green light emitting scheme;

there are no two acquisitions corresponding to the same blue light emission scheme and the same green light emission scheme.

19. The method of claim 18, wherein the lighting scheme satisfies both the first condition and the second condition;

The first condition includes: the first blue light emitting scheme is the same as the second blue light emitting scheme, or the first green light emitting scheme is the same as the second green light emitting scheme;

the second condition includes: the third blue light emitting scheme is the same as the first blue light emitting scheme, or the third blue light emitting scheme is the same as the second blue light emitting scheme, or the third green light emitting scheme is the same as the first green light emitting scheme, or the third green light emitting scheme is the same as the second green light emitting scheme.

20. The method of any of claims 11-19, wherein a number of image acquisition devices of the one or more image acquisition devices is greater than 1, using all image acquisition devices per acquisition.

21. The method of any of claims 11-19, wherein a number of image capture devices in the one or more image capture devices is greater than 1, the image capture devices used for at least two of the multiple acquisitions not being identical.

22. The method of claim 21, wherein the one or more image capture devices comprise a first image capture device, a second image capture device, and a third image capture device, wherein,

The optical axis of the first image acquisition device is perpendicular to the plane of the palm print acquisition area facing the one or more image acquisition devices, the optical axis of the second image acquisition device forms 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 forms a second preset included angle with the optical axis of the first image acquisition device; the illumination system comprises one or more light source sets, each light source set comprises at least one blue light source and at least one green light source, and the one or more light source sets are in one-to-one correspondence with the one or more image acquisition devices;

when the blue light source group emits light according to a blue light emitting scheme and the green light source group emits light according to a green light emitting scheme, the capturing the image of the palm print capturing area by the one or more image capturing devices includes:

at a first moment, when the blue light source group emits light according to a first blue light emitting scheme and the green light source group emits light according to a first green light emitting scheme, acquiring an image of the palm print acquisition area through the first group of image acquisition devices;

at a second moment, when the blue light source group emits light according to a second blue light emitting scheme and the green light source group emits light according to a second green light emitting scheme, the second group of image acquisition devices acquire the image of the palm print acquisition area,

Wherein the first group of image acquisition devices are one of the first image acquisition devices and the angle image acquisition devices, and the second group of image acquisition devices are the other one of the first image acquisition devices and the angle image acquisition devices; the angle image acquisition device comprises the second image acquisition device and the third image acquisition device, and the first blue light emission scheme is that the blue light source corresponding to the image acquisition device for acquisition at the first moment in the blue light source group is not 0 in light emission intensity; the first green light emitting scheme is that the light emitting intensity of the green light sources corresponding to the image acquisition device for acquiring at the first moment in the green light source group is not 0; the second blue light emitting scheme is that the light emitting intensity of the blue light source corresponding to the image acquisition device for acquiring at the second moment in the blue light source group is not 0; the second green light emitting scheme is that only the green light source light emitting intensity corresponding to the image acquisition device for acquiring at the second moment in the green light source group is not 0.

23. The method of any of claims 11 to 22, wherein the illumination system comprises one or more light source sets, each light source set comprising at least one blue light source and at least one green light source, the one or more light source sets being in one-to-one correspondence with the one or more image acquisition devices, the method further comprising:

For each of the one or more image acquisition devices,

extracting a blue channel and a green channel from the same palm print image acquired by the image acquisition device to obtain a current blue channel image and a current green channel image;

respectively calculating the contrast and/or brightness of each of the current blue channel image and the current green channel image;

determining the adjusted blue light luminous intensity and the adjusted green light luminous intensity of a light source set corresponding to the image acquisition device based on the contrast and/or brightness of the current blue channel image and the contrast and/or brightness of the current green channel image, wherein the adjusted blue light luminous intensity and the adjusted green light luminous intensity enable the contrast and/or brightness of a subsequent blue channel image acquired by the image acquisition device under the adjusted blue light luminous intensity and the contrast and/or brightness of a subsequent green channel image acquired by the image acquisition device under the adjusted green light luminous intensity to be consistent;

blue light sources in a light source set corresponding to the image acquisition device are controlled to emit blue light to the palm print acquisition area according to the adjusted blue light luminous intensity;

and controlling green light sources in the light source set corresponding to the image acquisition device to emit green light to the palm print acquisition area according to the adjusted green light luminous intensity.