CN-115862107-B - Device and method for collecting iris images of human face

CN115862107BCN 115862107 BCN115862107 BCN 115862107BCN-115862107-B

Abstract

The invention provides a device for collecting iris images of human faces, which comprises a human face optical imaging unit, a human eye detection unit, an optical mapping unit, a local area configuration unit, an iris optical imaging unit, an iris image AF automatic focusing unit and an image collecting and processing unit, wherein the optical mapping unit is used for realizing the transformation of the optical geometrical mapping relation of object images corresponding to the human face optical imaging unit according to the position of a human face binocular central pixel corresponding to the human eye detection unit, and the local area configuration unit is used for realizing the synchronous dynamic configuration of the iris image local area with fixed pixel resolution corresponding to the iris optical imaging unit according to the optical geometrical mapping relation corresponding to the optical mapping unit.

Inventors

NI WEIMIN
WU DONGYAN

Assignees

苏州思源科安信息技术有限公司

Dates

Publication Date: 20260508
Application Date: 20221206
Priority Date: 20211209

Claims (12)

1. A device for face iris image acquisition, comprising: The device comprises a face optical imaging unit, an iris optical imaging unit, an optical imaging association unit and an image acquisition processing unit; The image acquisition processing unit is respectively connected with the face optical imaging unit, the iris optical imaging unit and the optical imaging association unit and controls the face optical imaging unit, the iris optical imaging unit and the optical imaging association unit; the face optical imaging unit outputs a global area face image; the optical imaging association unit is used for establishing a synchronous association relation of the output global-local area image between the preset face optical imaging unit and the iris optical imaging unit; The iris optical imaging unit outputs a corresponding partial region iris image according to the synchronous association relation; The imaging field of view of the face optical imaging unit is larger than or equal to that of the iris optical imaging unit; The optical imaging association unit comprises a human eye detection unit, an optical mapping unit and a local area configuration unit; The face optical imaging unit is used for acquiring a face image of the global area; The human eye detection unit is used for detecting the positions of the center pixels of the two eyes of the human face from the global area human face image acquired by the human face optical imaging unit; the optical mapping unit is used for converting the optical geometrical mapping relation of the object image corresponding to the optical imaging unit of the human face according to the positions of the central pixels of the two eyes of the human face detected by the human eye detection unit; The local area configuration unit is used for synchronously and dynamically configuring the iris image local area with fixed pixel resolution corresponding to the iris optical imaging unit according to the object image optical geometric mapping relation obtained by the transformation of the optical mapping unit; The iris optical imaging unit is used for acquiring iris images of local areas according to the iris image local areas with fixed pixel resolution synchronized by the local area configuration unit.
2. The device for face iris image acquisition according to claim 1, wherein when the optical mapping unit converts the face optical imaging unit according to the face binocular central pixel position of the human eye detection unit in response to the object image optical geometry mapping relationship of the iris optical imaging unit, the method for calculating the conversion factor OMTF is as follows: OMTF=Fi*PSe/(Fe*PSi) =(PXi-cPXi/2)/(PXe-cPXe/2) =(PYi-cPYi/2)/(PYe-cPYe/2) Wherein OMTF is a conversion factor with an inherent object-image optical geometric mapping relation, fi is an imaging optical focal length of an iris optical imaging unit, PSe is unit pixel resolution of a face optical imaging unit, fe is an imaging optical focal length of the face optical imaging unit, PSi is unit pixel resolution of the iris optical imaging unit, (PXI, PYI) is an XY coordinate of a center pixel position of two eyes of an image side of the iris optical imaging unit, (cPXI, cPYI) is an XY pixel resolution of an image side of the iris optical imaging unit, (PXe, pee) is an XY coordinate of a center pixel position of two eyes of an image side of the face optical imaging unit, and (cPXe, cPee) is an XY pixel resolution of an image side of the face optical imaging unit.
3. The apparatus for face iris image acquisition according to claim 1, wherein the dynamic synchronization update frequency of the execution association state between the optical mapping unit and the local area configuration unit is controlled by defining the iris image local area.
4. The apparatus for face iris image collection according to claim 1, wherein the iris optical imaging unit collects a partial area iris image which is an image within an area surrounded by a pixel range (PXroi, PYroi) centered on a pixel position (PXi, PYi) coordinate, which is collected when the partial area iris image is collected according to an iris image partial area synchronized by the partial area configuration unit; PXRoi, PXRoi is the XY pixel range of the iris image local area; cPXi/16<=PXroi<=cPXi/2,cPYi/16<=PYroi<=cPYi/2 ROI=RECT(left,top,right,bottom) =RECT(PXi-PXroi/2,PYi-PYroi/2,PXi+PXroi/2,PYi+PYroi/2); or roi=rect (left, top, width, height) =RECT(PXi-PXroi/2,PYi-PYroi/2,PXroi,PYroi)。
5. The apparatus for face iris image acquisition as claimed in claim 4, wherein, when the partial area iris image is acquired according to the pixel positions (PXi, PYi) and the pixel ranges (PXroi, PYroi), the partial array image output (x_add_start, y_add_start, y_add_end) or the corresponding digital OFFSET partial array image output (x_drop_offset, y_drop_offset, x_drop_width, y_drop_head) is obtained by using a physical analog partial array image output (x_add_start, y_add_start, y_add_end) corresponding to the imaging pixel array path of the iris optical imaging unit; Wherein: X_ADD_START=left=PXi-PXroi/2, Y_ADD_START=top=PYi-PYroi/2, X_ADD_END=right=PXi+PXroi/2, Y_ADD_END=bottom=PYi+PYroi/2; Or (b) X_CROP_OFFSET=left=PXi-PXroi/2, Y_CROP_OFFSET=top=PYi-PYroi/2, X_CROP_WIDTH=width=PXroi, Y_CROP_HEIGHT=height=PYroi。
6. The apparatus for face iris image collection according to claim 1, further comprising an iris image AF autofocus unit, wherein the image collection processing unit is connected to the iris image AF autofocus unit and controls the iris image AF autofocus unit; The iris image AF automatic focusing unit is used for automatically focusing the partial area iris image according to the partial area iris image corresponding to the iris optical imaging unit to obtain the focused partial area iris image.
7. The apparatus for face iris image acquisition of claim 6, wherein the iris image AF autofocus unit is controlled using imaging lens driving parameters for performing an iris optical imaging unit.
8. The apparatus for face iris image collection according to claim 7, wherein the parameter control by the iris image AF autofocus unit is achieved by adjusting an imaging optical image distance or adjusting an imaging optical focal length/diopter power depending on an imaging lens driving type.
9. The apparatus for face iris image acquisition according to claim 7, wherein the control of the imaging lens driving parameters of the iris optical imaging unit includes a STEP number 2x k+1 and a STEP size STEP parameter, K being a STEP number; realizing unidirectional continuous automatic focusing in a preset focusing range fr= (2 x k+1) x STEP; Wherein: STEP=2*FNO*SOC; FNO is aperture parameter of the iris optical imaging unit; The SOC is a physical light spot minimum resolution parameter of the iris optical imaging unit.
10. The apparatus for face iris image acquisition according to claim 9, wherein the imaging lens driving parameter control method of the iris optical imaging unit comprises: Step S1, calculating PD, wherein PD is a phase difference corresponding to a partial area of an iris image; step S2, calculating a corresponding focusing position relative distance FP according to the phase difference obtained in the step S1, wherein a calculation formula is as follows: FP=PD*CC; wherein CC is a conversion coefficient convert coefficient of the phase difference and the corresponding focusing position relative distance FP, namely the defocus rate, and the defocus rate is realized through fitting an actual corresponding linear or nonlinear relation; STEP S3, driving a PDAF type driver to execute imaging lens driving parameters of the iris optical imaging unit according to the focusing position relative distance FP obtained in the STEP S2, and driving the corresponding focusing position relative distance FP, namely directly driving STEP' S by K stepping positions; STEP S4, iterating STEPs S1-S3, ending at PD < = EP, EP = STEP/CC, EP being a predetermined phase difference focus error, i.e. ending at a single STEP length, K < = 1.
11. The method for collecting the iris image of the human face is characterized by comprising a human face optical imaging unit, a human eye detection unit, an optical mapping unit, a local area configuration unit, an iris optical imaging unit and an image collecting and processing unit, wherein the image collecting and processing unit is respectively connected with the human face optical imaging unit, the human eye detection unit, the optical mapping unit, the local area configuration unit and the iris optical imaging unit and controls the human face optical imaging unit, the human eye detection unit, the optical mapping unit, the local area configuration unit and the iris optical imaging unit; The method comprises the following specific steps: Step one, an image acquisition processing unit controls a face optical imaging unit to acquire a global area face image; step two, the image acquisition processing unit controls the human eye detection unit to detect the positions of the center pixels of the two eyes of the human face from the human face image of the global area acquired in the step one; step three, the image acquisition processing unit controls the optical mapping unit to convert the optical geometrical mapping relation of the object image corresponding to the optical imaging unit of the human face in response to the optical imaging unit of the iris according to the center pixel position of the eyes of the human face detected in the step two; Step four, the image acquisition processing unit synchronously and dynamically configures iris image local areas with fixed pixel resolution corresponding to the iris optical imaging unit according to the object image optical geometric mapping relation obtained by the transformation in the step three; and fifthly, controlling the iris optical imaging unit to acquire iris images of the local areas by the image acquisition processing unit according to the iris image local areas obtained in the synchronous dynamic configuration in the step four.
12. The method for facial iris image capture as in claim 11, further comprising an iris image AF autofocus unit, the image capture processing unit being coupled to and controlling the iris image AF autofocus unit; step six is also arranged after the step five; and step six, controlling the automatic focusing of the local area iris image by the image acquisition processing unit according to the local area iris image acquired in the step five, and obtaining the focused local area iris image.

Description

Device and method for collecting iris images of human face Technical Field The invention relates to the technical field of optical image acquisition, in particular to a device and a method for acquiring a human face iris image. Background The current solution is mainly to use 2-axis rotation iris optical imaging system, or high pixel resolution iris optical imaging system, facing the increasingly long-distance wide-angle field of view iris image acquisition. The invention application number 202011131179 discloses an iris image acquisition device and method of a multi-target crowd, the device comprises a base, a vertical motor module, a horizontal motor module, a reflecting mirror, an objective table module, a motion limiting piece and a control system, wherein the base supports and fixes an integral two-dimensional turntable, the vertical motor module comprises a vertical motor and a vertical motion adapter plate, the horizontal motor module comprises a horizontal motor, a supporting plate, a horizontal motion adapter plate and a rolling bearing, the reflecting mirror is fixed on the objective table module, the objective table module comprises an object carrying plate, an object carrying support and a fixing piece and is fixed with the horizontal motor module, the motion limiting pieces are arranged at different positions, the control system comprises a driver, a PLC (programmable logic controller) and a PC (personal computer) control card and control turntable motion, and an iris camera is vertically arranged. The device can effectively increase the iris recognition visual field, automatically adapt to different height targets in different directions and distances, and has high speed and strong robustness. The application number 202110588620 discloses an image information processing method and system for specific objects, wherein the system comprises a first module for collecting image or video data; the facial feature analysis device comprises a first module for determining facial feature range data from the image and video data acquired by the first module, a third module for extracting feature data from the facial feature range data, comprising a first unit for determining the detection point position of facial features from the facial feature range data and extracting feature data from the detection point position, a second unit for determining the detection area position of facial skin features from the facial feature range data and extracting feature data from the detection area position, a third unit for determining the detection area position of facial iris features from the facial feature range data and extracting feature data from the detection point position, a fourth module for processing and analyzing the facial feature data, the facial skin feature data and the facial iris feature data, comprising a fourth unit for comparing the facial feature data with pre-stored facial feature data and obtaining a result, a fifth unit for comparing the facial skin feature data with the pre-stored facial skin feature data and obtaining a comparison result, a fifth module for comparing the facial feature data with the facial feature data and obtaining a comparison result, and comparing the facial feature data with the facial iris feature data and the facial iris feature data, the face recognition judging unit comprises a seventh unit, an eighth unit and a sixth module, wherein the seventh unit is used for respectively carrying out normalization operation on the comparison and analysis result of the facial feature data, the comparison and analysis result of the facial skin feature data and the comparison and analysis result of the facial iris feature data, the eighth unit is used for carrying out comprehensive processing on the normalization result of the comparison and analysis result of the facial feature data, the normalization result of the comparison and analysis result of the facial skin feature data and the normalization result of the comparison and analysis result of the facial iris feature data to obtain a face recognition judging result, and the sixth module is used for carrying out response processing according to the comprehensive judgment result of the face recognition. As in the two patent applications mentioned above, in the prior art, in view of the trend towards high pixel resolution in the future, such as above 64M pixel resolution. In the prior art, when video is acquired and human face iris processing is carried out, human face images and iris images are acquired respectively, and when the human face state changes, the human face images and the iris images are acquired respectively, so that the image data is huge. On the basis, image data acquisition and transmission are brought along with challenges of transmission bandwidth, the frame rate requirements of real-time image processing cannot be met obviously at the resolution of 64M pixels, the lower the frame rate is, the image acquisition