WO2021098132A1 - 一种远距离大视场虹膜光学成像的装置及方法 - Google Patents

一种远距离大视场虹膜光学成像的装置及方法 Download PDF

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WO2021098132A1
WO2021098132A1 PCT/CN2020/084772 CN2020084772W WO2021098132A1 WO 2021098132 A1 WO2021098132 A1 WO 2021098132A1 CN 2020084772 W CN2020084772 W CN 2020084772W WO 2021098132 A1 WO2021098132 A1 WO 2021098132A1
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iris
optical imaging
image
imaging
light source
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PCT/CN2020/084772
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French (fr)
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倪蔚民
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苏州思源科安信息技术有限公司
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    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T1/00General purpose image data processing
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06VIMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V10/00Arrangements for image or video recognition or understanding
    • G06V10/10Image acquisition

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  • the invention relates to the technical field of optical imaging, in particular to a device and method for long-distance large-field-of-view iris optical imaging.
  • Known iris imaging devices have the following shortcomings.
  • the imaging time to obtain images in a long working distance and large working field of view scene exceeds 1-3s, and the user cannot remain consistent and relatively still for such a long time, due to the image iris diameter Requires a large magnification requirement of >200pixel, resulting in a very slight movement that can cause the field of view of the iris imaging system to be re-adjusted, zoom focus, and illumination.
  • traditional distance measurement includes software mapping iris diameter or binocular distance, because the error is too large due to the variation in the population that is greater than 20%, and the accurate working distance information cannot be provided, which directly affects the overall performance.
  • physical measurements such as infrared, ultrasound, and tof.
  • the distance is too large to provide accurate working distance information under the scenes of long working distance and large working field of view.
  • the known technology has image quality such as depth of field, image brightness, image relative illuminance, illuminating light source radiation intensity, and iris irradiance of the eye. In the scene of long working distance and large working field of view, the consistency cannot be guaranteed, and even the difference is several times.
  • the traditional lighting source is adjusted with the inverse square of the working distance, and the radiation intensity of the non-constant light source (such as the range of 2 to 3 times the working distance, The angle of view changes by 2 to 3 times, and the radiation intensity changes by 4 to 9 times), resulting in the inability to meet the requirements of constant field of view and radiation illuminance in a large range at the same time.
  • the traditional improved imaging field of view uses a mechanical pan/tilt structure, which leads to complex control, low positioning error accuracy, low stability and reliability, serious problems in power consumption, volume and noise life, and time-consuming imaging after waiting for the adjustment of the pan/tilt position Very severe imaging speed is very slow.
  • One aspect of the present invention is to provide a device for optical imaging of a long-distance iris with a large field of view, the device comprising:
  • Iris optical tracking system iris zoom focusing optical imaging system, LED illumination light source radiation system, image display feedback system, image processing and drive control system;
  • the iris optical tracking system includes a 3D depth imaging unit for performing 3D physical space point coordinate acquisition;
  • the iris zoom focusing optical imaging system includes an optical zoom focusing lens group and an ultra-high-resolution image imaging sensor, which is used to perform focal length and/or focus position adjustment of iris imaging according to 3D physical space point coordinates, and ultra-high-resolution image imaging Sensor physical imaging;
  • the LED illumination light source radiation system includes a solid angle of radiation intensity and/or a direction angle of radiation intensity, which is used to perform the matching relationship between the field of view angles of the iris zoom focusing optical imaging system corresponding to different working distances according to the 3D physical space point coordinates
  • the combination control ;
  • the image display feedback system includes a display screen for real-time display of current images and/or status information
  • the image processing and drive control system is connected to the iris optical tracking system, the iris zoom focusing optical imaging system, the LED illumination light source radiation system, and the image display feedback system, and realizes the drive and feedback control between the system units.
  • the imaging field angle of the 3D depth imaging unit is greater than or equal to the imaging field angle of the iris zoom focusing optical imaging system.
  • the 3D depth imaging unit includes 3D TOF depth imaging or structured light depth imaging, or binocular stereo vision imaging.
  • the ultra-high resolution image imaging sensor has a resolution of at least 8K.
  • D is the optical center of the LED illumination light source radiation system and the optical center of the iris zoom focusing optical imaging system Distance
  • Z is the working distance of the iris zoom focusing optical imaging system.
  • arctan((PXiris 2 +PYiris 2 ) 1/2 /2*PSiris/((1+ ⁇ )*EFLiris))
  • Arctan((PXiris 2 +PYiris 2 ) 1/2 /2*PSiris/( ⁇ *Z)), ⁇ is the half field angle of the iris zoom focusing optical imaging system,
  • PXiris is the pixel resolution in the X horizontal direction of the iris zoom focusing optical imaging system
  • PYiris is the Y vertical pixel resolution of the iris zoom focusing optical imaging system
  • EFLiris is the focal length position
  • PR*PSiris
  • PR is the image-side resolution of the physical diameter of the iris
  • PSiris is the pixel unit resolution of the ultra-high resolution image imaging sensor of the iris zoom focusing optical imaging system
  • Z is the working distance of the iris zoom focusing optical imaging system.
  • the LED illumination light source radiation system and the iris zoom focusing optical imaging system are configured as:
  • the combined imaging mode of global pixel exposure (integration) and illumination radiation in the synchronization pulse external trigger or the synchronization pulse internal trigger mode in the combination of the filter in which:
  • PR is the image resolution of the physical diameter of the iris
  • m is the pixel scale of the motion blur image that is predetermined to be controlled, the unit is pixel;
  • the synchronization pulse exposure (integration) frequency and the synchronization pulse illumination radiation frequency Fpulse of the combined imaging mode, the synchronization pulse illumination radiation frequency Fpulse [10, 30] Hz,
  • the LED illuminating light source radiation system generates synchronous pulsed illuminating radiation on the surface of the iris.
  • Eiris ( ⁇ ) is the irradiance on the surface of the iris.
  • Another aspect of the present invention is to provide a method for optical imaging of a long-distance large field of view iris, the method comprising:
  • the image processing and drive control system implements the drive and feedback control process between the iris optical tracking system, the iris zoom focusing optical imaging system, the LED illumination light source radiation system, and the image display feedback system:
  • the 3D depth imaging unit of the iris optical tracking system obtains the 3D coordinates of the key points of the iris, and converts the relative coordinates to 3D physical space points to achieve real-time synchronous iris optical imaging tracking;
  • the image display feedback system displays the current image and/or status information in real time
  • the image display feedback system realizes real-time synchronous display that the current image is an infrared image imaged by a 3D depth imaging unit, an RGB visible light unit imaging image or an iris zoom focusing optical imaging image.
  • the feedback control iris imaging tracking system includes:
  • EFLface [(PXface 2 +PYface 2 ) 1/2 *PSface/2]/tan(FOVface/2)
  • PXface is the X horizontal pixel resolution of the 3D depth imaging unit
  • PYface is the Y vertical pixel resolution of the 3D depth imaging unit
  • PSface is the pixel unit resolution of the 3D depth imaging unit
  • EFLface is the effective imaging focal length of the 3D depth imaging unit.
  • KPface(Xe,Ye,Ze) KPface(xe*z/EFLface,ye*z/EFLface,z).
  • Xoffset, Yoffset, Zoffset is the 3D physical position coordinate offset of the 3D depth imaging unit relative to the iris zoom focusing optical imaging system.
  • the feedback control of the iris zoom focusing optical imaging system includes:
  • PR*PSiris
  • PR is the image-side resolution of the physical diameter of the iris
  • Z is the working distance of the iris zoom focusing optical imaging system
  • SOC is the minimum physical spot resolution parameter of the iris zoom focusing optical imaging system.
  • the feedback control LED illumination light source radiation system includes:
  • the radiation direction angle of the LED illumination light source ⁇ arctan (D/Z),
  • D is the optical center of the LED illumination light source radiation system and the optical center of the iris zoom focusing optical imaging system Distance
  • Z is the working distance of the iris zoom focusing optical imaging system
  • arctan((PXiris 2 +PYiris 2 ) 1/2 /2*PSiris/((1+ ⁇ )*EFLiris))
  • Arctan((PXiris 2 +PYiris 2 ) 1/2 /2*PSiris/( ⁇ *Z)), ⁇ is the half field angle of the iris zoom focusing optical imaging system,
  • PXiris is the pixel resolution in the X horizontal direction of the iris zoom focusing optical imaging system
  • PYiris is the Y vertical pixel resolution of the iris zoom focusing optical imaging system
  • EFLiris is the focal length position
  • PR*PSiris
  • PR is the image-side resolution of the physical diameter of the iris
  • PSiris is the pixel unit resolution of the ultra-high resolution image imaging sensor of the iris zoom focusing optical imaging system
  • Z is the working distance of the iris zoom focusing optical imaging system.
  • the device and method for long-distance and large-field-of-view iris optical imaging provided by the present invention simultaneously realize constant field of view and radiation illuminance in a large range, and has the following advantages:
  • Constant magnification is the same iris diameter of the imaged image.
  • the moving speed up to 1m/s is not affected by motion blur, and resists the interference of various ambient light>10,000lux noise conditions.
  • Fig. 1 schematically shows a schematic diagram of a device for optical imaging of a long-distance large field of view iris in an embodiment of the present invention.
  • the field of view of the 3D depth imaging unit is the predetermined working field of view FOVface
  • the zoom focus imaging lens group of the 120 iris zoom focus optical imaging system
  • the LED illuminating light source radiates the left and right side of the LED illuminating light source of the system
  • the LED illuminating light source radiates the left and right side LED illuminating light source of the system
  • the solid angle of the radiation intensity of the left/right illuminating light source of the LED illumination light source radiation system is matched with the far end working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system Field of view FOViris-far,
  • the solid angle of the left/right illuminating light source radiation intensity of the LED illumination light source radiation system is matched with the near-end working radius/distance of the iris zoom focusing optical imaging system.
  • the left/right illuminating light source radiation intensity direction angle of the LED illumination light source radiation system is matched with the near-end working radius/distance Rnear/Znear of the iris zoom focusing optical imaging system
  • the left/right illuminating light source radiation intensity direction angle of the LED illumination light source radiation system matches the far end working radius/distance Rfar/Zfar of the iris zoom focusing optical imaging system
  • a long-distance large-field iris optical imaging device 100 includes: iris optics Tracking system, iris zoom focusing optical imaging system, LED illumination light source radiation system, image display feedback system 160, image processing and drive control system 150.
  • the iris optical tracking system includes a 3D depth imaging unit.
  • the 3D depth imaging unit can adopt 3D TOF depth imaging or structured light depth imaging (for example, 940nm infrared VCSEL light source 110, imaging lens and image imaging sensor 111), or binocular stereo vision imaging (LED illumination light source, 2 groups installed at a fixed distance)
  • the parameter symmetrical imaging lens and image imaging sensor provide depth image information.
  • the iris zoom focusing optical imaging system includes an optical zoom focusing lens group 120, an optical filter 121, and an ultra-high resolution image imaging sensor 122.
  • the LED illumination light source radiation system includes the combined control of the solid angle of the radiation intensity of the LED illumination light source and/or the direction and angle of the radiation intensity.
  • the image display feedback system 160 includes a display screen for real-time display of current images and/or status information.
  • the imaging field angle 115 of the 3D depth imaging unit is greater than or equal to the imaging field angle 124/125 of the iris zoom focusing optical imaging system.
  • the ultra-high resolution image imaging sensor 122 has a resolution of at least 8K.
  • the image processing and drive control system 150 is connected to the iris optical tracking system, the iris zoom focusing optical imaging system, the LED illumination light source radiation system, and the image display feedback system, and realizes the drive and feedback control between each system unit.
  • a method for long-distance large-field-of-view iris optical imaging includes: the image processing and drive control system executes the drive and feedback control process between each system unit as follows:
  • the 3D depth imaging unit obtains the 3D coordinates of the key points of the iris and converts the relative coordinates to 3D physical space points to realize real-time synchronous iris optical imaging tracking.
  • the image display feedback system displays the current image and/or status information in real time.
  • the image display feedback system realizes real-time synchronous display of the current image as the infrared brightness image imaged by the 3D depth imaging unit, the RGB visible light unit image or the iris zoom focus optical image.
  • the specific steps include:
  • EFLface [(PXface 2 +PYface 2 ) 1/2 *PSface/2]/tan(FOVface/2),
  • PXface is the X horizontal pixel resolution of the 3D depth imaging unit, pixel
  • PYface is the Y vertical pixel resolution of the 3D depth imaging unit, pixel
  • PSface is the pixel unit resolution of the 3D depth imaging unit, um/pixel;
  • EFLface is the effective imaging focal length of the 3D depth imaging unit, mm.
  • PXface 640pixels
  • PYface 480pixels
  • PSface 5.6um/pixel
  • EFLface 2.8mm.
  • a2 Define the 3D depth imaging unit to control and acquire the key points of the iris.
  • the well-known deep learning-based convolutional neural network CNN cascade model can reliably and accurately realize the functions of face region detection and eye positioning.
  • an independent or combined visible light RGB image imaging unit 114 is adopted, and the 3D depth imaging unit and the visible light RGB image imaging unit 114 are pre-calibrated and registered, and then the face area in the RGB image is further detected. And human eye positioning improves accuracy and reliability.
  • the RGB imaging unit can be used to detect the face when the device is in the standby state and trigger the system to enter the normal working state, thereby reducing the standby power consumption of the system.
  • the image formed by the visible light RGB image imaging unit is used in the image display feedback system to display the current image in real time.
  • this embodiment uses effective pixels in the local area of the center coordinates of the left and right eyes to filter interfering pixels, such as median filtering, or filtering of excessively high or low brightness in grayscale brightness images. Brightness pixels, or pixels whose depth is too far or too close in the image, etc.
  • KPface(xe,ye,z) KPface((xl+xr-PXface)/2*PSface,(yl+yr-PYface) )/2*PSface,z).
  • KPface (Xe, Ye, Ze) KPface (xe*z/EFLface, ye*z/EFLface, z).
  • Piris(X, Y, Z) (Xe-Xoffset, Xe-Yoffset, Ze-Zoffset),
  • (Xoffset, Yoffset, Zoffset) is the 3D physical position coordinate offset of the 3D depth imaging unit relative to the iris zoom focusing optical imaging system.
  • Perform synchronous control of the zoom and focus parameters of the iris zoom and focus optical imaging system including:
  • R is a predetermined working radius, including a predetermined proximal working radius Rnear116, a predetermined distal working radius Rfar118,
  • the predetermined working distance Z includes a predetermined near-end working distance Znear117 and a predetermined far-end working distance Zfar119.
  • the optical zoom operation can be performed after the Z interval is changed to a certain predetermined range. If you keep the same focal length relative to the range of 5-10cm, this design is reasonable, and the iris diameter itself also varies from person to person.
  • the iris zoom focusing optical imaging system Due to the error of the depth information, the iris zoom focusing optical imaging system has a precision mechanical error in the actual manufacturing process, individual deviations, etc., resulting in a 2k+1 times step length control position, the step length is ⁇ *DOF, generally 3-5 steps
  • the range is completely at the predetermined image-side focus position, ensuring that the focus position is within the object depth of field range of +-DOF/2 (equivalent, within the image-side depth of field range of +- ⁇ *DOF/2), and at the same time such a small number of control steps The number can be guaranteed to be completed in 0.1s.
  • the above-mentioned design of the present invention guarantees a constant depth of field range, and at the same time realizes that the focus position is within the depth of field range of the image plane.
  • Ideal aspheric optical glass/plastic hybrid 2 liquid lens liquid lenses independently control the focal length EFLiris and focus FOCUS respectively.
  • the above design requires both focal length and focus position to be converted to the correspondingly designed imaging optical system.
  • the diopter of the 2 liquid lenses is the unit specification Compared with the complex cam curve control driven by traditional stepping motors, the liquid lens has a diopter and voltage/current corresponding linear response optical property relationship, which can greatly simplify the drive control process, and this design can greatly reduce the overall imaging The number of system components (12-16 pieces in 3-4 groups).
  • the current liquid lens has a limited clear aperture, typically 6-10mm, and a limited diopter range -10 to +20 diopters.
  • the wavefront error increases to ⁇ /10 at large diopters, but It is suitable for iris zoom focusing optical imaging system due to the requirement of depth of field on FNO value and long focal length application.
  • Optical designers can use the characteristics of liquid lens to optimize the design of the optical path. For example, select the appropriate exit pupil in the optical path and design the FNO to solve the clear aperture.
  • the initial design of the zoom part of the optical system is to set the zoom liquid lens to work at 0 diopter optical power.
  • the far end working distance corresponds to the maximum focal length
  • the initial design of the focusing part of the optical system is to set the focusing liquid lens to work at the image plane position corresponding to the far end working distance when the focusing liquid lens is set at 0 diopter optical power.
  • the radiation direction angle of the LED illumination light source ⁇ arctan (D/Z)
  • D is the optical center of the LED illumination light source radiation system and the optical center of the iris zoom focusing optical imaging system Distance
  • Z is the working distance of the iris zoom focusing optical imaging system.
  • is the half field angle of the iris zoom focusing optical imaging system.
  • PXiris is the pixel resolution in the X horizontal direction of the iris zoom focusing optical imaging system, pixel.
  • PYiris is the Y vertical pixel resolution of the iris zoom focusing optical imaging system, pixel.
  • is the solid angle of the radiation system of the LED illumination light source, in sr steradian.
  • Ipeak is the peak value of the radiant intensity of the LED illuminating light source radiation system, in mw/sr.
  • f( ⁇ ) is the normalized distribution function of the radiation intensity of the LED illumination light source radiation system.
  • OP is the constant total optical power of the LED illumination light source radiation system, in mw.
  • is the relative contrast of the imaging image surface of the predetermined custom iris zoom focusing optical imaging system receiving light radiation, such as 0.5 Or 0.707, higher means the relative illuminance is more evenly distributed.
  • the iris zoom focus optical imaging system 's near-end working radius/distance Rnear/Znear's field of view FOViris-near124.
  • the LED illumination light source radiates the left and right sides of the LED illumination light source 130L/130R of the system.
  • the near-end working radius/distance is Rnear/Znear
  • the left and right side LED illumination light sources 131L/131R of the LED illumination light source radiation system At the far end working radius/distance Rfar/Zfar, the solid angle of the radiation intensity of the left/right illuminating light source of the LED illumination light source radiation system is matched to the far end working radius/distance Rfar/Zfar field of view angle of the iris zoom focusing optical imaging system FOViris-far132L/132R.
  • the solid angle of the radiation intensity of the left/right illuminating light source of the LED illumination light source radiation system is matched with the near-end working radius/distance Rnear/Znear field of view angle of the iris zoom focusing optical imaging system FOViris-near133L/133R.
  • the left/right illuminating light source radiation intensity direction angle of the LED illumination light source radiation system matches the near-end working radius/distance Rnear/Znear134L/134R of the iris zoom focusing optical imaging system.
  • the left/right illuminating light source radiation intensity direction angle of the LED illumination light source radiation system matches the distal working radius/distance Rfar/Zfar135L/135R of the iris zoom focusing optical imaging system.
  • the present invention can realize the LED illumination light source radiation system with constant total light power in essence, by dynamically changing the radiation intensity of the LED illumination light source, the light radiation intensity of the solid angle distribution is changed by the same amount, regardless of the iris zoom focusing optical imaging.
  • How the system changes in the far/near-end working radius [Rfar, Rnear]/distance [Zfar, Znear] and the corresponding field of view [FOViris-far, FOViris-near] according to the formula Eiris( ⁇ , ⁇ ) is kept close to constant , And can fully match the working radius/distance and the corresponding iris optical zoom focusing optical imaging system's field of view angle.
  • Eimage( ⁇ , ⁇ ) t*1/8/(1+ ⁇ ) 2 *cos 4 ( ⁇ )* ⁇ *Eiris( ⁇ , ⁇ )/FNO 2
  • is the imaging incident angle of the iris zoom focusing optical imaging system
  • [0, ⁇ ]
  • is the optical constant coefficient of the iris biological tissue reflectivity
  • 0.12-0.15 is the transmission of the iris zoom focusing optical imaging system Rate constant coefficient.
  • Eimage is constant, that is, the imaged image brightness Iimage is constant.
  • QE is the photon-electronic quantum conversion efficiency unit e-/(mw*um 2 )/s
  • G is the unit conversion gain unit mv/e-
  • ADC is the analog voltage/digital brightness conversion unit LSB/mv
  • S is the unit pixel area The unit is um 2 .
  • CMOS SENSOR technology performs photon-electronic quantum conversion using PD silicon-based photodiodes, whose efficiency is not ideal.
  • Cutting-edge QF quantum film or OPF organic photosensitive film and other technologies have natural high quantum conversion efficiency to infrared photons, global reset/global The properties of a global shutter are ideally preferred.
  • the LED illumination light source radiation system is controlled by an array combination with different radiation direction angles and radiation intensity solid angles, so as to match the corresponding iris zoom focusing optical imaging system's field of view range [FOViris-far, FOViris-near], Working radius range [Rfar,Rnear], or working distance range [Zfar, Znear].
  • the present invention realizes the redistribution of the weight value of the radiation system of the LED illumination light source with a constant total light power in essence to realize the field of view angle range [FOViris-far, FOViris-near] and the working radius of the corresponding iris zoom focusing optical imaging system [FOViris-far, FOViris-near]
  • the range [Rfar, Rnear], or the working distance range [Zfar, Znear] is equivalently fitted in response to the corresponding solid angle of the radiant intensity of the LED lighting source.
  • OPi is the optical power of the LED illuminating light source radiation system with different radiation direction angles and solid angles of radiation intensity.
  • Wi is the weight value corresponding to OPi.
  • i is the number of LED illumination light source radiation systems with different radiation direction angles and radiation intensity solid angles.
  • OP is the constant total optical power of the radiation system of the LED lighting source.
  • An example of combined control of the corresponding solid angle of the radiant intensity of the LED illumination light source and the constant total optical power OP is allocated to achieve any given working distance Z.
  • OP the constant total optical power of the LED illuminating light source radiation system corresponding to the working distance Z.
  • OPfar as the optical power of the LED illumination light source radiation system corresponding to the remote working distance Zfar.
  • Wfar is the weight value corresponding to OPfar.
  • OPnear as the optical power of the near-end LED illumination light source radiation system corresponding to the near-end working distance Znear.
  • Wnear is the weight value corresponding to OPnear.
  • Wfar [cos 3 ( ⁇ z)*Z 2 -cos 3 ( ⁇ near)*Znear 2 ]/[cos 3 ( ⁇ far)*Zfar 2 -cos 3 ( ⁇ near)*Znear 2 ].
  • Wnear] [cos 3 ( ⁇ far ) * Zfar 2 -cos 3 ( ⁇ z) * Z 2] / [cos 3 ( ⁇ far) * Zfar 2 -cos 3 ( ⁇ near) * Znear 2].
  • ⁇ z is the radiation direction angle of the radiation system of the LED illumination light source at the Z working distance.
  • ⁇ far is the radiation direction angle of the LED illumination light source radiation system at the remote working distance.
  • ⁇ near is the radiation direction angle of the near-end working distance LED illumination light source radiation system.
  • Wnear [Zfar 2 -Z 2 ]/[Zfar 2 -Znear 2 ].
  • the optical power OPfar and OPnear of the LED illumination light source radiation system with different radiation direction angles and radiation intensity solid angles can achieve any given work.
  • the optical power OPfar and OPnear of the LED illumination light source radiation system with different radiation direction angles and radiation intensity solid angles at the far end working distance Zfar and the near end working distance Znear
  • An example of combined control of the corresponding solid angle of the radiant intensity of the LED illumination light source and the constant total optical power OP is allocated to achieve any given working distance Z.
  • OP the constant total optical power of the LED illumination light source radiation system corresponding to the working distance Z
  • f( ⁇ )z the normalized distribution function of the radiation intensity corresponding to OP
  • OPfar as the optical power of the LED illumination light source radiation system corresponding to the remote working distance Zfar.
  • Wfar is the weight value corresponding to OPfar
  • f( ⁇ )far is the normalized distribution function of the radiation intensity corresponding to OPfar.
  • OPnear as the optical power of the near-end LED illumination light source radiation system corresponding to the near-end working distance Znear.
  • Wnear is the weight value corresponding to OPnear
  • f( ⁇ )near is the normalized distribution function of the corresponding OPnear radiation intensity.
  • Wfar [cos 3 ( ⁇ z)*f( ⁇ )z*Z 2 -cos 3 ( ⁇ near)*f( ⁇ )near*Znear 2 ]/[cos 3 ( ⁇ far)*f( ⁇ )far*Zfar 2- cos 3 ( ⁇ near)*f( ⁇ )near*Znear 2 ].
  • Wnear [cos 3 ( ⁇ far)*f( ⁇ )far*Zfar 2 -cos 3 ( ⁇ z)*f( ⁇ )z*Z 2 ]/[cos 3 ( ⁇ far)*f( ⁇ )far*Zfar 2- cos 3 ( ⁇ near)*f( ⁇ )near*Znear 2 ].
  • Wfar [cos 3 ( ⁇ z)*f( ⁇ ( ⁇ ))z*Z 2 -cos 3 ( ⁇ near)*f( ⁇ ( ⁇ ))near*Znear 2 ]/[cos 3 ( ⁇ far)*f( ⁇ ( ⁇ ))far*Zfar 2 -cos 3 ( ⁇ near)*f( ⁇ ( ⁇ ))near*Znear 2 ].
  • Wnear [cos 3 ( ⁇ far)*f( ⁇ ( ⁇ ))far*Zfar 2 -cos 3 ( ⁇ z)*f( ⁇ ( ⁇ ))z*Z 2 ]/[cos 3 ( ⁇ far)*f( ⁇ ( ⁇ ))far*Zfar 2 -cos 3 ( ⁇ near)*f( ⁇ ( ⁇ ))near*Znear 2 ].
  • ⁇ z is the radiation direction angle of the radiation system of the LED illumination light source at the Z working distance.
  • ⁇ far is the radiation direction angle of the LED illumination light source radiation system at the remote working distance.
  • ⁇ near is the radiation direction angle of the near-end working distance LED illumination light source radiation system.
  • f( ⁇ ( ⁇ ))z is the normalized distribution function value of the radiation intensity corresponding to the radiation system of the Z working distance LED illumination light source at the solid angle of the radiation intensity of ⁇ ( ⁇ ).
  • f( ⁇ ( ⁇ ))far is the normalized distribution function value of the radiation intensity corresponding to the radiation system of the remote working distance LED illumination light source at the solid angle of the radiation intensity of ⁇ ( ⁇ ).
  • f( ⁇ ( ⁇ ))near is the normalized distribution function value of the radiation intensity corresponding to the ⁇ ( ⁇ ) radiation intensity solid angle of the near-end working distance LED illumination light source radiation system.
  • Wfar [f( ⁇ ( ⁇ ))z*Z 2 -f( ⁇ ( ⁇ ))near*Znear 2 ]/[f( ⁇ ( ⁇ ))far*Zfar 2 -f( ⁇ ( ⁇ ))near* Znear 2 ]
  • Wnear [f( ⁇ ( ⁇ ))far*Zfar 2 -f( ⁇ ( ⁇ ))z*Z 2 ]/[f( ⁇ ( ⁇ ))far*Zfar 2 -f( ⁇ ( ⁇ ))near* Znear 2 ]
  • the optical power OPfar and OPnear of the LED illumination light source radiation system with different radiation direction angles and radiation intensity solid angles can achieve any given work.
  • the LED illumination light source radiation intensity solid angle combination control weight value redistributed optical radiation power within the field of view angle range of the optical imaging system changes the iris surface by the same amount
  • the illuminance is kept close to constant according to the formula, and can completely match the field of view of the corresponding iris optical zoom focusing optical imaging system.
  • the LED illumination light source radiation system and the iris zoom focusing optical imaging system are combined and configured to have combined control in response to the synchrotron radiation intensity direction angle and the radiation intensity solid angle, so as to realize the response of the LED illumination light source radiation system in different 3D physical space points.
  • the corresponding matching relationship between the field of view angles of the iris zoom focusing optical imaging system corresponding to different working radii/distances meets the constant imaging image brightness within the predetermined working field of view and working distance, constant imaging image contrast, constant The radiant power of the LED lighting source system and the constant irradiance of the iris of the eye.
  • the LED illumination light source radiation system and the iris zoom focusing optical imaging system are configured as a global pixel exposure (integration) and illumination radiation combined imaging mode of synchronous pulse external triggering or synchronous pulse internal triggering.
  • the synchronization pulse exposure (integration) time and the synchronization pulse illumination radiation time Tpulse ⁇ m/(PR*speed), speed is the predetermined controlled movement speed such as 1m/s
  • m is the predetermined controlled motion blur image pixel scale, m ⁇ 10pxiels.
  • LED illumination light source radiation system generates synchronous pulse illumination radiation on the iris surface irradiance Tpulse*Fpulse*Eiris( ⁇ ) ⁇ 10mw/cm2, to ensure that the eye radiation biological safety.
  • the iris zoom focusing optical imaging system realizes the global pixel exposure (integration) and the combined imaging mode of the illumination radiation in the synchronization pulse external trigger or the synchronization pulse internal trigger mode under the combination of the filter.
  • Anti-interference performance under various light interference conditions Such as outdoor solar environment up to 10,000 lux or more.
  • the ultra-high resolution image imaging sensor of the present invention has a resolution of at least 8K, which is above 8000*4000. Considering such ultra-high resolution bandwidth and frame rate are limited, the present invention can use binning or subsampling in image quality processing.
  • the imaging mode improves the preprocessing speed of image imaging quality.
  • the present invention adopts multiple groups of iris zoom focusing optical imaging system arrays to realize the corresponding group of several times to increase the field of view angle. It can be equivalently understood as the angle of view corresponding to the resolution of the corresponding multiple.
  • the protective window 123 can be made of full-transmission tempered optical glass, or more preferably, a filter that reflects visible light below 700nm and transmits infrared light from 700-900nm, which can protect the internal optical components while the user cannot observe the internal structure by reflecting visible light Provide users with visual feedback in their natural state. Furthermore, filtering visible light can improve the iris zoom focusing optical imaging system to eliminate the interference of external non-imaging wavelength stray light, and further improve the image quality SNR.
  • the invention provides a long-distance large-field-of-view iris optical imaging device and method, which simultaneously realizes the constant field of view angle and radiation illuminance in a large range.

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Abstract

本发明提供一种远距离大视场虹膜光学成像的装置,包括:虹膜光学跟踪系统,包括3D深度成像单元;虹膜变焦聚焦光学成像系统,包括光学变焦聚焦透镜组和超高分辨率图像成像传感器,用于根据3D物理空间点坐标执行虹膜成像的焦距和/或聚焦位置调整,超高分辨率图像成像传感器物理成像;LED照明光源辐射系统,包括辐射强度立体角和/或辐射强度方向角,用于根据3D物理空间点坐标执行响应于不同工作半径/距离对应的虹膜变焦聚焦光学成像系统的视场角之间匹配关系的组合控制;图像处理和驱动控制,实现各系统单元间的驱动和反馈控制。本发明提供的一种远距离大视场虹膜光学成像的装置及方法,同时实现大范围时视场角和辐射照度恒定。

Description

一种远距离大视场虹膜光学成像的装置及方法 技术领域
本发明涉及光学成像技术领域,特别涉及一种远距离大视场虹膜光学成像的装置及方法。
背景技术
已知用于虹膜成像装置存在以下缺陷,在远工作距离和大工作视场场景下获得图像的成像时间超过1‐3s,用户无法在如此长时间内保持一致相对静止,归因于图像虹膜直径要求>200pixel的大放大倍率要求,导致即使非常轻微移动都能造成超过虹膜成像系统视场需要重新调整视场,变焦聚焦,照明。
此外,传统测距包括软件映射虹膜直径或双眼距离,因为归因于人群中变化差异大于20%导致误差过大而无法提供精确工作距离信息直接影响整体性能,同样红外,超声,tof等物理测距在远工作距离和大工作视场场景下也误差过大无法提供精确工作距离信息,同时已知技术存在景深,图像亮度,图像相对照度,照明光源辐射强度,眼睛虹膜受辐射照度等图像质量在远工作距离和大工作视场场景下也无法保证一致性,甚至相差数倍,传统的照明光源采用随工作距离平方反比变化调节,非恒定光源辐射强度(比如工作距离2‐3倍范围,视场角变化2‐3倍,辐射强度变化4‐9倍),导致无法同时满足大范围时视场角和辐射照度恒定的要求。
传统提高成像视场采用机械云台结构,导致控制复杂,定位误差精确度低,稳定性可靠性低,功耗体积和噪声寿命都存在严重问题,在等待云台位置调整之后开始成像时间耗时非常严重成像速度非常缓慢。
因此,针对现有技术中的在远工作距离和大工作视场场景下上述技术问题,需要一种远距离大视场虹膜光学成像的装置及方法。
发明内容
本发明的一个方面在于提供一种远距离大视场虹膜光学成像的装置,所述装置包括:
虹膜光学跟踪系统,虹膜变焦聚焦光学成像系统,LED照明光源辐射系统,图像显示反馈系统,图像处理和驱动控制系统;
所述虹膜光学跟踪系统包括3D深度成像单元,用于执行3D物理空间点坐标获取;
所述的虹膜变焦聚焦光学成像系统包括光学变焦聚焦透镜组和超高分辨率图像成像传感器,用于根据3D物理空间点坐标执行虹膜成像的焦距和/或聚焦位置调整,超高分辨率图像成像传感器物理成像;
所述LED照明光源辐射系统包括辐射强度立体角和/或辐射强度方向角,用于根据3D物理空间点坐标执行响应于不同工作距离对应的虹膜变焦聚焦光学成像系统的视场角之间匹配关系的组合控制;
所述的图像显示反馈系统包括显示屏用于实时显示当前图像和/或状态信息;
所述的图像处理和驱动控制系统连接虹膜光学跟踪系统,虹膜变焦聚焦光学成像系统,LED照明光源辐射系统,图像显示反馈系统,并实现各系统单元间的驱动和反馈控制。
所述3D深度成像单元成像视场角大于等于虹膜变焦聚焦光学成像系统的成像视场角。
优选地,所述3D深度成像单元包括采用3D TOF深度成像或结构光深度成像,或双目立体视觉成像。
优选地,所述超高分辨率图像成像传感器至少8K分辨率。
优选地,所述LED照明光源辐射系统的辐射强度方向角度,满足关系:ψ=arctan(D/Z),其中,
定义在LED照明光源辐射系统的辐射强度峰值方向对应的中心线和虹膜变焦聚焦光学成像系统的光轴间夹角,D为LED照明光源辐射系统的光学中心和虹膜变焦聚焦光学成像系统光学中心的距离,Z为虹膜变焦聚 焦光学成像系统的工作距离。
优选地,所述LED照明光源辐射系统的辐射强度立体角,满足关系:Ω(ω)=4π*sin 2(ω)单位球面度sr,其中,
ω=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/((1+β)*EFLiris))
=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/(β*Z)),ω为虹膜变焦聚焦光学成像系统的半视场角,
PXiris为虹膜变焦聚焦光学成像系统的X水平方向像素分辨率,
PYiris为虹膜变焦聚焦光学成像系统的Y垂直方向像素分辨率,
EFLiris为焦距位置,
β=PR*PSiris,PR为虹膜物理直径像方分辨率,
PSiris为虹膜变焦聚焦光学成像系统的超高分辨率图像成像传感器的像素单位分辨率,
Z为虹膜变焦聚焦光学成像系统的工作距离。
优选地,所述LED照明光源辐射系统和虹膜变焦聚焦光学成像系统被配置为:
在滤光片的结合下同步脉冲外触发或同步脉冲内触发方式的全局像素曝光(积分)和照明辐射的组合成像模式,其中:
所述的组合成像模式的同步脉冲曝光(积分)时间和同步脉冲照明辐射时间Tpulse<m/(PR*speed),
speed为预定控制的运动速度,单位m/s,
PR为虹膜物理直径像方分辨率,
m为预定控制的运动模糊图像像素尺度,单位pixel;
所述的组合成像模式的同步脉冲曝光(积分)频率和同步脉冲照明辐射频率Fpulse,所述同步脉冲照明辐射频率Fpulse=[10,30]Hz,
所述LED照明光源辐射系统产生同步脉冲照明辐射在虹膜表面的受辐射照度Tpulse*Fpulse*Eiris(ω)<10mw/cm 2
Eiris(ω)为虹膜表面上受辐射照度。
本发明的另一个方面在于提供一种远距离大视场虹膜光学成像的方法,所述方法包括:
图像处理和驱动控制系统执行虹膜光学跟踪系统,虹膜变焦聚焦光学成像系统,LED照明光源辐射系统,图像显示反馈系统之间的驱动和反馈控制过程:
a、反馈控制虹膜光学跟踪系统,通过虹膜光学跟踪系统的3D深度成像单元获取虹膜关键点3D坐标,转换相对坐标为3D物理空间点,实现实时同步虹膜光学成像跟踪;
b、反馈控制虹膜变焦聚焦光学成像系统和超高分辨率图像成像传感器,根据3D物理空间点坐标,实现实时同步光学变焦聚焦透镜组的焦距和/或聚焦位置的反馈控制,超高分辨率图像成像传感器物理成像;
c、反馈控制LED照明光源辐射系统,根据3D物理空间点坐标,实现实时同步响应于不同工作距离对应的虹膜变焦聚焦光学成像系统的视场角之间匹配关系的LED照明光源辐射强度方向角度和/或LED照明光源辐射强度立体角的反馈控制;
d、反馈控制图像显示反馈系统实时显示当前图像和/或状态信息;
所述图像显示反馈系统实现实时同步显示当前图像为3D深度成像单元成像的红外图像,RGB可见光单元成像图像或虹膜变焦聚焦光学成像图像。
优选地,反馈控制虹膜成像跟踪系统,包括:
a1、根据预定的工作视场范围FOV,定义3D深度成像单元的视场角FOVface和有效成像焦距EFLface:
EFLface=[(PXface 2+PYface 2) 1/2*PSface/2]/tan(FOVface/2)
PXface为3D深度成像单元的X水平方向像素分辨率;
PYface为3D深度成像单元的Y垂直方向像素分辨率;
PSface为3D深度成像单元的像素单位分辨率;
FOVface为3D深度成像单元的视场角度,FOVface=FOV;
EFLface为3D深度成像单元的有效成像焦距。
a2、定义3D深度成像单元控制获取虹膜关键点:
a21、获取3D深度成像单元的亮度(红外灰度阶)图像Ii(x,y)和深度距离图像Iz(x,y);
a22、在亮度图像Ii(x,y)中检测人脸区域,在人脸区域进一步定位左右眼中心坐标(xl,yl)和(xr,yr);
a23、获取在深度距离图像Iz(x,y)中左右眼中心对应坐标的位置的深度距离信息,
z=[Iz(xl,yl)+lz(xr,yr)]/2
z=Iz((xl+xr)/2,(yl+yr)/2);
a24、产生3D深度成像单元像方关键参考点,
KPface(xe,ye,z):KPface(xe,ye,z)=KPface((xl+xr-PXface)/2*PS face,(yl+yr-PYface)/2*PSface,z);
a25、产生3D深度成像单元物方关键参考点KPface(Xe,Ye,Ze):KPface(Xe,Ye,Ze)=KPface(xe*z/EFLface,ye*z/EFLface,z)。
a3、建立3D深度成像单元的物方关键参考点坐标KPface(Xe,Xe,Ze)相对虹膜变焦聚焦光学成像系统的3D物理空间点Piris(X,Y,Z)坐标变换,Piris(X,Y,Z)=(Xe-Xoffset,Xe-Yoffset,Ze-Zoffset),
(Xoffset,Yoffset,Zoffset)为3D深度成像单元相对虹膜变焦聚焦光学成像系统的3D物理位置坐标偏移。
优选地,反馈控制虹膜变焦聚焦光学成像系统,包括:
b1、执行虹膜变焦聚焦光学成像系统的变焦聚焦参数同步控制;
b11、执行对虹膜变焦聚焦光学成像系统的焦距参数控制,实现焦距位置保持恒定的预定放大倍率即相同成像虹膜直径,
焦距位置EFLiris=Z*β/(1+β),
其中,β=PR*PSiris,PR为虹膜物理直径像方分辨率,
PSiris虹膜变焦聚焦光学成像系统的图像成像传感器的像素单位分辨率,
Z为虹膜变焦聚焦光学成像系统的工作距离;
b2、执行对虹膜变焦聚焦光学成像系统的聚焦参数控制,实现聚焦位置在像方景深范围内,
聚焦位置FOCUS=β*[Z-kDOF,Z+kDOF],
其中,k步数控制范围,DOF=2*FNO*SOC*(1+β)/β 2,其中,FNO为虹膜变焦聚焦光学成像系统的光圈参数,
SOC为为虹膜变焦聚焦光学成像系统的最小物理光斑分辨率参数。
优选地,所述反馈控制LED照明光源辐射系统,包括:
c1、执行LED照明光源辐射系统的照明光源辐射强度方向角度参数控制,
LED照明光源辐射方向角度ψ=arctan(D/Z),
定义在LED照明光源辐射系统的辐射强度峰值方向对应的中心线和虹膜变焦聚焦光学成像系统的光轴间夹角,D为LED照明光源辐射系统的光学中心和虹膜变焦聚焦光学成像系统光学中心的距离,Z为虹膜变焦聚焦光学成像系统的工作距离;
c2、执行对LED照明光源辐射系统的LED照明光源辐射强度立体角的参数控制,
LED照明光源辐射强度立体角Ω(ω)=4π*sin 2(ω)单位球面度sr,其中,
ω=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/((1+β)*EFLiris))
=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/(β*Z)),ω为虹膜变焦聚焦光学成像系统的半视场角,
PXiris为虹膜变焦聚焦光学成像系统的X水平方向像素分辨率,
PYiris为虹膜变焦聚焦光学成像系统的Y垂直方向像素分辨率,
EFLiris为焦距位置,
β=PR*PSiris,PR为虹膜物理直径像方分辨率,
PSiris为虹膜变焦聚焦光学成像系统的超高分辨率图像成像传感器的像素单位分辨率,
Z为虹膜变焦聚焦光学成像系统的工作距离。
本发明提供的一种远距离大视场虹膜光学成像的装置及方法,同时实现大范围时视场角和辐射照度恒定,具有以下优势:
1.恒定放大倍率即相同的成像图像虹膜直径。
2.响应于视场和工作距离及景深范围内成像速度0.1s以内。
3.恒定的成像景深。
4.恒定的成像图像亮度。
5.恒定的成像图像相对照度。
6.恒定的LED照明光源系统辐射总光功率。
7.恒定的眼睛虹膜受辐射照度,并满足眼睛生物安全辐射上限。
8.移动速度到1m/s不受运动模糊影响,对抗各种环境光>10,000lux噪声条件干扰。
9.无机械运动部件高可靠稳定实现工作距离大于1m,视场范围大于60度。
应当理解,前述大体的描述和后续详尽的描述均为示例性说明和解释,并不应当用作对本发明所要求保护内容的限制。
附图说明
参考随附的附图,本发明更多的目的、功能和优点将通过本发明实施方式的如下描述得以阐明,其中:
图1示意性示出了本发明一个实施例中远距离大视场虹膜光学成像的装置的原理示意图。
附图标记:
100远距离大视场虹膜光学成像的装置,
110 3D深度成像单元红外VCSEL光源,
111深度成像单元红外的成像透镜和图像成像传感器,
114可见光RGB图像成像单元,
115 3D深度成像单元的视场角即预定的工作视场角FOVface,
116预定的近端工作半径Rnear,
117预定的近端工作距离Znear,
118预定的远端工作半径Rfar,
119预定的远端工作距离Zfar,
120虹膜变焦聚焦光学成像系统的变焦聚焦成像透镜组,
121虹膜变焦聚焦光学成像系统的滤光片,
122虹膜变焦聚焦光学成像系统的超高分辨率图像成像传感器,
123保护窗口,
124虹膜变焦聚焦光学成像系统的近端工作半径/距离Rnear/Znear的视场角FOViris‐near,
125虹膜变焦聚焦光学成像系统的远端工作半径/距离Rfar/Zfar的视场角FOViris‐far,
126虹膜变焦聚焦光学成像系统的近端工作半径/距离Rnear/Znear的物方平面成像区域,
127虹膜变焦聚焦光学成像系统的远端工作半径/距离Rfar/Zfar的物方平面成像区域,
130L/130R在远端工作半径/距离Rfar/Zfar时LED照明光源辐射系统的左右侧LED照明光源,
131L/131R在近端工作半径/距离Rnear/Znear时LED照明光源辐射系统的左右侧LED照明光源,
132L/132R在远端工作半径/距离Rfar/Zfar时LED照明光源辐射系统的左/右侧照明光源的辐射强度立体角,匹配虹膜变焦聚焦光学成像系统的远端工作半径/距离Rfar/Zfar的视场角FOViris‐far,
133L/133R在近端工作半径/距离Rnear/Znear时LED照明光源辐射系统的左/右侧照明光源的辐射强度立体角,匹配虹膜变焦聚焦光学成像系统的近端工作半径/距离Rnear/Znear的视场角FOViris‐near,
134L/134R在近端工作半径/距离Rnear/Znear时LED照明光源辐射系统的左/右侧照明光源辐射强度方向角度,匹配虹膜变焦聚焦光学成像系统的近端工作半径/距离Rnear/Znear,
135L/135R在远端工作半径/距离Rfar/Zfar时LED照明光源辐射系统的左/右侧照明光源辐射强度方向角度,匹配虹膜变焦聚焦光学成像系统的远端工作半径/距离Rfar/Zfar,
150图像处理和驱动控制系统,
160图像显示反馈系统。
具体实施方式
通过参考示范性实施例,本发明的目的和功能以及用于实现这些目的和功能的方法将得以阐明。然而,本发明并不受限于以下所公开的示范性实施例;可以通过不同形式来对其加以实现。说明书的实质仅仅是帮助相关领域技术人员综合理解本发明的具体细节。
在下文中,将参考附图描述本发明的实施例。在附图中,相同的附图标记代表相同或类似的部件,或者相同或类似的步骤。
实施例一:
如图1所示本发明一个实施例中远距离大视场虹膜光学成像的装置的原理示意图,根据本发明本实施例中,一种远距离大视场虹膜光学成像的装置100,包括:虹膜光学跟踪系统,虹膜变焦聚焦光学成像系统,LED照明光源辐射系统,图像显示反馈系统160,图像处理和驱动控制系统150。
虹膜光学跟踪系统包括3D深度成像单元。
3D深度成像单元可采用3D TOF深度成像或结构光深度成像(例如940nm红外VCSEL光源110,成像透镜和图像成像传感器111),或双目立体视觉成像(LED照明光源,固定间隔距离安装的2组参数对称的成像透镜和图像成像传感器)提供深度图像信息。
虹膜变焦聚焦光学成像系统包括光学变焦聚焦透镜组120,光学滤光片121,超高分辨率图像成像传感器122。
LED照明光源辐射系统包括LED照明光源辐射强度立体角和/或辐射强度方向角度组合控制。
图像显示反馈系统160包括显示屏,用于实时显示当前图像和/或状态信息。
所述3D深度成像单元成像视场角115大于等于虹膜变焦聚焦光学成像系统的成像视场角124/125。
所述超高分辨率图像成像传感器122至少8K分辨率。
图像处理和驱动控制系统150连接虹膜光学跟踪系统,虹膜变焦聚 焦光学成像系统,LED照明光源辐射系统,图像显示反馈系统,并实现各系统单元间的驱动和反馈控制。
根据本发明本实施例一种远距离大视场虹膜光学成像的方法,包括:图像处理和驱动控制系统执行各系统单元间的驱动和反馈控制过程如下:
a、反馈控制虹膜成像跟踪系统,通过3D深度成像单元获取虹膜关键点3D坐标,转换相对坐标为3D物理空间点,实现实时同步虹膜光学成像跟踪。
b、反馈控制虹膜变焦聚焦光学成像系统,根据3D物理空间点坐标,实现实时同步光学变焦聚焦透镜组的焦距和聚焦位置的反馈控制,超高分辨率图像成像传感器物理成像反馈控制。
c、反馈控制LED照明光源辐射系统,根据3D物理空间点坐标,实现实时同步响应于不同工作距离对应的虹膜变焦聚焦光学成像系统的视场角之间匹配关系的LED照明光源辐射强度方向角度和/或LED照明光源辐射强度立体角的反馈控制。
d、反馈控制图像显示反馈系统实时显示当前图像和/或状态信息。
图像显示反馈系统实现实时同步显示当前图像为3D深度成像单元成像的红外亮度图像,RGB可见光单元成像图像或虹膜变焦聚焦光学成像图像。
根据本发明的实施例,具体的步骤包括:
a1、根据预定的工作视场范围FOV,定义3D深度成像单元的视场角FOVface115和有效成像焦距EFLface。
EFLface=[(PXface 2+PYface 2) 1/2*PSface/2]/tan(FOVface/2),
PXface为3D深度成像单元的X水平方向像素分辨率,pixel;
PYface为3D深度成像单元的Y垂直方向像素分辨率,pixel;
PSface为3D深度成像单元的像素单位分辨率,um/pixel;
FOVface为3D深度成像单元的视场角,FOVface=FOV;
EFLface为3D深度成像单元的有效成像焦距,mm。
典型参数计算如下:
PXface=640pixels,PYface=480pixels,PSface=5.6um/pixel,FOVface=FOV=77度,EFLface=2.8mm。
a2、定义3D深度成像单元控制获取虹膜关键点。
a21、获取3D深度成像单元的亮度(红外灰度阶)图像Ii(x,y)和深度距离图像Iz(x,y)。
a22、在亮度图像Ii(x,y)中检测人脸区域,在人脸区域进一步定位左右眼中心坐标(xl,yl)和(xr,yr)。
目前应用公知的基于深度学习的卷积神经网络CNN级联模型可以可靠准确的实现人脸区域检测和人眼定位功能。
具体本实施例为了提高检测定位眼睛性能,采用独立或联合可见光RGB图像成像单元114,预先进行3D深度成像单元和可见光RGB图像成像单元114的的标定配准,然后进一步检测RGB图像中人脸区域和人眼定位提高精度和可靠性。另外RGB成像单元可以用于装置在待机状态时检测人脸触发系统进入正常工作状态,降低系统待机功耗。更进一步可见光RGB图像成像单元成像图像被用于图像显示反馈系统实时显示当前图像。
a23、获取在深度距离图像Iz(x,y)中左右眼中心对应坐标的位置的深度距离信息,
z=[Iz(xl,yl)+lz(xr,yr)]/2,
z=Iz((xl+xr)/2,(yl+yr)/2)。
具体本实施例为了提高距离信息测量精度和可靠性性能,采用提取左右眼中心坐标位置的局部区域内有效像素过滤干扰像素,如中值滤波,或过滤灰度亮度图像中过高亮度或过低亮度的像素,或深度距离图像中距离过远或距离过近的像素等。
a24、产生3D深度成像单元像方关键参考点KPface(xe,ye,z):KPface(xe,ye,z)=KPface((xl+xr‐PXface)/2*PSface,(yl+yr‐PYface)/2*PSface,z)。
a25、产生3D深度成像单元物方关键参考点KPface(Xe,Ye,Ze):KPface(Xe,Ye,Ze)=KPface(xe*z/EFLface,ye*z/EFLface,z)。
a3、建立3D深度成像单元的物方关键参考点坐标KPface(Xe,Xe,Ze)相对虹膜变焦聚焦光学成像系统的3D物理空间点Piris(X,Y,Z)坐标变换,
Piris(X,Y,Z)=(Xe‐Xoffset,Xe‐Yoffset,Ze‐Zoffset),
其中,(Xoffset,Yoffset,Zoffset)为3D深度成像单元相对虹膜变焦聚焦光学成像系统的3D物理位置坐标偏移。
执行虹膜变焦聚焦光学成像系统的变焦聚焦参数同步控制,包括:
b1、执行对虹膜变焦聚焦光学成像系统的焦距参数控制,实现焦距位置保持恒定的预定放大倍率即相同成像虹膜直径。
焦距位置EFLiris=Z*β/(1+β)
其中,β=PR*PSiris PR为虹膜物理直径像方分辨率pixel/mm如典型的20pixels/mm,PSiris虹膜变焦聚焦光学成像系统的超高分辨率图像成像传感器的像素单位分辨率um/pixel,如典型的3um/pixel,β=0.06。
如图1所示R为预定的工作半径,包括预定的近端工作半径Rnear116,预定的远端工作半径Rfar118,
预定的工作距离Z,包括预定的近端工作距离Znear117,预定的远端工作距离Zfar119。
如典型参数近端工作距离Znear=1m,远端工作距离Zfar=2m,分别EFLiris=56.6mm和113.2mm。
考虑到实际使用者不自主移动同时保证速度和调整频率,可以Z间隔变化一定预定范围后执行光学变焦操作。如保持相对5‐10cm范围相同的焦距,这种设计是合理的,虹膜直径本身也是因人而异存在一定差异。
b2、执行对虹膜变焦聚焦光学成像系统的聚焦参数控制,实现聚焦位置在像方景深范围内,
聚焦位置FOCUS=β*[Z‐kDOF,Z+kDOF]
其中,k步数控制范围,k=[1,2],步长为STEP=β*DOF,如k=2,包括‐2STEP,‐STEP,0,+STEP,2STEP共5个范围,DOF=2*FNO*SOC*(1+β)/β 2,其中,FNO为虹膜变焦聚焦光学成像系统的光圈参数,参数范围[PF,2PF],PF=PSiris/(1um/pixel);SOC为为虹膜变焦聚焦光学成像系统 的最小物理光斑分辨率参数,参数典型值为SOC=2*PSiris*1pixel,最大值DOF=21.2mm。
归因于深度信息的误差,虹膜变焦聚焦光学成像系统在实际生产制造过程精度机械误差,个体偏差等,产生2k+1倍步长控制位置,步长为β*DOF,一般3‐5步长范围完全在预定的像方聚焦位置,保证聚焦位置在+‐DOF/2的物方景深范围内(等价的,+‐β*DOF/2的像方景深范围内),同时如此少量控制步数能保证在0.1s完成。
本发明上述设计保证具有恒定景深范围,并同时实现聚焦位置在像面景深范围内。
理想的非球面光学玻璃/塑料混合2片液体透镜liquid lens分别独立控制焦距EFLiris和聚焦FOCUS,上述设计需要焦距和和聚焦位置都转换为对应设计的成像光学系统2片液体镜头的屈光度为单位规格的数值,相比传统步进电机驱动的复杂凸轮曲线控制,归因于液体透镜具有屈光度和电压/电流对应的线性响应光学属性关系,可大大简化驱动控制过程,同时如此设计可大量减少整体成像系统组件数量(3‐4组群12‐16片)。
同时没有任何传统螺杆或齿轮连接驱动的机械传动部件,无使用寿命限制,控制精度和重复性也有本质性的提高。
本发明在实践中,目前液体透镜存在受限的通光孔径典型如6‐10mm,和受限的屈光范围‐10到+20屈光度,在大屈光度时波前误差增加到λ/10,但归因于景深对FNO值,长焦距应用要求,适合虹膜变焦聚焦光学成像系统。光学设计者利用液体透镜特性技巧可通过优化光路设计解决,如光路中选择合适的出入射光瞳设计FNO解决通光孔径,变焦部分光学系统初始设计采用设置变焦液体镜头在0屈光度光学功率时工作在远端工作距离时对应最大焦距,聚焦部分光学系统初始设计采用设置聚焦液体镜头在0屈光度光学功率时工作在远端工作距离时对应的像面位置。
执行对LED照明光源辐射系统的LED照明光源辐射强度方向角度和/或LED照明光源辐射强度立体角的参数控制,实现在不同3D物理空间点坐标响应于不同工作距离对应的虹膜变焦聚焦光学成像系统的视场角范 围之间关系的匹配,如图1所示。
c1、执行LED照明光源辐射系统的照明光源辐射强度方向角度参数控制。
LED照明光源辐射方向角度ψ=arctan(D/Z)
定义在LED照明光源辐射系统的辐射强度峰值方向对应的中心线和虹膜变焦聚焦光学成像系统的光轴间夹角,D为LED照明光源辐射系统的光学中心和虹膜变焦聚焦光学成像系统光学中心的距离,Z为为虹膜变焦聚焦光学成像系统的工作距离。
等价的定义,在LED照明光源辐射系统的辐射强度峰值方向对应的中心线和虹膜变焦聚焦光学成像系统的物方平面夹角ψ',ψ=90‐ψ'。
C2、执行对LED照明光源辐射系统的LED照明光源辐射强度立体角的参数控制。
LED照明光源辐射强度立体角Ω(ω)=4π*sin 2(ω)单位球面度srω=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/((1+β)*EFLiris))=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/(β*Z))
ω为虹膜变焦聚焦光学成像系统的半视场角。
PXiris为虹膜变焦聚焦光学成像系统的X水平方向像素分辨率,pixel。
PYiris为虹膜变焦聚焦光学成像系统的Y垂直方向像素分辨率,pixel。
由于真实物理光学如凸透镜和或凹面反射镜等无法制造出在给定LED照明光源辐射强度立体角Ω(ω)下等密度均匀光场分别光能量(光功率)分布,既单位阶跃函数分布,而是具有特定函数分布。
Figure PCTCN2020084772-appb-000001
其中:
I(Ω)为LED照明光源辐射系统的辐射强度,单位mw/srI(Ω)=Ipeak*f(Ω)。
Ω为LED照明光源辐射系统的立体角,单位sr球面度。
Ipeak为LED照明光源辐射系统的辐射强度峰值,单位mw/sr。
f(Ω)为LED照明光源辐射系统的辐射强度归一化分布函数。
OP为LED照明光源辐射系统的恒定总光学功率,单位mw。
根据推论f(Ω(ω))=I(Ω(ω))/Ipeak。
因此,在LED照明光源辐射系统的辐射强度立体角Ω(ω)时,LED照明光源辐射系统具有辐射强度I(Ω(ω))=Ipeak*f(Ω(ω))。
定义ρ=Iρ/Ipeak=I(Ω(ω))/Ipeak=f(Ω(ω)),ρ为预定的自定义虹膜变焦聚焦光学成像系统的成像像面接受光辐射的相对照度,如0.5或0.707,更高意味相对照度分布更均匀。
本质上LED照明光源辐射强度立体角产生在虹膜表面上受辐射照度Eiris,Eiris(ω,ψ)=OP/(Ω(ω)*Z 2)*cos 3(ψ)。
当ω足够小时满足sin 2(ω)=tan 2(ω)。
如图1所示,虹膜变焦聚焦光学成像系统的近端工作半径/距离Rnear/Znear的视场角FOViris‐near124。虹膜变焦聚焦光学成像系统的远端工作半径/距离Rfar/Zfar的视场角FOViris‐far125。虹膜变焦聚焦光学成像系统的近端工作半径/距离Rnear/Znear的物方平面成像区域126。虹膜变焦聚焦光学成像系统的远端工作半径/距离Rfar/Zfar的物方平面成像区域127。在远端工作半径/距离Rfar/Zfar时LED照明光源辐射系统的左右侧LED照明光源130L/130R。在近端工作半径/距离Rnear/Znear时LED照明光源辐射系统的左右侧LED照明光源131L/131R。在远端工作半径/距离Rfar/Zfar时LED照明光源辐射系统的左/右侧照明光源的辐射强度立体角,匹配虹膜变焦聚焦光学成像系统的远端工作半径/距离Rfar/Zfar的视场角FOViris‐far132L/132R。在近端工作半径/距离Rnear/Znear时LED照明光源辐射系统的左/右侧照明光源的辐射强度立体角,匹配虹膜变焦聚焦光学成像系统的近端工作半径/距离Rnear/Znear的视场角FOViris‐near133L/133R。在近端工作半径/距离Rnear/Znear时LED照明光源辐射系统的左/右侧照明光源辐射强度方向角度,匹配虹膜变焦聚焦光学成像系统的近端工作半径/距离Rnear/Znear134L/134R。在远端工作半径/距离Rfar/Zfar时LED照明光源辐射系统的左/右侧照明光源辐射强度方向角度,匹配虹膜变焦聚焦光学成像系统的远端工作半径/距离Rfar/Zfar135L/135R。
本发明可以实现在本质上对于恒定总光功率的LED照明光源辐射系 统,通过动态改变LED照明光源辐射强度立体角分配的光辐射强度等量的改变虹膜表面受辐射照度,无论虹膜变焦聚焦光学成像系统在远端/近端工作半径[Rfar,Rnear]/距离[Zfar,Znear]及对应的视场角[FOViris‐far,FOViris‐near]如何变化,根据公式Eiris(ω,ψ)保持接近恒定,而且能完全匹配工作半径/距离及对应的虹膜光学变焦聚焦光学成像系统的视场角。
可以证明对于一个具有虹膜变焦聚焦光学成像系统的成像像面接受光辐射照度Eimage。
根据公式Eimage(ω,ψ)=t*1/8/(1+β) 2*cos 4(Φ)*μ*Eiris(ω,ψ)/FNO 2,当ω足够小时满足cos 4(Φ)=1,Φ为虹膜变焦聚焦光学成像系统的成像入射角,Φ=[0,ω],μ为虹膜生物组织反射率光学常数系数,0.12‐0.15,t为虹膜变焦聚焦光学成像系统的透过率常数系数。
Eimage是恒定的,即成像图像亮度Iimage是恒定的。
Iimage=QE*Tpulse*Eimage*ADC*G*S
QE为光子‐电子量子转换效率单位e‐/(mw*um 2)/s,G为单位转换增益单位mv/e‐,ADC为模拟电压/数字亮度转换单位LSB/mv,S为单位像素面积单位um 2
目前传统CMOS SENSOR技术执行光子‐电子量子转换的是PD硅基光电二极管其效率不理想,前沿的QF量子薄膜或OPF有机感光薄膜等技术,具有天然对红外光子高量子转换效率,global reset/global shutter全局快门的性质是理想的优选。
同时可以证明对于虹膜变焦聚焦光学成像系统的成像像面接受光辐射的相对照度ρ是恒定的,ρ=Eedge/Ecenter=Iρ/Ipeak,Eedge为成像像面边缘(视场边缘)的受辐射照度Eedge=Eimage(ω,ψ)*ρ,Ecenter为成像像面中心(视场中心)的受辐射照度,Ecenter=Eimage(ω,ψ)既成像图像亮度具有恒定的相对照度。
本发明通过LED照明光源辐射系统通过具有不同的辐射方向角和辐射强度立体角的阵列组合控制,实现匹配对应的虹膜变焦聚焦光学成像系统的视场角范围[FOViris‐far,FOViris‐near],工作半径范围[Rfar,Rnear], 或工作距离范围[Zfar,Znear]。
本发明通过实现在本质上对于恒定总光功率的LED照明光源辐射系统的权重值再分配实现在对应的虹膜变焦聚焦光学成像系统的视场角范围[FOViris‐far,FOViris‐near],工作半径范围[Rfar,Rnear],或工作距离范围[Zfar,Znear]内等效拟合的响应于对应的LED照明光源辐射强度立体角。
∑WI*OPI=OP
OPi为具有不同的辐射方向角和辐射强度立体角的LED照明光源辐射系统的光学功率。
Wi为对应OPi的权重值。
i为具有不同的辐射方向角和辐射强度立体角的LED照明光源辐射系统的数量。
OP为LED照明光源辐射系统的恒定总光学功率。
根据本发明具体实施例,在i=2的实列,即在远端工作距离Zfar和近端工作距离Znear的不同辐射方向角和辐射强度立体角的LED照明光源辐射系统的光学功率OPfar和OPnear分配实现任意给定工作距离Z时对应的LED照明光源辐射强度立体角和恒定的总光功率OP的组合控制举例。
W1*OP1+W2*OP2=OP或Wfar*OPfar+Wnear*OPnear=OP
定义OP为工作距离Z对应的LED照明光源辐射系统的恒定总光学功率。
定义OPfar为远端工距离Zfar对应的LED照明光源辐射系统的光学功率。
Wfar为对应OPfar的权重值。
定义OPnear为近端工作距离Znear对应的近端LED照明光源辐射系统的光学功率。
Wnear为对应OPnear的权重值。
在Wfar+Wnear=1条件下,根据上述公式有以下推论:
Wfar=[cos 3(ψz)*Z 2-cos 3(ψnear)*Znear 2]/[cos 3(ψfar)*Zfar 2-cos 3(ψnear)*Znear 2]。
Wnear]=[cos 3(ψfar)*Zfar 2-cos 3(ψz)*Z 2] /[cos 3(ψfar)*Zfar 2-cos 3(ψnear)*Znear 2]。
其中,ψz为Z工作距离LED照明光源辐射系统的辐射方向角。
其中,ψfar为远端工作距离LED照明光源辐射系统的辐射方向角。
其中,ψnear为近端工作距离LED照明光源辐射系统的辐射方向角。
特别的,在cos 3(ψfar)/cos 3(ψz)=1和cos 3(ψnear)/cos 3(ψz)=1的简化条件下,上述公式简化为:
Wfar=[Z 2-Znear 2]/[Zfar 2-Znear 2]。
Wnear=[Zfar 2-Z 2]/[Zfar 2-Znear 2]。
通过组合控制分配权重值比例Wfar和Wnear在远端工作距离Zfar和近端工作距离Znear的不同辐射方向角和辐射强度立体角的LED照明光源辐射系统的光学功率OPfar和OPnear分配实现任意给定工作距离Z时对应的LED照明光源辐射强度立体角和恒定的总光功率。
根据本发明具体实施例,同样在i=2的实例,即在远端工作距离Zfar和近端工作距离Znear的不同辐射方向角和辐射强度立体角的LED照明光源辐射系统的光学功率OPfar和OPnear分配实现任意给定工作距离Z时对应的LED照明光源辐射强度立体角和恒定的总光功率OP的组合控制举例。
同时加入LED照明光源辐射系统的辐射强度归一化分布函数的边界条件f(Ω)far*Wfar*OPfar+f(Ω)near*Wnear*OPnear=f(Ω)z*OP。
定义OP为工作距离Z对应的LED照明光源辐射系统的恒定总光学功率,f(Ω)z为对应OP的辐射强度归一化分布函数。
定义OPfar为远端工作距离Zfar对应的LED照明光源辐射系统的光学功率。
Wfar为对应OPfar的权重值,f(Ω)far为对应OPfar的辐射强度归一化分布函数。
定义OPnear为近端工作距离Znear对应的近端LED照明光源辐射系统的光学功率。
Wnear为对应OPnear的权重值,f(Ω)near为对应的OPnear辐射强度归一化分布函数。
在Wfar+Wnear=1条件下,根据上述公式有以下推论:
Wfar=[cos 3(ψz)*f(Ω)z*Z 2-cos 3(ψnear)*f(Ω)near*Znear 2]/[cos 3(ψfar)*f(Ω)far*Zfar 2-cos 3(ψnear)*f(Ω)near*Znear 2]。
Wnear=[cos 3(ψfar)*f(Ω)far*Zfar 2-cos 3(ψz)*f(Ω)z*Z 2]/[cos 3(ψfar)*f(Ω)far*Zfar 2-cos 3(ψnear)*f(Ω)near*Znear 2]。
特别的在Ω=Ω(ω),Wfar+Wnear=1条件下,根据上述公式有以下推论:
Wfar=[cos 3(ψz)*f(Ω(ω))z*Z 2-cos 3(ψnear)*f(Ω(ω))near*Znear 2]/[cos 3(ψfar)*f(Ω(ω))far*Zfar 2-cos 3(ψnear)*f(Ω(ω))near*Znear 2]。
Wnear=[cos 3(ψfar)*f(Ω(ω))far*Zfar 2-cos 3(ψz)*f(Ω(ω))z*Z 2]/[cos 3(ψfar)*f(Ω(ω))far*Zfar 2-cos 3(ψnear)*f(Ω(ω))near*Znear 2]。
其中,ψz为Z工作距离LED照明光源辐射系统的辐射方向角。
其中,ψfar为远端工作距离LED照明光源辐射系统的辐射方向角。
其中,ψnear为近端工作距离LED照明光源辐射系统的辐射方向角。
其中,f(Ω(ω))z为Z工作距离LED照明光源辐射系统在Ω(ω)辐射强度立体角时对应的辐射强度归一化分布函数值。
其中,f(Ω(ω))far为远端工作距离LED照明光源辐射系统在Ω(ω)辐射强度立体角时对应的辐射强度归一化分布函数值。
其中,f(Ω(ω))near为近端工作距离LED照明光源辐射系统在Ω(ω)辐射强度立体角时对应的辐射强度归一化分布函数值。
特别的,在cos 3(ψfar)/cos 3(ψz)=1和cos 3(ψnear)/cos 3(ψz)=1的简化条件下,上述公式简化为:
Wfar=[f(Ω(ω))z*Z 2-f(Ω(ω))near*Znear 2]/[f(Ω(ω))far*Zfar 2-f(Ω(ω))near*Znear 2]
Wnear=[f(Ω(ω))far*Zfar 2-f(Ω(ω))z*Z 2]/[f(Ω(ω))far*Zfar 2-f(Ω(ω))near*Znear 2]
通过组合控制分配权重值比例Wfar和Wnear在远端工作距离Zfar和近端工作距离Znear的不同辐射方向角和辐射强度立体角的LED照明光源辐射系统的光学功率OPfar和OPnear分配实现任意给定工作距离Z时对应的LED照明光源辐射强度立体角和恒定的总光功率。
通过合成远端工作距离和近端工作距离对应的虹膜变焦聚焦光学成像系统的视场角范围内LED照明光源辐射强度立体角组合控制权重值再分配的光辐射功率等量的改变虹膜表面受辐射照度,根据公式保持接近 恒定,而且能完全匹配对应的虹膜光学变焦聚焦光学成像系统的视场角。
作为本发明的等同扩展,采用更多具有不同的辐射方向角和辐射强度立体角的LED照明光源辐射系统的光学功率组合控制应该被等同理解和等价。
本发明通过LED照明光源辐射系统和虹膜变焦聚焦光学成像系统被组合配置为具有响应于同步辐射强度方向角和辐射强度立体角的组合控制,实现LED照明光源辐射系统在不同3D物理空间点坐标响应于不同工作半径/距离对应的虹膜变焦聚焦光学成像系统的视场角之间对应匹配关系,在预定的工作视场和工作距离内满足恒定的成像图像亮度,恒定的成像图像相对照度,恒定的LED照明光源系统辐射光功率和恒定的眼睛虹膜受辐射照度。
为消除实际使用时使用者运动导致的运动模糊,归因于如此大的光学放大倍率,即使10cm/s以下的移动速度也能造成非常明显图像运动模糊干扰,导致影响影响识别性能。
本发明通过LED照明光源辐射系统和虹膜变焦聚焦光学成像系统被配置为同步脉冲外触发或同步脉冲内触发方式的全局像素曝光(积分)和照明辐射组合成像模式。
其中,同步脉冲曝光(积分)时间和同步脉冲照明辐射时间Tpulse<m/(PR*speed),speed为预定控制的运动速度如1m/s,m为预定控制的运动模糊图像像素尺度,m<10pxiels。
同步脉冲曝光(积分)频率和同步脉冲照明辐射频率Fpulse,Fpulse=[10,30]Hz,LED照明光源辐射系统产生同步脉冲照明辐射在虹膜表面的受辐射照度Tpulse*Fpulse*Eiris(ω)<10mw/cm2,以保证满足眼睛辐射生物安全。
更进一步,虹膜变焦聚焦光学成像系统在滤光片的结合下实现同步脉冲外触发或同步脉冲内触发方式的全局像素曝光(积分)和照明辐射组合成像模式可具有对外界不受控环境下对各种光干扰条件抗干扰性能。如高达10,000lux以上的户外太阳环境。
本发明所述超高分辨率图像成像传感器至少8K分辨率,既8000*4000 分辨率以上,考虑到如此超高分辨率带宽和帧率受限,本发明在图像质量处理时可采用binning或subsampling成像模式提高图像成像质量预处理速度。
归因于图像成像传感器不能无限增加分辨率,更近一步扩展视场角,本发明采用多组虹膜变焦聚焦光学成像系统阵列实现对应组数倍提高视场角。可以等价的理解扩展为相应倍数的分辨率对应的视场角。
保护窗口123可采用全透射钢化光学玻璃,或更优选的采用反射700nm以下可见光,透射700‐900nm红外光的滤光片,具有即能保护内部光学组件同时使用者无法观察到内部结构通过反射可见光提供使用者自然状态的使用视觉反馈效果,更进一步,过滤可见光可以提高虹膜变焦聚焦光学成像系统消除对外界非成像波长杂散光的干扰,进一步提高成像质量信噪比SNR。
本发明提供的一种远距离大视场虹膜光学成像的装置及方法,同时实现大范围时视场角和辐射照度恒定。
结合这里披露的本发明的说明和实践,本发明的其他实施例对于本领域技术人员都是易于想到和理解的。说明和实施例仅被认为是示例性的,本发明的真正范围和主旨均由权利要求所限定。

Claims (10)

  1. 一种远距离大视场虹膜光学成像的装置,其特征在于,所述装置包括:
    虹膜光学跟踪系统,虹膜变焦聚焦光学成像系统,LED照明光源辐射系统,图像显示反馈系统,图像处理和驱动控制系统;
    所述虹膜光学跟踪系统包括3D深度成像单元,用于执行3D物理空间点坐标获取;
    所述的虹膜变焦聚焦光学成像系统包括光学变焦聚焦透镜组和超高分辨率图像成像传感器,用于根据3D物理空间点坐标执行虹膜成像的焦距和聚焦位置调整,超高分辨率图像成像传感器物理成像;
    所述LED照明光源辐射系统包括辐射强度立体角和/或辐射强度方向角,用于根据3D物理空间点坐标执行响应于不同工作距离对应的虹膜变焦聚焦光学成像系统的视场角之间匹配关系的组合控制;
    所述的图像显示反馈系统包括显示屏用于实时显示当前图像和/或状态信息;
    所述3D深度成像单元成像视场角大于等于虹膜变焦聚焦光学成像系统的成像视场角;
    所述的图像处理和驱动控制系统连接虹膜光学跟踪系统,虹膜变焦聚焦光学成像系统,LED照明光源辐射系统,图像显示反馈系统,并实现各系统单元间的驱动和反馈控制。
  2. 根据权利要求1所述的装置,其特征在于,所述3D深度成像单元包括采用3D TOF深度成像或结构光深度成像,或双目立体视觉成像。
  3. 根据权利要求1所述的装置,其特征在于,所述超高分辨率图像成像传感器至少8K分辨率。
  4. 根据权利要求1所述的装置,其特征在于,所述LED照明光源辐射系统的辐射强度方向角度,满足关系:ψ=arctan(D/Z),其中,
    定义在LED照明光源辐射系统的辐射强度峰值方向对应的中心线和虹膜变焦聚焦光学成像系统的光轴间夹角,D为LED照明光源辐射系统的 光学中心和虹膜变焦聚焦光学成像系统光学中心的距离,Z为虹膜变焦聚焦光学成像系统的工作距离。
  5. 根据权利要求1所述的装置,其特征在于,所述LED照明光源辐射系统的辐射强度立体角,满足关系:Ω(ω)=4π*sin 2(ω)单位球面度sr,其中,
    ω=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/((1+β)*EFLiris))=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/(β*Z)),ω为虹膜变焦聚焦光学成像系统的半视场角,
    PXiris为虹膜变焦聚焦光学成像系统的X水平方向像素分辨率,
    PYiris为虹膜变焦聚焦光学成像系统的Y垂直方向像素分辨率,
    EFLiris为焦距位置,
    β=PR*PSiris,PR为虹膜物理直径像方分辨率,
    PSiris为虹膜变焦聚焦光学成像系统的超高分辨率图像成像传感器的像素单位分辨率,
    Z为虹膜变焦聚焦光学成像系统的工作距离。
  6. 根据权利要求1所述的装置,其特征在于,所述LED照明光源辐射系统和虹膜变焦聚焦光学成像系统被配置为:
    在滤光片的结合下同步脉冲外触发或同步脉冲内触发方式的全局像素曝光(积分)和照明辐射的组合成像模式,其中:
    所述的组合成像模式的同步脉冲曝光(积分)时间和同步脉冲照明辐射时间Tpulse<m/(PR*speed),
    speed为预定控制的运动速度,单位m/s,
    PR为虹膜物理直径像方分辨率,
    m为预定控制的运动模糊图像像素尺度,单位pixel;
    所述的组合成像模式的同步脉冲曝光(积分)频率和同步脉冲照明辐射频率Fpulse,所述同步脉冲照明辐射频率Fpulse=[10,30]Hz,
    所述LED照明光源辐射系统产生同步脉冲照明辐射在虹膜表面的受辐射照度Tpulse*Fpulse*Eiris(ω)<10mw/cm 2
    Eiris(ω)为虹膜表面上受辐射照度。
  7. 一种远距离大视场虹膜光学成像的方法,其特征在于,所述方法包括:
    图像处理和驱动控制系统执行虹膜光学跟踪系统,虹膜变焦聚焦光学成像系统,LED照明光源辐射系统,图像显示反馈系统之间的驱动和反馈控制过程:
    a、反馈控制虹膜光学跟踪系统,通过虹膜光学跟踪系统的3D深度成像单元获取虹膜关键点3D坐标,转换相对坐标为3D物理空间点,实现实时同步虹膜光学成像跟踪;
    b、反馈控制虹膜变焦聚焦光学成像系统,根据3D物理空间点坐标,实现实时同步光学变焦聚焦透镜组的焦距和/或聚焦位置的反馈控制,超高分辨率图像成像传感器物理成像的反馈控制;
    c、反馈控制LED照明光源辐射系统,根据3D物理空间点坐标,实现实时同步响应于不同工作距离对应的虹膜变焦聚焦光学成像系统的视场角之间匹配关系的LED照明光源辐射强度方向角度和/或LED照明光源辐射强度立体角的反馈控制;
    d、反馈控制图像显示反馈系统实时显示当前图像和/或状态信息;
    所述图像显示反馈系统实现实时同步显示当前图像为3D深度成像单元成像的红外图像,RGB可见光单元成像图像或虹膜变焦聚焦光学成像图像。
  8. 根据权利要求7所述的方法,其特征在于,反馈控制虹膜成像跟踪系统,包括:
    a1、根据预定的工作视场范围FOV,定义3D深度成像单元的视场角FOVface和有效成像焦距EFLface:
    EFLface=[(PXface 2+PYface 2) 1/2*PSface/2]/tan(FOVface/2)
    PXface为3D深度成像单元的X水平方向像素分辨率;
    PYface为3D深度成像单元的Y垂直方向像素分辨率;
    PSface为3D深度成像单元的像素单位分辨率;
    FOVface为3D深度成像单元的视场角度,FOVface=FOV;
    EFLface为3D深度成像单元的有效成像焦距。
    a2、定义3D深度成像单元控制获取虹膜关键点:
    a21、获取3D深度成像单元的亮度(红外灰度阶)图像Ii(x,y)和深度距离图像Iz(x,y);
    a22、在亮度图像Ii(x,y)中检测人脸区域,在人脸区域进一步定位左右眼中心坐标(xl,yl)和(xr,yr);
    a23、获取在深度距离图像Iz(x,y)中左右眼中心对应坐标的位置的深度距离信息,
    z=[Iz(xl,yl)+lz(xr,yr)]/2或
    z=Iz((xl+xr)/2,(yl+yr)/2);
    a24、产生3D深度成像单元像方关键参考点,
    KPface(xe,ye,z):KPface(xe,ye,z)=KPface((xl+xr-PXface)/2*PSface,(yl+yr-PYface)/2*PSface,z);
    a25、产生3D深度成像单元物方关键参考点KPface(Xe,Ye,Ze):KPface(Xe,Ye,Ze)=KPface(xe*z/EFLface,ye*z/EFLface,z)。
    a3、建立3D深度成像单元的物方关键参考点坐标KPface(Xe,Xe,Ze)相对虹膜变焦聚焦光学成像系统的3D物理空间点Piris(X,Y,Z)坐标变换,Piris(X,Y,Z)=(Xe-Xoffset,Xe-Yoffset,Ze-Zoffset),
    (Xoffset,Yoffset,Zoffset)为3D深度成像单元相对虹膜变焦聚焦光学成像系统的3D物理位置坐标偏移。
  9. 根据权利要求7所述的方法,其特征在于,反馈控制虹膜变焦聚焦光学成像系统,包括:
    b1、执行虹膜变焦聚焦光学成像系统的变焦聚焦参数同步控制;
    b11、执行对虹膜变焦聚焦光学成像系统的焦距参数控制,实现焦距位置保持恒定的预定放大倍率即相同成像虹膜直径,
    焦距位置EFLiris=Z*β/(1+β),
    其中,β=PR*PSiris,PR为虹膜物理直径像方分辨率,
    PSiris虹膜变焦聚焦光学成像系统的图像成像传感器的像素单位分 辨率,
    Z为虹膜变焦聚焦光学成像系统的工作距离;
    b2、执行对虹膜变焦聚焦光学成像系统的聚焦参数控制,实现聚焦位置在像方景深范围内,
    聚焦位置FOCUS=β*[Z-kDOF,Z+kDOF],
    其中,k步数控制范围,DOF=2*FNO*SOC*(1+β)/β 2,其中,FNO为虹膜变焦聚焦光学成像系统的光圈参数,
    SOC为为虹膜变焦聚焦光学成像系统的最小物理光斑分辨率参数。
  10. 根据权利要求7所述方法,其特征在于,所述反馈控制LED照明光源辐射系统,包括:
    c1、执行LED照明光源辐射系统的照明光源辐射强度方向角度参数控制,
    LED照明光源辐射方向角度ψ=arctan(D/Z),
    定义在LED照明光源辐射系统的辐射强度峰值方向对应的中心线和虹膜变焦聚焦光学成像系统的光轴间夹角,D为LED照明光源辐射系统的光学中心和虹膜变焦聚焦光学成像系统光学中心的距离,Z为虹膜变焦聚焦光学成像系统的工作距离;
    c2、执行对LED照明光源辐射系统的LED照明光源辐射强度立体角的参数控制,
    LED照明光源辐射强度立体角Ω(ω)=4π*sin 2(ω)单位球面度sr,其中,
    ω=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/((1+β)*EFLiris))=arctan((PXiris 2+PYiris 2) 1/2/2*PSiris/(β*Z)),ω为虹膜变焦聚焦光学成像系统的半视场角,
    PXiris为虹膜变焦聚焦光学成像系统的X水平方向像素分辨率,
    PYiris为虹膜变焦聚焦光学成像系统的Y垂直方向像素分辨率,
    EFLiris为焦距位置,
    β=PR*PSiris,PR为虹膜物理直径像方分辨率,
    PSiris为虹膜变焦聚焦光学成像系统的超高分辨率图像成像传感器 的像素单位分辨率,
    Z为虹膜变焦聚焦光学成像系统的工作距离。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115113308A (zh) * 2022-07-06 2022-09-27 重庆大学 一种具有角放大功能的超分辨成像透镜

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6714665B1 (en) * 1994-09-02 2004-03-30 Sarnoff Corporation Fully automated iris recognition system utilizing wide and narrow fields of view
CN101770573A (zh) * 2010-01-14 2010-07-07 沈洪泉 用于虹膜识别的自动聚焦虹膜图像成像装置及其控制方法
CN102831392A (zh) * 2012-07-09 2012-12-19 哈尔滨工业大学 一种远距离虹膜跟踪与采集装置及其方法
CN102855471A (zh) * 2012-08-01 2013-01-02 中国科学院自动化研究所 远距离虹膜智能成像装置及方法
CN106022299A (zh) * 2016-06-01 2016-10-12 北京天诚盛业科技有限公司 一种具有补光功能的虹膜识别装置、识别方法和补光方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7095901B2 (en) * 2001-03-15 2006-08-22 Lg Electronics, Inc. Apparatus and method for adjusting focus position in iris recognition system
CN106295471A (zh) * 2015-05-24 2017-01-04 江西恒盛晶微技术有限公司 一种基于dsp的嵌入式生物特征信息采集系统
CN105554385B (zh) * 2015-12-18 2018-07-10 天津中科智能识别产业技术研究院有限公司 一种远距离多模态生物特征识别方法及其系统
WO2018000020A1 (en) * 2016-06-29 2018-01-04 Seeing Machines Limited Systems and methods for performing eye gaze tracking
KR102587237B1 (ko) * 2016-07-25 2023-10-11 엘지이노텍 주식회사 홍채 인식용 적외선 발광 장치

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6714665B1 (en) * 1994-09-02 2004-03-30 Sarnoff Corporation Fully automated iris recognition system utilizing wide and narrow fields of view
CN101770573A (zh) * 2010-01-14 2010-07-07 沈洪泉 用于虹膜识别的自动聚焦虹膜图像成像装置及其控制方法
CN102831392A (zh) * 2012-07-09 2012-12-19 哈尔滨工业大学 一种远距离虹膜跟踪与采集装置及其方法
CN102855471A (zh) * 2012-08-01 2013-01-02 中国科学院自动化研究所 远距离虹膜智能成像装置及方法
CN106022299A (zh) * 2016-06-01 2016-10-12 北京天诚盛业科技有限公司 一种具有补光功能的虹膜识别装置、识别方法和补光方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115113308A (zh) * 2022-07-06 2022-09-27 重庆大学 一种具有角放大功能的超分辨成像透镜
CN115113308B (zh) * 2022-07-06 2024-05-14 重庆大学 一种具有角放大功能的超分辨成像透镜

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