U.S. patent application number 11/573550 was filed with the patent office on 2009-07-16 for device for contactlessly controlling the surface profile of objects.
Invention is credited to Andrey Klimov, Sergey Suhovey, Artem Yukhin.
Application Number | 20090179996 11/573550 |
Document ID | / |
Family ID | 36060302 |
Filed Date | 2009-07-16 |
United States Patent
Application |
20090179996 |
Kind Code |
A2 |
Klimov; Andrey ; et
al. |
July 16, 2009 |
DEVICE FOR CONTACTLESSLY CONTROLLING THE SURFACE PROFILE OF
OBJECTS
Abstract
The invention relates to the devices for contactlessly measuring
surface profiles and can be used for person identification in
security systems. The inventive device for contactlessly
controlling surface profile comprises a pulse illumination unit
which is provided with a transparency and forms a transparency
image on an object surface, and image recording unit and a
computer. Said device also comprises a control unit which is
connected to the image recording unit in the form of a TV camera
with field interlacing, the pulse illumination unit and to the
computer for synchronizing the illumination of the object surface
by said pulse illumination unit with the TV camera field and for
synchronizing the image processing by the computer with the TV
interlacing. The transparency is embodied in the form of a line
screen provided with an aperiodical different width band structure
and a uniform transmission along each band, thereby making it
possible to identify the sequence of the line screen images on the
object surface.
Inventors: |
Klimov; Andrey; (Moscow,
RU) ; Suhovey; Sergey; (Moscow, RU) ; Yukhin;
Artem; (Moscow, RU) |
Correspondence
Address: |
FENWICK & WEST LLP
SILICON VALLEY CENTER
801 CALIFORNIA STREET
MOUNTAIN VIEW
CA
94041
UNITED STATES
650-988-8500
650-938-5200
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20080266409 A1 |
October 30, 2008 |
|
|
Family ID: |
36060302 |
Appl. No.: |
11/573550 |
Filed: |
January 15, 2008 |
Current U.S.
Class: |
348/222.1;
348/E5.031 |
Current CPC
Class: |
G01B 11/254
20130101 |
Class at
Publication: |
348/222.1;
348/E05.031 |
International
Class: |
H04N 5/228 20060101
H04N005/228 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 12, 2004 |
RU |
PCT/RU2004/000315 |
Claims
1. A device for contactlessly controlling surface profile of
objects comprising a pulse illumination unit provided with a pulse
light source and a transparency, which forms a transparency image
on an object surface, an image recording unit and a computer,
provided that the operation of the pulse illumination unit is
synchronized with the operation of the image recording unit,
wherein included additionally is a control unit, which is connected
to the image recording unit realized in the form of a TV camera
with field interlacing, to the pulse illumination unit and to the
computer for synchronizing illumination of the object surface using
a pulse illumination unit with the TV camera half-field and for
synchronizing image processing by the computer with a TV camera
field sweep.
2. A device according to claim 1, wherein a transparency is
realized in the form of a line screen with aperiodic structure of
the variable width bands and uniform transmission along each band,
thereby making it possible to identify a sequence of the line
screen images on the object surface.
3. A device according to claim 1, wherein a TV camera is realized
to allow variation in field sweep frequency.
Description
[0001] This application is the National Stage of International
Application No. PCT/RU2005/000160, published in Russian under PCT
Article 21(2), filed Apr. 1, 2005, which claims priority to
International Application No. PCT/RU2004/00315, filed Aug. 12,
2004, both of which are incorporated by reference in their
entirety.
FIELD OF ENGINEERING THE INVENTION RELATES TO
[0002] The invention relates to the devices for contactlessly
measuring surface profiles and can be used for person
identification in security systems.
STATE OF THE ART
[0003] A device for contactless control of the surface profile of
objects is known, WO 00/70303 of 23 Nov. 2000, comprising of a
pulse illumination unit provided with a pulse light source and a
transparency, which forms a transparency image on an object
surface, an image recording unit and a computer, wherein the
operation of the pulse illumination unit is synchronized with the
operation of the image recording unit.
[0004] The disadvantage of this device lies in its inability to
contactlessly control surface profiles of moving objects, when it
is required to minimize the shift of the transparency image,
recorded in the image recording unit, with respect to the
corresponding image of the object surface, and a "smear" of images
recorded in the recording unit. Besides, this device does not allow
controlling the object surface profiles, which randomly appear for
a short time in the field of view of the image recording unit.
INVENTION DISCLOSURE
[0005] The invention is aimed at providing a contactless control of
the surface profiles of moving objects, which randomly appear and
disappear in the field of view of the device.
[0006] A technical result of utilization of this invention is a
periodicity of controlling the surface profile of a moving object
as well as increase in control rate and accuracy. This also enables
a maximum frequency of controlling the surface profile of a moving
object--the field sweep frequency of a TV camera.
[0007] Described technical result is achieved by means of a device
for contactless control of the surface profile of objects
comprising a pulse illumination unit provided with a pulse light
source and a transparency, which forms a transparency image on an
object surface; an image recording unit and a computer; and
additionally comprising of a control unit, which is connected to
the image recording unit realized in the form of a TV camera with
field interlacing, to the pulse illumination unit and to the
computer for synchronizing the illumination of the object surface
by said pulse illumination unit with the TV camera field and for
synchronizing the image processing by the computer with TV camera
interlacing.
[0008] In this case, the transparency of the pulse illumination
unit can be realized to enable computer to recognize positions of
images of its elements on the object surface. This allows for
computer compensation for the decline in band image quality due to
field interlacing.
[0009] The transparency can be realized in the form of a line
screen provided with an aperiodic different width band structure
and a uniform transmission along each band, thereby making it
possible to identify the line screen images on the object
surface.
[0010] TV camera can be realized with provided capability of
changing the field sweep frequency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a schematic of the device for contactless
control of the surface profile of objects.
[0012] FIG. 2 shows transparency and its image distorted by the
surface profile.
BEST EMBODIMENT
[0013] According to the schematic of the device for contactless
control of the surface profile of objects shown in FIG. 1, this
device comprises a pulse illumination block, which consists of a
pulse light source 1, condenser 2, transparency 3 and projection
lenses 4, TV camera 5, computer 6 and control unit 7. Control unit
7 is connected to the pulse light source 1, TV camera 5 and
computer 6.
[0014] Optical axes of the projection lenses 4 and those of the TV
camera 5 are positioned at an angle .alpha. with respect to each
other. The image of the transparency 4 distorted by the surface
profile of an object, for example, human face, is recorded by the
TV camera and transmitted to the computer 6, which computes the
height Z of the surface profile for a point with coordinates X,Y
using the formula: Z=.DELTA.Y/tan(.alpha.), where .DELTA.Y is a
measure of image band distortion of the transparency 4 shown in
FIG. 2.
[0015] TV camera 5 is chosen to have field interlacing, i.e. the
first half of the field is recorded with an interval between lines,
and the second--also with interval between the lines of the field
sweep, but with a shift with respect to the lines of the first half
of the field.
[0016] During the time of full field recording, the recording unit
records the transparency image during the first half-field. To
achieve this, the control unit 7 along with the pulse illumination
unit and TV camera synchronizes the illumination pulse from the
pulse light source 1 with the first half of the field. During the
second half of the field, the surface image of an object
illuminated with some additional light source (natural or
artificial) is recorded. An essential moment is the use of TV
camera with field interlacing in combination with pulse
illumination unit to record the transparency image, which enables
high processing rate.
[0017] The control unit 7 synchronizes the time of image processing
by the computer 6 with the field sweep frequency of TV camera 5.
The field sweep frequency is chosen based on anticipated movement
rate of an object.
[0018] Realizing transparency 3 in the form of a linear pattern
with aperiodic structure (not shown in FIG. 2) enables improved
accuracy of determining the width of the band image, since relative
variation of the bands in the transparency is known. Presence of
variable width bands positioned aperiodically with respect to each
other provides higher accuracy detection of their distortion
orthogonally to the band direction over short period of time.
* * * * *