CN-121977795-A - Device and method for detecting imaging resolution of drilling video

Abstract

The invention provides a device and a method for detecting imaging resolution of a drilling video, which relate to the technical field of optical measurement, wherein the device comprises a transparent pressure-resistant window with a composite target inside, a coaxial programmable lighting assembly, an IMU, an environment sensor, an imaging assembly and a control processing unit; the method comprises the steps of synchronously collecting composite target image data, IMU data and environment sensing data, performing time alignment on the data, calculating and measuring an MTF curve, a motion MTF, a medium MTF and a pixel caliber MTF based on the composite target image, the IMU data, the environment sensing data and an image obtained by an imaging component, stripping the motion MTF, the medium MTF and the pixel caliber MTF from the measured MTF curve to obtain an optical intrinsic MTF, and detecting the imaging resolution of the drilling video according to the measured MTF and the optical intrinsic MTF. The invention realizes the determination of the effective resolution and the intrinsic optical resolution of the video imaging while drilling under the complex working condition.

Inventors

• JIAO YUYONG
• DANG WENGANG
• DUAN HONGFEI
• WANG YUANQING
• HUANG LINCHONG
• LIU JIAN
• REN JIE
• WU WENAN
• SHENG MINGHONG
• ZHENG FEI
• YAN XUEFENG
• GUO YONGGANG
• XUE YIGUO
• JIA LIANHUI

Assignees

• 中山大学
• 中铁工程装备集团有限公司
• 中国地质大学（武汉）
• 中铁十一局集团有限公司
• 山东能源集团有限公司
• 安徽建工建设投资集团有限公司
• 中国地质大学（北京）
• 武汉市汉阳市政建设集团有限公司

Dates

Publication Date

20260505

Application Date

20251218

Claims (8)

1. 1. An apparatus for detecting imaging resolution of video-on-drill, comprising: the system comprises a transparent pressure-resistant window with a composite target inside, a coaxial programmable lighting assembly, an IMU, an environment sensor, an interface module, an imaging assembly and a control processing unit; The environment sensor comprises a turbidity/transmittance sensor, an illuminance sensor, a temperature sensor and a pressure sensor; the composite target is a concentric multi-ring composite target, the outer ring is a bevel edge target, the middle ring is a Siemens star target, the inner ring is a circular observation imaging area, an annular isolation area is arranged between the middle ring and the outer ring, an XOY pixel shaft is built by taking the center of the inner ring as an origin, four bevel edge strings are arranged on the outer ring, two endpoints of the bevel edge strings are arranged on the outer circle of the outer ring, perpendicular line sections of the bevel edge strings are made from the origin, the perpendicular line sections meet that the lengths of the four perpendicular line sections are equal, and the directions of the four perpendicular line sections are respectively clockwise rotation of an X-axis positive direction, an X-axis negative direction, a Y-axis positive direction and a Y-axis negative direction The number of Siemens star sectors is 24-72; the in-line programmable lighting assembly is used for providing controllable lighting; the interface module is used for power supply and data transmission; IMU data, environment sensing data, images obtained by the imaging component and the composite target image are processed by the control processing unit to obtain imaging resolution.
2. 2. A method for detecting imaging resolution of video-on-drill in accordance with claim 1, wherein said method is implemented based on said one means for detecting imaging resolution of video-on-drill, said method comprising: s1, synchronously acquiring composite target image data, IMU data and environment sensing data, and performing time alignment on the data; S2, calculating and measuring an MTF curve based on the composite target image; reconstructing an image plane track based on IMU data and calculating a motion MTF; establishing a media MTF based on the environmental sensing data; establishing a pixel aperture MTF based on an image obtained by the imaging assembly; S3, stripping the motion MTF, the medium MTF and the pixel caliber MTF from the measured MTF curve to obtain an optical intrinsic MTF; S4, detecting the imaging resolution of the drilling video according to the measured MTF and the optical intrinsic MTF.
3. 3. A method for detecting imaging resolution of video-on-drill according to claim 1, wherein the measured MTF using siemens star targets is formulated as: Wherein, the Indicating radial frequency as The measured MTF at the time of this, The circumference representing the radius r corresponds to the radial frequency, The polar radius of the ring is measured for the star symbol, And The inner circle radius and the outer circle radius of the middle ring where the Siemens are positioned are respectively, Representing a phase-locked cosine component, Indicating the circumference of radius r at an angle The gray level at which the color is changed, Represents the circumferential angle, M represents the black-and-white logarithm of Siemens star targets, The degree of modulation is indicated as being, Representing a phase-locked sinusoidal component, Represents the average luminance over the circumference of radius r.
4. 4. A method for detecting imaging resolution of video-on-drill in accordance with claim 1, wherein the measured MTF based on hypotenuse target using SFR hypotenuse method is given by: Wherein, the Indicating direction Is used for the measurement of the MTF, Represents the kth spatial frequency, k represents the frequency index, Representing a discrete spectrum of frequencies, Representing the fourier transform of the signal, Represents a windowed line spread function, N represents the number of sampling points, The normal binning step size is indicated, Representing the SFR oversampling factor, p representing the pixel pitch, The window function is represented by a function of the window, The line spread function is represented as a function of the line spread, Representing the average gray level per bin of the edge spread function, Representing the set of pixel indices contained in the nth bin, The pixel(s) of the i-th pixel is indicated, Representing the one-dimensional coordinates of the i-th pixel center to the direction of the hypotenuse normal, Representing the coordinates of the center of the i-th pixel, Representing the signed vertical distance from the origin to the hypotenuse.
5. 5. A method for detecting imaging resolution of video-on-drill in accordance with claim 1, wherein the motion MTF is formulated as: Wherein, the Representing the motion MTF at a frequency f, Indicating the exposure time, i indicating the imaginary unit, The equivalent trajectory of the image plane at t is represented, Representing the initial image shift, t representing time, Representing the image plane at Instantaneous speed at that time.
6. 6. A method for detecting imaging resolution of video-on-drill in accordance with claim 1, wherein the medium MTF is formulated as: Wherein, the Represents the medium MTF at a frequency f, Represents the standard deviation of the equivalent scattering, And Representing the fitting coefficients, NTU representing turbidity, Indicating the effective optical path.
7. 7. A method for detecting imaging resolution of video-on-drill in accordance with claim 1, wherein the pixel aperture MTF is formulated as: Wherein, the Representation of At the pixel aperture MTF of the pixel, Representing the two components of the image plane two-dimensional spatial frequency vector f in the x-axis and the y-axis, and p represents the pixel size.
8. 8.A method for detecting imaging resolution of video-on-drill in accordance with claim 1, wherein the optical intrinsic MTF is formulated as: Wherein, the Indicating the optical intrinsic MTF at the compensated frequency f, Represents the measured MTF at frequency f, Represents the medium MTF at the compensated frequency f, Representing the motion MTF at the compensated frequency f, The pixel aperture MTF at frequency f is shown.

Description

Device and method for detecting imaging resolution of drilling video Technical Field The invention relates to the technical field of optical measurement, in particular to a device and a method for detecting imaging resolution of a drilling video. Background The video while drilling is used for structure identification and risk assessment of scenes such as geothermal, oil gas, mines, urban underground spaces and the like. The working conditions are common high-speed rotation, strong vibration, turbidity/absorption, high temperature, high pressure, weak light and the like. The traditional resolution detection is mostly carried out in static cleaning media, the obtained index is difficult to represent the effective resolution in the field, and a means for separating motion blur and media scattering/absorption from total degradation is lacked, so that performance bottlenecks cannot be positioned and an optimized path is given. ISO 12233 hypotenuse methods, USAF targets, and the like have limited applicability in strongly rotating and turbid environments, and in-situ quality control and consistency calibration remain challenging. Disclosure of Invention The invention aims to solve the problem that effective resolution and intrinsic optical resolution of drilling video imaging are difficult to measure under the working conditions of rotation, vibration and turbid medium, and provides a method and a device for detecting the imaging resolution of the drilling video, wherein the device comprises the following steps: the system comprises a transparent pressure-resistant window with a composite target inside, a coaxial programmable lighting assembly, an IMU, an environment sensor, an interface module, an imaging assembly and a control processing unit; The environment sensor comprises a turbidity/transmittance sensor, an illuminance sensor, a temperature sensor and a pressure sensor; the composite target is a concentric multi-ring composite target, the outer ring is a bevel edge target, the middle ring is a Siemens star target, the inner ring is a circular observation imaging area, an annular isolation area is arranged between the middle ring and the outer ring, an XOY pixel shaft is built by taking the center of the inner ring as an origin, four bevel edge strings are arranged on the outer ring, two endpoints of the bevel edge strings are arranged on the outer circle of the outer ring, perpendicular line sections of the bevel edge strings are made from the origin, the perpendicular line sections meet that the lengths of the four perpendicular line sections are equal, and the directions of the four perpendicular line sections are respectively clockwise rotation of an X-axis positive direction, an X-axis negative direction, a Y-axis positive direction and a Y-axis negative direction The number of Siemens star sectors is 24-72; the in-line programmable lighting assembly is used for providing controllable lighting; the interface module is used for power supply and data transmission; IMU data, environment sensing data, images obtained by the imaging component and the composite target image are processed by the control processing unit to obtain imaging resolution. The invention also provides a method for detecting the imaging resolution of the drilling video, which is realized based on the device for detecting the imaging resolution of the drilling video, and comprises the following steps: s1, synchronously acquiring composite target image data, IMU data and environment sensing data, and performing time alignment on the data; S2, calculating and measuring an MTF curve based on the composite target image; reconstructing an image plane track based on IMU data and calculating a motion MTF; establishing a media MTF based on the environmental sensing data; establishing a pixel aperture MTF based on an image obtained by the imaging assembly; S3, stripping the motion MTF, the medium MTF and the pixel caliber MTF from the measured MTF curve to obtain an optical intrinsic MTF; S4, detecting the imaging resolution of the drilling video according to the measured MTF and the optical intrinsic MTF. Further, the formula of the measured MTF using the siemens star target is: Wherein, the Indicating radial frequency asThe measured MTF at the time of this,The circumference representing the radius r corresponds to the radial frequency,The polar radius of the ring is measured for the star symbol,AndThe inner circle radius and the outer circle radius of the middle ring where the Siemens are positioned are respectively,Representing a phase-locked cosine component,Indicating the circumference of radius r at an angleThe gray level at which the color is changed,Represents the circumferential angle, M represents the black-and-white logarithm of Siemens star targets,The degree of modulation is indicated as being,Representing a phase-locked sinusoidal component,Represents the average luminance over the circumference of radius r. Further, the measured