CN-122004742-A - OCT retina partition brightness self-adaptive clear imaging adjustment method and system

CN122004742ACN 122004742 ACN122004742 ACN 122004742ACN-122004742-A

Abstract

The invention belongs to the technical field of OCT imaging, and particularly relates to an OCT retina partition brightness self-adaptive clear imaging adjusting method and system. The method comprises the steps of determining five areas in the center and four corners of an OCT retina image, extracting brightness characteristics of the five areas, determining the relative positions of OCT retina image light spots and pupils based on the relation between the brightness characteristics of the five areas and a preset threshold value, constructing a corresponding error function according to the relative positions of the OCT retina image light spots and the pupils, and adjusting the positions of the light spots by adopting a PID control method. The brightness characteristic analysis dimension initiates a center+four-quadrant partition statistics combined weighted average algorithm, judges pupil alignment degree according to light spot state classification, provides accurate basis for dynamic adjustment, balances adjustment response speed and stability by introducing error functions of proportion compensation and differential control, and improves adjustment efficiency and imaging quality stability by means of pupil position prejudgment+reverse adjustment logic.

Inventors

SONG WEIYE
ZHOU LIBO
CUI YUAN
QI MIN
Yan Bingcan
CHEN SHUJIANG
WANG YUKUAN
Yao Zhengkai
YANG HAOHUA
LIU ENYU
ZHAO YIXIANG
XU GUODONG

Assignees

山东大学

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (15)

The OCT retina partition brightness self-adaptive clear imaging adjustment method is characterized by comprising the following steps of: acquiring an OCT retina image, and determining five areas in the center and four corners of the OCT retina image; extracting brightness characteristics of five areas, including average brightness of a central area, average brightness of four corners, overall average brightness, average brightness of four corners and relative center ratio of four corners; determining the relative position of OCT retina image facula and pupil based on the relation between the brightness characteristics of the five areas and a preset threshold value; And constructing a corresponding error function according to the relative positions of the OCT retina image facula and the pupil, tracking target brightness values of the five areas by adopting a PID control method, and realizing the adjustment of the position of the facula so as to enable OCT retina imaging to reach preset definition.
2. The OCT retinal partitioning luminance adaptive clear imaging adjustment method of claim 1, wherein the four corner regions are regions of four corners of the OCT retinal image, upper left, upper right, lower left, and lower right.
3. The OCT retinal partitioning luminance adaptive clear imaging adjustment method of claim 2, wherein: calculating the average value of the pixel brightness of the central area to obtain the average brightness of the central area; and calculating the average value of the pixel brightness of the four-corner area to obtain the average brightness of the four-corner area.
4. The OCT retinal partitioning luminance adaptive clear imaging adjustment method of claim 2, wherein the central region average luminance is calculated as: ; The average brightness of the four corner areas is calculated by the following specific formula: ; Wherein, the Average brightness for the central region; Is the average brightness of the four-corner area, For the sequence number of the four corner sub-areas, The values are 1,2,3 or 4, and correspond to the four sub-areas of the upper left corner, the upper right corner, the lower left corner and the lower right corner respectively; indicating the average luminance of the upper left corner region, Indicating the average luminance in the upper right corner region, Indicating the average luminance in the lower left corner region, Representing the average brightness in the lower right corner region; For the pixel brightness of the corresponding region, The coordinates of the pixels are represented and, The abscissa of the pixel is indicated and, Representing the pixel ordinate; Representing a central region; Representing four corner sub-regions, Representing the upper left corner sub-region, Representing the upper right hand corner sub-region, Representing the lower left corner sub-region, Representing the lower right corner subregion; representing averaging.
5. The OCT retinal partitioning luminance adaptive clear imaging adjustment method of claim 4, wherein: Calculating global average brightness by combining weighted averages of the average brightness of the central area and the average brightness of the four corner areas; setting a brightness difference normalization term of the center and the corner, and calculating the average brightness of four corners through weighting the brightness difference normalization term of the center and the corner; and calculating the relative center ratio of the four corners by combining the average brightness of the central area and the average brightness of the four corners by the ratio of the average brightness of the four corners to the average brightness of the central area and the average brightness of the four corners.
6. The OCT retinal partitioning luminance adaptive clear imaging adjustment method of claim 4, wherein the global average luminance is calculated as: ; the average brightness of four corners is as follows: ; ratio of four corners to center: ; Wherein, the Representing a global average luminance; Represents the average brightness of four corners; representing the relative center ratio of four corners; Is a preset positive value.
7. The OCT retinal partitioning luminance adaptive clear imaging adjustment method of claim 6, wherein determining the relative position of the OCT retinal image spot and the pupil based on the relationship between the luminance characteristics of the five regions and a preset threshold value, specifically comprises: two types of threshold values are preset, namely an absolute brightness threshold value Second, classify the optimal luminance ratio threshold ; When (when) > And all that < When the pupil is detected, the light spots are concentrated near the pupil edge and marked as a state A; When (when) > But part of < When the light spot part is driven into the pupil, the state B is marked; When (when) > And is also provided with > And when the brightness of the center and the four corners is judged to meet the requirement, the state C is marked.
8. The OCT retinal partitioning luminance adaptive sharpness imaging adjustment method according to claim 7, wherein the OCT retinal image exhibits a central bright but four corners dark when in state a, and the error function is constructed based on the target luminance value, the central region average luminance, and the four corners average luminance: ; ; Wherein, the Is an error function in the PID; Is the target brightness value; indicating the current time Is a central region average luminance of (2); indicating the current time Average brightness at four corners of (a); Representing the time; And The luminance weights are respectively the center and the four corners.
9. The OCT retinal partitioning luminance adaptive clear imaging adjustment method of claim 7, wherein the OCT retinal image presents a partial angle darkness when in state B, indicating a spot decentration or tilt, wherein the decentration or tilt error is calculated first, and then an error function is constructed based on the decentration or tilt error: ; ; Wherein, the Is an error function in the PID; Is the target brightness value; indicating the current time Is a central region average luminance of (2); indicating the current time Average brightness at four corners of (a); Representing the time; And Respectively representing an X-direction error and a Y-direction error; 、、 And The luminance weights of the center, four corners, X-direction error and Y-direction error are respectively represented.
10. The OCT retinal partitioning luminance adaptive clear imaging adjustment method of claim 9, wherein the specific calculation formulas of the X-direction error and the Y-direction error are: ; 。
11. The OCT retinal partitioning luminance adaptive clear imaging adjustment method of claim 9, wherein: If it is Indicating that the right side is brighter than the left side, the light spot is left, and at the moment, the light needs to be shifted to the right or the incidence is deviated to the right; If it is Indicating that the left side is brighter than the right side, and the light spot is right, and at the moment, the light needs to be shifted to the left or the incidence is left; If it is Indicating that the upper side is brighter than the lower side, the light spot is lower, and the light needs to be moved upwards or the incidence is deviated upwards; If it is Indicating that the underside is brighter than the upper side and that the spot is on the upper side, in which case it is necessary to shift the light downwards or to deflect the incidence downwards.
12. The OCT retinal partitioning luminance adaptive sharpness imaging adjustment method according to claim 1, further comprising, if the target luminance value is not a preset sharpness after tracking by the constructed error function, performing PID adjustment cyclically until imaging reaches the preset sharpness.
OCT retina partition brightness self-adaptive clear imaging adjustment system, which is characterized by comprising: A multi-region determining module configured to acquire an OCT retina image, determine five regions in total of the center and four corners of the OCT retina image; The brightness characteristic extraction module is configured to extract brightness characteristics of five areas, including central area average brightness, four corner area average brightness, global average brightness, four corner average brightness and four corner relative center ratio; The spot position positioning module is configured to determine the relative position of the OCT retina image spot and the pupil based on the relation between the brightness characteristics of the five areas and a preset threshold value; And the PID tracking and adjusting module is configured to construct a corresponding error function according to the relative positions of the OCT retina image light spots and pupils, and track target brightness values of the five areas by adopting a PID control method to realize the adjustment of the light spot positions so as to enable OCT retina imaging to reach preset definition.
14. A computer readable storage medium having stored thereon a program which when executed by a processor performs the steps in the OCT retinal partitioning luminance adaptive sharp imaging adjustment method according to any one of claims 1-12.
15. An electronic device comprising a memory, a processor and a program stored on the memory and executable on the processor, wherein the processor performs the steps in the OCT retinal partitioning luminance adaptive sharp imaging adjustment method of any one of claims 1-12 when the program is executed.

Description

OCT retina partition brightness self-adaptive clear imaging adjustment method and system Technical Field The invention belongs to the technical field of OCT imaging, and particularly relates to an OCT retina partition brightness self-adaptive clear imaging adjusting method and system. Background Optical coherence tomography (optical coherence tomography, OCT) is a technique that uses the interference principle of light to achieve non-contact three-dimensional detection. The technology can accurately reconstruct cross section and three-dimensional structure images of the inside of a tissue by capturing reflected light and back scattering light signals of the tissue of the sample, and the technology becomes a gold standard for diagnosis of ophthalmic diseases by virtue of the advantages of high resolution, no invasion, high real-time performance, high sensitivity and the like. Currently, in the process of testing human eyes by OCT equipment, determining the position of a pupil and whether an incident light spot correctly enters the pupil range is a key step for realizing automatic adjustment and imaging definition of the equipment. However, there are still a number of limitations in this process. The existing OCT automatic adjustment technology mainly relies on simple threshold segmentation, continuous frame cross correlation or single definition index of pupil camera images to judge the spot position and imaging state, but the methods are easily interfered by cornea reflection, tear film reflection, pupil edge blurring, field brightness non-uniformity and other factors, whether the spot completely enters the pupil can not be accurately identified, and the offset direction and the offset amount are difficult to judge. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides a self-adaptive clear imaging adjusting method and a self-adaptive clear imaging adjusting system for the brightness of an OCT retina zone, which are used for automatically judging whether a light spot completely enters a pupil range or not by analyzing brightness distribution of each azimuth angle of an OCT visual field and combining the brightness index of a pupil camera and detecting brightness of each azimuth angle and the center during OCT retina imaging, and adjusting the whole equipment and the movement of a reference arm according to a judging result so as to adjust the equipment, thereby realizing automatic closed-loop imaging optimization from coarse adjustment to fine adjustment and clear imaging. To achieve the above object, one or more embodiments of the present invention provide the following technical solutions: The first aspect of the invention provides an OCT retina partition brightness self-adaptive clear imaging adjustment method. The OCT retina partition brightness self-adaptive clear imaging adjusting method comprises the following steps: acquiring an OCT retina image, and determining five areas in the center and four corners of the OCT retina image; extracting brightness characteristics of five areas, including average brightness of a central area, average brightness of four corners, overall average brightness, average brightness of four corners and relative center ratio of four corners; determining the relative position of OCT retina image facula and pupil based on the relation between the brightness characteristics of the five areas and a preset threshold value; And constructing a corresponding error function according to the relative positions of the OCT retina image facula and the pupil, tracking target brightness values of the five areas by adopting a PID control method, and realizing the adjustment of the position of the facula so as to enable OCT retina imaging to reach preset definition. A second aspect of the invention provides an OCT retinal partitioning luminance adaptive sharpness imaging adjustment system. An OCT retinal partitioning luminance adaptive clear imaging adjustment system comprising: A multi-region determining module configured to acquire an OCT retina image, determine five regions in total of the center and four corners of the OCT retina image; The brightness characteristic extraction module is configured to extract brightness characteristics of five areas, including central area average brightness, four corner area average brightness, global average brightness, four corner average brightness and four corner relative center ratio; The spot position positioning module is configured to determine the relative position of the OCT retina image spot and the pupil based on the relation between the brightness characteristics of the five areas and a preset threshold value; And the PID tracking and adjusting module is configured to construct a corresponding error function according to the relative positions of the OCT retina image light spots and pupils, and track target brightness values of the five areas by adopting a PID control method to realize the adjustme