CN-122016059-A - Light intensity correction method of interference image and electronic equipment

CN122016059ACN 122016059 ACN122016059 ACN 122016059ACN-122016059-A

Abstract

The invention discloses a light intensity correction method of an interference image and electronic equipment, and relates to the technical field of spliced telescope co-phase detection. And after the actual interference image is obtained, correcting the gray value of the corresponding pixel in the actual interference image by using the correction coefficient to obtain a target interference image, namely, correcting the light intensity of the interference image. In addition, after the correction coefficient of each pixel is obtained, the correction is carried out pixel by pixel based on the correction coefficient of each pixel, thereby improving the correction precision of the interference image and further improving the measurement precision of the synthetic phase.

Inventors

ZHENG JIANING
HE XIU
Ding Yigao
ZHANG NING

Assignees

中国科学院长春光学精密机械与物理研究所

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (10)

1. A light intensity correction method of an interference image, comprising: Acquiring a sample interference image data set acquired by an interferometer under a light source with a target wavelength, and acquiring gray values of pixels in the sample interference image data set; Determining the value of a parameter representing the gray value discrete degree and the value of a parameter representing the gray value reference level corresponding to each pixel based on the gray value of each pixel; acquiring an actual interference image obtained when the light source with the target wavelength is selected for interference measurement, and acquiring the gray value of each pixel in the actual interference image; and correcting the gray value of the corresponding pixel in the actual interference image based on the value of the parameter representing the gray value discrete degree and the value of the parameter representing the gray value reference level corresponding to each pixel so as to obtain a target interference image.
2. The method of claim 1, wherein acquiring a sample interference image dataset acquired by the interferometer at a light source of a target wavelength comprises: controlling a moving device connected with the splice lens to move under the condition that the intensity of the light source with the target wavelength is controlled to be the target intensity and the exposure time is controlled to be the target exposure time so as to drive the splice lens to move along the optical axis direction; And in the moving process of the splicing mirror, controlling an interferometer to image the splicing mirror for a plurality of times so as to obtain the sample interference image data set.
3. The method according to claim 1, wherein before determining the value of the parameter representing the degree of dispersion of the gradation value and the value of the parameter representing the reference level of the gradation value for each pixel based on the gradation value of each pixel, further comprising: Acquiring the gray average value of all pixels in a target area where a preset pixel is located, wherein the preset pixel is any pixel in the sample interference image data set; Acquiring a gray difference value between the gray value of the preset pixel and the gray average value; Marking the preset pixel as an abnormal pixel and taking the gray average value as the gray value of the preset pixel under the condition that the gray difference value is detected to be larger than a threshold value, so as to obtain a new sample interference image dataset; The determining the value of the parameter representing the gray value discrete degree and the value of the parameter representing the gray value reference level corresponding to each pixel based on the gray value of each pixel comprises: And determining the value of the parameter representing the gray value discrete degree and the value of the parameter representing the gray value reference level corresponding to each pixel based on the gray value of each pixel in the new sample interference image data set.
4. A method of intensity correction of an interference image according to claim 3, wherein determining the value of the parameter characterizing the degree of dispersion of the gray value and the value of the parameter characterizing the reference level of the gray value for each pixel based on the gray value of each pixel in the new sample interference image dataset comprises: determining a splicing mirror area in the new sample interference image data set based on the gray values of the pixels in the new sample interference image data set; acquiring an image dataset corresponding to a splicing mirror region in a new sample interference image dataset; And determining the value of the parameter representing the gray value discrete degree and the value of the parameter representing the gray value reference level corresponding to each pixel based on the gray value of each pixel in the image data set corresponding to the splicing mirror region.
5. The method of claim 4, wherein determining a new stitching mirror region in the sample interference image dataset based on gray values of pixels in the new sample interference image dataset comprises: acquiring a reference image from a new sample interference image data set and a residual image except the reference image, wherein the reference image is any image in the new sample interference image data set; acquiring the absolute value of the difference between the gray value of each pixel in the residual image and the gray value of the corresponding pixel in the reference image; acquiring the sum of absolute values of differences corresponding to the same pixel of the residual image, and determining a difference image based on the sum of absolute values of differences corresponding to all pixels; performing binarization processing on the difference image, and performing morphological closing operation to obtain a spliced mirror template image; and performing template matching on all images in the new sample interference image dataset by using the template image of the splicing mirror so as to obtain a splicing mirror region in the new sample interference image dataset.
6. The method according to claim 4, wherein determining the value of the parameter characterizing the degree of dispersion of the gradation value and the value of the parameter characterizing the reference level of the gradation value for each pixel based on the gradation value of each pixel in the image data set for the split mirror region comprises: Respectively performing curve fitting on gray values of the same pixel in an image data set corresponding to the splicing mirror region, and determining a gray maximum value and a gray minimum value at the pixel position according to the fitted curve; establishing a global bright image according to the gray maximum value corresponding to all pixel positions, and establishing a global dark image according to the gray minimum value corresponding to all pixel positions; Acquiring a gray maximum value and a gray minimum value at the same pixel position in the global bright image and the global dark image; half of the difference between the maximum gray value and the minimum gray value at the same pixel position is obtained to determine the value of the parameter representing the gray value discrete degree corresponding to each pixel; Half of the sum of the maximum gray value and the minimum gray value at the same pixel position is acquired to determine the value of the parameter corresponding to each pixel and representing the gray value reference level.
7. The method according to any one of claims 1 to 6, characterized by further comprising, before acquiring the gray value of each pixel in the actual interference image: detecting abnormal pixels of the actual interference image to obtain a new actual interference image; Determining image data corresponding to an actual splicing mirror area based on gray values of pixels in the new actual interference image; The step of obtaining the gray value of each pixel in the actual interference image comprises the following steps: And acquiring gray values of pixels in the image data corresponding to the actual splicing mirror area.
8. The method according to any one of claims 1 to 6, wherein correcting the gray value of the corresponding pixel in the actual interference image based on the value of the parameter characterizing the degree of dispersion of the gray value and the value of the parameter characterizing the reference level of the gray value, to obtain the target interference image, comprises: Acquiring a first difference value between a gray value of a target pixel in the actual interference image and a value of a parameter representing a gray value reference level, wherein the target pixel is any pixel in the actual interference image; acquiring a ratio between the first difference value and a value of a parameter representing the degree of dispersion of the gray value, and taking the ratio as a corrected gray value corresponding to the target pixel; And obtaining a target interference image based on the corrected gray values corresponding to the target pixels.
9. The method for correcting the light intensity of an interference image according to claim 8, further comprising, after obtaining the target interference image: and controlling the light source with the new target wavelength to work, returning to the sample interference image data set acquired by the acquisition interferometer under the light source with the target wavelength, and acquiring the gray value of each pixel in the sample interference image data set.
10. An electronic device, comprising: A memory for storing a computer program; a processor for implementing the steps of the light intensity correction method of an interference image according to any one of claims 1 to 9 when executing said computer program.

Description

Light intensity correction method of interference image and electronic equipment Technical Field The invention relates to the technical field of spliced telescope co-phase detection, in particular to a light intensity correction method of an interference image and electronic equipment. Background The spliced telescope has become one of the important directions of the development of the large caliber telescope in the future by virtue of the advantages of low processing difficulty, flexible construction, convenient expansion and the like of the single sub-lens. In order to achieve the resolution capability similar to that of a single primary mirror, the spliced telescope is required to realize accurate detection of the common phase error among all the sub-mirrors, so as to guide the assembling and adjusting process. At present, various common phase error detection methods exist, wherein the multi-wavelength synchronous phase shift interferometry method has the advantages of high precision, simple light path and short detection time, can effectively overcome the defect of small dynamic range, and can well solve the common phase detection problem. However, for multi-wavelength synchronous phase-shift interferometry, the inconsistent light intensities of different wavelengths and different phase-shift images bring great difficulty to the processing of interference images, the improper processing can generate ripple errors consistent with the trend of interference fringes in the measurement result, and the ripple errors can be further amplified due to the error amplification effect during the calculation of the synthetic phase, so that the final measurement accuracy is seriously affected. In the conventional light intensity consistency correction method, a special calibration device is arranged in a multi-wavelength synchronous phase-shift interferometry device to shield reference light or measuring light, light spot images corresponding to the reference light or the measuring light are collected independently, and light intensity consistency correction is carried out on the interference images according to the light intensity average value of the light spots. In the method, a special calibration device is required to be built in, and the calibration scene is inconsistent with the real measurement scene, so that ripple errors are often remained after correction and phase shift error correction, and the measurement accuracy of the synthetic phase is reduced. Therefore, how to effectively implement the light intensity correction of the phase shift image to improve the measurement accuracy of the synthetic phase is a technical problem that needs to be solved by those skilled in the art. Disclosure of Invention The invention aims to provide a light intensity correction method and electronic equipment of an interference image, which are used for solving the technical problems that a special calibration device is needed to be built in the related light intensity consistency correction method, and a calibration scene is inconsistent with a real measurement scene, so that after correction and phase shift error correction, ripple errors are often remained, and the measurement accuracy of a synthetic phase is reduced. In order to solve the above technical problems, the present invention provides a light intensity correction method for interference images, including: Acquiring a sample interference image data set acquired by an interferometer under a light source with a target wavelength, and acquiring gray values of pixels in the sample interference image data set; Determining the value of a parameter representing the gray value discrete degree and the value of a parameter representing the gray value reference level corresponding to each pixel based on the gray value of each pixel; acquiring an actual interference image obtained when the light source with the target wavelength is selected for interference measurement, and acquiring the gray value of each pixel in the actual interference image; and correcting the gray value of the corresponding pixel in the actual interference image based on the value of the parameter representing the gray value discrete degree and the value of the parameter representing the gray value reference level corresponding to each pixel so as to obtain a target interference image. Illustratively, acquiring a sample interference image dataset acquired by an interferometer at a light source of a target wavelength comprises: controlling a moving device connected with the splice lens to move under the condition that the intensity of the light source with the target wavelength is controlled to be the target intensity and the exposure time is controlled to be the target exposure time so as to drive the splice lens to move along the optical axis direction; And in the moving process of the splicing mirror, controlling an interferometer to image the splicing mirror for a plurality of times so as to obtain t