35 results about "Optical scanning holography" patented technology

The invention discloses a method for improving an optical scanning holographic tomography effect, and belongs to the field of optical tomography. The method can solve the defect in the conventional optical scanning technology that restored section images have louder out-of-focus noise, in real time. The method comprises the following steps: utilizing a random phase in the optics encryption technique, changing a certain pupil function in a conventional optical scanning holographic system into a stochastic phase pupil function, and equaling restore of out-of-focus layer images into decryption under the condition of mistakenly decrypting a secret key, thereby enabling the out-of-focus layer images overlaid on the restored section images to be gaussian white noise with statistical independence and greatly reducing the influence of the out-of-focus noise on the focus layer images. Meanwhile the out-of-focus noise can also be filtered through design of a gaussian filter, so that the longitudinal resolution of the system can be improved; besides, through the adoption of the method, the bandwidth of the optical transfer function is wider, and the transverse resolution of the restored section images can be higher.

The invention provides an improved method which adopts a spiral phase plate to generate vortex beams so as to carry out edge extraction, belongs to the field of optical scanning and image reconstruction, and mainly solves a problem of suppressing the spiral phase plate to diffract side lobes. In an optical scanning holographic system which carries out edge extraction by adopting the spiral phase plate, suppression for the side lobes is realized through reducing the radius of the spiral phase plate, and a frequency domain expression of the corrected vortex beams is provided, thereby improving the resolution of edge extraction. The method provided by the invention effectively improves the resolution of edge extraction, and the side lobe suppressing method is applicable to various fields.

An optical scanning holographic image edge extracting method based on a double-hole pupil belongs to the technical field of the optical scanning holographic technology. The method includes the following steps: 1 arranging the double-hole pupil to be that P2a (x, y)= sigma (x-x1, y-y1) to obtain a first Fresnel zone plate h1 and conduct first two-dimensional holographic scanning to obtain a hologram s1; 2 arranging the double-hole pupil to be that P2b (x, y)= sigma (x-x2, y-y2) to obtain a second Fresnel zone plate h2 and conduct second two-dimensional holographic scanning to obtain a hologram s2 to record more object high frequency information; 3 conducting Fourier transform on the holograms obtained through the two-dimensional holographic scanning, and a conjugate gradient method is introduced to conduct inverse problem solving. The method is simple in structure and easy to operate, has high practicability, can achieve edge extraction of clear objects and has high application value.

The invention relates to a complex amplitude object reconstruction device based on the optical scanning holographic technique. The complex amplitude object reconstruction device comprises a difference frequency laser coherent unit, a two-dimensional scanning unit, a photoelectric information receiving and processing unit and a computer reconstruction complex amplitude unit; the reconstruction of the complex amplitude object is realized based on the difference frequency scanning technology which is simpler and easy to realize when being compared with the conventional coherent optical scanning holographic technique. The complex amplitude object reconstruction device can be applied to the field of biology microscope, particularly to the field of transparent or weak-absorption biological sample detection, has the advantage of being superior to other biological imaging techniques, can realize coherent-imaging on the premise of ensuring the imaging resolution, can further obtain more information of the sample related to the refractive index, thereby being quite good in the application prospect in biomedicine.

The invention discloses an optical scanning holographic technique without mechanical motion scanning and belongs to the field of optical imaging. The optical scanning holographic technique is used for improving the traditional optical scanning holographic system. According to the optical scanning holographic technique, a digital micro-mirror device is used for replacing a two-dimensional mechanical scanning device in the traditional system and a compressing sensitive technique is applied to the two key links of data recording and plural hologram reconstruction, so that the problems caused by the factors, such as, precision and jittering of mechanical motion scanning in the traditional system are solved, the volume of to-be-recorded data of the system is extremely reduced, and the technique also can be used for reconstructing images with acceptable quality even under the condition of lower sampling rate.

The invention discloses an optical scanning holographic image recognition technology based on a convolution neural network, belongs to the field of optical scanning holography and depth learning, andmainly aims to solve the problem concerned with optical scanning holographic image recognition. The convolution neural network is used to recognize a hologram. The recognition of optical scanning hologram is realized effectively and intelligently. The hologram recognition method is applicable to various fields.

The invention belongs to the field of optical scanning holography, and provides a method for eliminating defocusing noise based on a two-dimensional best histogram entropy method and a genetic algorithm. First, a laser beam is split into two beam paths by a first polarization beam splitter, wherein the first pupil is a random phase pupil p1 (x, y) = exp j [2 Pai r (x, y)] and the second pupil is p2 is p1 (x, y)=1. Through the arrangement of the optical pupils, the defocusing noise is converted into the form of speckle noise. Then the total entropy H (s, t) of the two-dimensional histogram is obtained by using the two-dimensional best histogram entropy method to the re-constructed and obtained grayscale image and based on this, a fitness function is adopted and the genetic algorithm searches the optimal threshold. According to the invention, through the extraction of the grayscale information of an image, the two-dimensional best histogram entropy method is utilized to select a threshold and an improved genetic algorithm is utilized to speed up the converging speed, which increases the threshold searching efficiency so as to obtain the optimal threshold for image segmentation and to effectively increase the imaging quality of slices.

The invention provides a self-focusing method for obtaining a holographic image through an average gradient function, and belongs to the field of optical scanning holography and self-focusing. The self-focusing problem of the holographic image is mainly solved. Self-focusing is realized by calculating the average gradient function value of the reconstructed image; the self-focusing problem of theholographic image can be effectively solved; meanwhile, the self-focusing problem of other types of images can be solved by means of the average gradient function.

The invention provides a method for eliminating random encrypted optical scanning holography defocus noise, and belongs to the field of the optical encryption and holography reconstruction. The defocus noise problem in the random encrypted optical scanning holography technology is mainly solved. The defocus noise of the random encrypted optical scanning holography is eliminated by mainly using convex optimization reconstruction and high-order amplification; the influence on the holography reconstruction by the optical scanning holography system defocus noise is effectively eliminated, and theresolution of a holographic image is improved.

The invention discloses a multi-image parallel encryption method for non-cascade optical scanning holography, and belongs to the field of optical encryption. A plurality of plaintext images with different depths can be encrypted at the same time, and each image can be independently and privately decrypted. According to the invention, a series of different structure patterns are dynamically switched at the pupil to replace a mechanical scanning process. The structure patterns are created by using a modulation measurement matrix, the modulation measurement matrix is obtained by matrix multiplication of an orthogonal modulation matrix and a sensing matrix, and different images correspond to different substructure patterns. Due to the fact that the plaintext image can be distinguished before sampling by means of the quadrature modulation characteristic, the image to be encrypted does not need to be preprocessed, and defocus noise suppression does not need to be conducted on the decrypted image. In addition, the use of the modulation measurement matrix expands the key space. Due to the characteristics, the safety and the practicability of the holographic multi-image encryption system based on optical scanning are greatly improved.

The invention discloses a self-organizing map neural network-based method for eliminating optical scanning holographic defocus noise, belongs to the fields of optical scanning holography and image noise elimination, and mainly solves the problem of defocus noise in the optical scanning holography. By virtue of the clustering analysis capability of the self-organizing map neural network, the defocus noise in reestablished images which are subjected to random encryption treatment can be eliminated. By virtue of the method, the problem of defocus noise in optical scanning holography can be solvedeffectively, and the noise eliminating method is applicable to each field.

The invention discloses an optical scanning holographic self-focusing method based on an edge gray scale difference function and belongs to the technical field of optical scanning holographic and self-focusing. The method comprises following steps of acquiring digital holographic images, carrying out equal step length rebuilding, calculating an edge brightness matrix and calculating an edge gray scale difference function value. According to the invention, by calculating the edge gray scale difference function value of a real part of the rebuilt holographic image, self-focusing is achieved. Inthis way, the self-focusing problem of the holographic image can be effectively solved and the edge gray scale difference function value can serve as a focusing evaluation index of other types of images.

An optical scanning holography system includes a polarization-sensitive lens configured to receive a linearly polarized beam and generate a first spherical wave of right-handed circular polarized light having a negative focal length and a second spherical wave of left-handed circular polarized light having a positive focal length, a first polarizer configured to pass only a beam component therethrough in a predetermined polarization direction among components of the generated first and second spherical waves, a scanning unit configured to scan an object by using an interference beam generated between the first and second spherical waves passing through the first polarizer, and a first photodetector configured to detect a beam reflected from the object.

The present invention relates to an inline scanning holography system for a phosphor and a transmitter. According to the present invention, the inline scanning holography system includes a polarization sensitive lens that receives a linearly polarized beam and generates a first spherical wave of right-handed circular polarized light having a negative focal length and a second spherical wave of left-handed circular polarized light having a positive focal length, a polarizer that passes only a beam component in a predetermined polarization direction therethrough among components of the generated first and second spherical waves, a scanning unit for scanning a phosphor by using an interference beam generated between the first and second spherical waves passing through the polarizer, and a first photodetector that detects a fluorescent beam diverged from the phosphor. According to the present invention, a high-efficiency and high-quality optical scanning holography for a phosphor or a transmitter may be implemented.

The invention proposes a self-focusing and reconstruction method of optical scanning holography based on connected domains, belongs to the field of optical scanning holography technology and image reconstruction, and mainly solves the problem of holographic reconstruction in optical scanning holography. The invention uses the method of connected domains to mark the image of the hologram and obtain the area of ​​the image area, and realizes the self-focusing and reconstruction of the hologram through the law of area change. The invention effectively realizes the holographic reconstruction in the optical scanning holography, and the image reconstruction method is applicable to various fields.

The invention discloses an off-axis scanning holographic three-dimensional target real-time joint transformation recognition system and method, and belongs to the technical field of optical scanning holographic three-dimensional object real-time recognition. The recognition system comprises a laser, a spatial filter, a first lens, a first beam splitter, a first reflective mirror, a second lens, a shutter, a second reflective mirror, a second beam splitter, a first objective table, a third lens, a first photoelectric detector, a computer, a third reflective mirror, a spatial light modulator, a fourth lens, a second objective table, a second photoelectric detector and a real-time display. The three-dimensional object information is recorded in an off-axis scanning holographic mode, a complex electrical signal processing unit in traditional optical scanning holography is omitted, the light path of the system is simplified, and the recognition efficiency of the three-dimensional target object of the system is improved. The three-dimensional object hologram is recognized through optical joint transformation, the problem of accurate positioning points in matching correlation filtering recognition does not exist, the structure is flexible, and correlation operation is easy to achieve.

The invention proposes a holographic scanning spatial distance extraction method based on wavelet transform and connected domain, belongs to the field of optical scanning and image reconstruction, and mainly solves the problem of automatically finding the axial spatial position of an object to be measured. In the traditional optical scanning holographic system, the invention extracts the edge information of the reconstructed image through wavelet transform, and uses the connected domain algorithm to remove the defocus noise edge, thereby improving the accuracy of spatial distance extraction. The invention can effectively realize spatial distance extraction and improve the accuracy of spatial distance extraction, and this method is applicable to many fields.