11 results about "Distortion function" patented technology

The invention discloses a multi-parameter distortion compensation method for a fractured rock mass seepage similar model test, and relates to the technical field of rock mass engineering physical model tests. The method comprises the following steps of: firstly, determining two constraint conditions that the fluid property is invariable and the gravitational acceleration is invariable, correspondingly selecting a basic physical quantity and extracting a core criterion; then analyzing three types of distortion sources of geometric dimensions, dielectric materials and boundary conditions, and establishing a distortion function according to result parameters of seepage flow velocity, seepage flow and seepage pressure; secondly, parameters difficult to control are selected as distortion items, parameters easy to regulate and control are selected as compensation items, the distortion items are substituted into a distortion function to obtain a distortion ratio, the optimal distortion ratio of the compensation items is solved based on a compensation balance formula, and the parameters are adjusted; and finally verifying the interval range of the actually measured distortion ratio. According to the method, the multi-source distortion coupling influence is accurately quantified, the compensation pertinence and precision are improved, operation is easy and convenient, universality is high, and reliable support is provided for underground engineering seepage research.

The invention relates to the technical field of optical precision interference measurement, in particular to a correction method for projection distortion detection of a primary mirror of a dynamic interferometer and a related product, and the method comprises the steps: obtaining a first coordinate and a second coordinate; determining a zero distortion point; obtaining an ideal imaging point set and an actual mapping point set after system projection through ray tracing; fitting to obtain a distortion function representing the distortion of the optical system; performing point-by-point correction on a phase diagram obtained by interference measurement, mapping pixel coordinates of the phase diagram into workpiece coordinates, obtaining interference measurement data corresponding to the actual surface of the primary mirror, and completing distortion correction; according to the method for correcting the surface shape projection distortion during interference measurement of the high-precision primary mirror of the large-aperture dynamic interferometer, the problem that in the process of assembling, repairing and developing the large-aperture Twyman type dynamic interferometer, the projection distortion effect of a detection system causes the loss of an accurate matching relation between a workpiece coordinate system and a detection coordinate system is solved.

The invention relates to the technical field of video coding and decoding, and discloses an end-to-end video coding and decoding method and device, equipment and a storage medium. The method comprises the following steps: acquiring multiple frames of original images of an original video sequence and constructing an end-to-end video coding and decoding model; inputting the (t-1) th frame of original image and the t th frame of original image into an end-to-end video coding and decoding model to obtain a distortion function and a code rate function; calculating the gradient of the distortion function and the gradient of the code rate function, and solving the optimal weight based on the gradient of the distortion function and the gradient of the code rate function; calculating a parameter updating gradient based on the optimal weight, and updating parameters of the end-to-end video coding and decoding model based on the parameter updating gradient to obtain an optimized end-to-end video coding and decoding model; and coding and decoding multiple frames of images to be reconstructed by using the optimized end-to-end video coding and decoding model to obtain multiple frames of reconstructed images. According to the method, the training stability is improved, and the problems of low overall coding efficiency, high calculation complexity and unbalanced rate gradient updating in a traditional method are solved.

The application relates to the technical field of integrated circuits, and discloses a method for simultaneously realizing pre-distortion and pre-emphasis and a transmitting end modulator circuit thereof. A first selector multiplies a first value or a second value in a code word with a corresponding coefficient in a first lookup table, the corresponding coefficient being a product of a pre-distortion coefficient and a pre-emphasis coefficient of the first or second value; a second selector multiplies a third value or a fourth value in the code word with a corresponding coefficient in a second lookup table, the corresponding coefficient being a product of a pre-distortion coefficient and a pre-emphasis coefficient of the third or fourth value; and output results of the first selector and the second selector are added. The application can simultaneously support both pre-emphasis and pre-distortion functions.

The economic tolerance analysis method, device, equipment and storage medium of the optical system provided by the embodiment of the application first determine the parameter tolerance of the structure to be analyzed, then determine the distortion function based on the parameter tolerance and use the Taylor formula to determine the change of the distortion when the parameter tolerance changes; then determine the sensitivity coefficient based on the object side of the optical system to solve the sensitivity coefficient in the Taylor formula expansion, so as to determine the parameters that have a great influence on the distortion according to the size of the sensitivity coefficient; finally, determine the best economic tolerance according to the tolerance cost function corresponding to each parameter tolerance, the sensitivity coefficient and the distortion function determined according to the preset processing parameter information, so as to solve the distortion expression and the tolerance cost function determined in the above steps, and determine the size of the parameter tolerance, so that the tolerance value can meet the distortion requirement and the processing cost is the lowest, and the purpose of balancing the economic tolerance is achieved.

A sensing method and apparatus. The method comprises: a first device inputting first compressed information into a decompression model, so as to obtain second sensing information output by the decompression model, wherein the first compressed information is related to first sensing information, the first sensing information comprises information that indicates first power corresponding to at least one spatial position, and the second sensing information comprises information that indicates second power corresponding to the at least one spatial position; and on the basis of a loss function, the first device updating parameters of a compression model and / or the decompression model, wherein the loss function comprises a distortion function between the first sensing information and the second sensing information, the distortion function is related to a power difference corresponding to the at least one spatial position and the maximum first power indicated by the first sensing information, and the power difference corresponding to one of the at least one spatial position refers to the difference between the first power and the second power. The distortion function in the embodiments of the present application enables relatively accurate power recovery at a receiving end, thereby facilitating an improvement in sensing precision.

The invention relates to the technical field of wireless communication, and discloses a limited feedback wireless communication method based on a Lloyd algorithm, and the method comprises the steps: selecting a sample from a preset training sequence, so as to construct an initial codebook containing H code words; according to predefined performance measurement, distributing each channel sample in the training sequence to a codeword capable of enabling the performance measurement to be optimal in the codebook, so as to divide the training sequence into H partitions; for each partition, obtaining a new codeword through optimization calculation so as to form a new codebook; and evaluating the performance loss of the new codebook based on a distortion function, and stopping iteration when the value of the distortion function meets a preset convergence condition. By generating the codebook highly matched with the statistical characteristics of the channel, the average communication capacity of the system is improved under the condition that only a small number of bit indexes need to be fed back, and effective balance between feedback overhead and communication performance is achieved.

The invention provides a multi-domain simultaneous embedding video steganography method and system based on a motion vector index and PU segmentation, and belongs to the technical field of video steganography. On the basis of a traditional motion vector domain embedding method, utilization of a Merge mode PU is added. According to the method, the secret information is embedded by modifying a predicted motion vector flag bit of the PU in the AMVP mode and a segmentation method of the PU in the Merge mode, the mutual influence condition of two embedding domains is considered, the embedding method is reasonably limited, disturbance brought by the embedded secret information is analyzed, a joint distortion function is designed, and the overall distortion of embedded information is minimized through STC coding. Experiments show that in combination with embedding of the Merge mode PU, the steganography capacity is effectively improved, the embedding capacity can be kept stable in videos with various contents, the quality of the embedded video can be flexibly adjusted through a control factor of a distortion function, and in combination with STC coding, disturbance of the algorithm to the quality of the video is small. For a targeted steganography analysis method, good resistance can be kept, and steganography safety is reliable.

The invention discloses a sensing method and device. The first device inputs first compression information to the decompression model to obtain second sensing information output by the decompression model, the first compression information is related to first sensing information, and the first sensing information comprises information indicating first power corresponding to at least one spatial position; the second perception information comprises information indicating second power corresponding to at least one spatial position. The first equipment updates parameters of the compression model and / or the decompression model according to a loss function, the loss function comprises a distortion function between the first perception information and the second perception information, and the distortion function is related to a power difference value corresponding to at least one spatial position and the maximum first power indicated by the first perception information; the power difference value corresponding to one spatial position in the at least one spatial position refers to the difference value of the first power and the second power. According to the embodiment of the invention, the distortion function enables the power recovery of the receiving end to be more accurate, and facilitates the improvement of the sensing precision.

A method for correcting scan data generated by scanning a sample with charged particles and detecting signal charged particles emitted from the sample, the method including selecting at least one scan profile for scanning the sample; and correcting scan data generated by the scanning of the sample, based on at least one known distortion function f(x,y) associated with the at least one selected scan profile.

A digital pre-distortion circuit and technique for a signal being amplified. Digital pre-distortion is performed using a model-based pre-distortion function. Pre-distortion is further corrected using a data-driven pre-distortion function. The model-based pre-distortion function and the data-driven pre-distortion function are trained using training data including a digital loopback signal generated by sampling a loopback signal of an amplifier, the digital pre-distorted signal input to the amplifier for a time period, and an intermediate signal output from the model-based pre-distortion function driven by the digital loopback signal or an output of the data-driven pre-distortion function. Parameters may be continually updated in order to account for changes in characteristics of the amplifier.