Forward-looking sonar beam domain image splicing method

Abstract

The invention discloses a foresight sonar beam domain image splicing method, which comprises the following steps of: constructing an expression domain mapping constellation diagram, and forming a data conversion relationship between a beam domain and an image domain; according to an expression domain mapping constellation diagram, splitting actual sonar motion, and constructing an expression domain mapping model in a rotation motion mode and a displacement motion mode; the method comprises the following steps of: adopting an actually measured near-frame sonar image, decomposing the actual sonar motion condition according to rotation motion and displacement motion by taking a previous frame image as a benchmark, and performing image deformation operation on a next frame image by referring to an expression domain mapping model to realize target superposition in the two images; carrying out image fusion on the two beam domain images of which the targets are overlapped by adopting a Laplace pyramid hierarchical fusion strategy; a forward-looking sonar sequence image is adopted, continuous multi-frame data beam domain splicing operation is carried out, and the image is expanded to an image domain through interpolation. According to the method, edge seams generated in the image and splicing are well removed, and a false target value occurring in the fan-shaped expansion interpolation operation splicing process is eliminated.

Description

technical field [0001] The invention belongs to digital image processing technology, and relates to a forward-looking sonar beam domain image mosaic method, in particular to a forward-looking sonar beam domain image mosaic method based on an expression domain mapping model. Background technique [0002] Image stitching is the process of combining images with overlapping regions from different perspectives of the same scene to form a wide-field, information-rich image. Image stitching plays a vital role in digital image processing and has become a popular field in photogrammetry, computer vision, image processing and computer graphics, and is widely used in remote sensing, aerospace, virtual reality, medical imaging, 3D reconstruction and other fields. [0003] The existing mosaic method of forward-looking sonar images is mainly carried out with reference to the method of optical image mosaic, and the content of the two images to be mosaic is completed by feature extraction ...

AI Technical Summary

Problems solved by technology

The fan-shaped outer edge interpolation calculation lacks enough neighboring points to participate, resulting in obvious jumps in the edge gray value of the interpolated edge, which needs to be eliminated by adding templates during splicing, otherwise obvious fan-shaped edges will be left, which increases the splicing. Complexity and calculation time-consuming; for fan-shaped images in the image domain, the gray value of the interpolation point is approximately calculated, and the fusion of the interpolation point value and the real point value of the two images will occur during splicing. If the fusion strategy is not selected properly , it is prone to the problem that the real point value is weakened or even replaced, and the false target value appears, which affects the splicing effect; the fan-shaped image in the image domain will definitely leave a large number of non-pixel areas outside the fan-shaped area during the display process

When image stitching, the non-pixel area will also participate in the calculation, which increases the calculation overhead

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