* * * What are the applications of linear equations?

The * * line equation is one of the most basic formulas in photogrammetry, which expresses the mathematical relationship that the object point, the image point and the projection center (usually the lens center of a photo) are located in a straight line. Details are as follows:

The linear equations of 1 and * * * can be used to solve the transformation relationship between object space coordinates and image space coordinates. By knowing the internal orientation elements and external orientation elements of an image, a linear equation between object space coordinates and image space coordinates can be derived, thus realizing the transformation from object space coordinates to image space coordinates and the inverse transformation from image space coordinates to object space coordinates.

2.* * * line equation can be used to generate epipolar image and digital differential correction. Epipolar image generation is a process of matching oblique photos with horizontal photos to obtain epipolar images. Through the * * * line equation, the points on the oblique photograph can be corresponding to the points on the horizontal photograph, and the epipolar image can be generated.

3. Digital difference correction is to improve the accuracy and readability of the map by correcting the geometric deformation of the image. Using the * * * line equation, the mapping relationship between the corrected image point and the original image point can be established, and digital differential correction can be realized.

4.* * * line equation can also be used to solve orientation elements and transform image points. Orientation elements include rotation matrix, translation vector and other parameters, which describe the relative position relationship between projection center and object space coordinates. Through the * * * line equation, the orientation elements can be solved, so as to realize the positioning and orientation of the object space.

5.* * * line equation can also be used for spatial geometric transformation and graphic clipping. In the field of computer graphics and computer vision, * * * line equation can be used to realize three-dimensional reconstruction of objects, rendering of scenes and virtual reality. In addition, in the field of geographic information system, * * * line equation is also widely used in map making, remote sensing image processing and 3D terrain visualization.

The application of * * line equation in photogrammetry is as follows:

1, aerial photogrammetry: * * line equation can be used for projection transformation and photo correction in aerial photogrammetry. Through the known internal and external orientation elements of the camera, the * * line equation can be established, so as to carry out geometric correction and radiation correction on the photo and obtain accurate geographical information.

2. 3D reconstruction: * * line equation can be used for homonym point matching and coordinate transformation in 3D reconstruction. Through the * * * line equation, the mapping relationship between points with the same name can be established, and the transformation from two-dimensional images to three-dimensional models can be realized, which provides support for the digital protection and measurement of buildings, cultural relics and other objects.

3. Remote sensing image processing: * * line equation can be used for image registration and fusion in remote sensing image processing. Through the linear equation, the images obtained by different sensors can be aligned and fused, which can improve the quality and accuracy of remote sensing images and provide data support for environmental monitoring, resource investigation and other fields.

4. Medical image processing: * * line equation can be used for image registration and segmentation in medical image processing. Through linear equations, multiple medical images from different angles and different parts can be aligned and segmented, providing accurate image information for disease diagnosis and treatment.

5. Visual navigation: Linear equations can be used for target recognition and attitude estimation in visual navigation. Through the linear equation, the mapping relationship between camera coordinate system and navigation coordinate system can be established, and the recognition and attitude estimation of target objects can be realized, which provides technical support for autonomous navigation, robot vision and other fields.