Full-bending filtering method, device and system for preserving edge of piecewise linear image

The invention provides a piecewise linear image edge-preserving full-bending filtering method, device and system. The method comprises the following steps: constructing a high-order geometric full-bending filtering model for enabling an image to have an edge-preserving capability; combining a first-order derivative and a second-order derivative on the basis of an objective function of a full-bending filtering model in combination with a multiplication strategy; processing the full-bending filtering model based on a gradient descent method to obtain an Euler-Lagrange type high-order anisotropic nonlinear equation; based on the high-order anisotropic nonlinear equation, a finite difference method is adopted for solving, and a solution of the full-bending filtering model is obtained; determining a target pixel in the image; when an image is processed based on a full-bending filtering model, a plurality of filtering windows are combined to process a plurality of target pixels in parallel, and the maximum differen