Research On Image Warping Based On Grid

In the era of rapid development of science and technology,a variety of image editing software has been born.These softwares break the limitation of time and space,so that users can use the software to create and save pictures at any time and place.In children's art education,the cultivation of image reading ability and the cultivation and expression of creativity and thinking ability are the most valued quality cultivation and expansion in modern education.As a kind of image editing technology,image warping can make children use their imagination to creatively deform the objects in the image,so as to effectively reproduce the thinking process of children's understanding of the image.It is conducive to developing children's creativity and stimulating their potential thinking ability.Points or lines are regarded as the control handles to make the image deform intuitively in the traditional image warping technology.But the operation is complex,which is not suitable for children's operation.Therefore,a image warping technology based grid is proposed in this paper,which makes the grid deform by moving the points on the grid,and with high deformation efficiency,simple operation,and applied to children.The work in this thesis mainly includes the following aspects:1.Image warping algorithm based on Gaussian function: Firstly,the image area is gridded,and then the image is pasted to the grid structure.In the process of image warping,the deformation region is set firstly,and then the image is deformed by manipulating each cell vertex.In order to make the deformation vector generated by the movement of deformation points within the deformation range follow the bell structure law,I introduce Gauss function to determine the movement distance of each deformation point.2.Image warping algorithm based on deformation function: In this section,I improve the existing problems of image warping algorithm based on Gaussian function.In order to solve the problem of overflow deformation area of deformation point,I use the principle of backward mapping.By using the radius of deformation area,the coordinates of deformation point,control point and target point to construct a warping function,the problem of uncertain factors in function is solved.And the image deformation is more smooth based on the function.In addition,some constraints are applied to the deformation point of overflow image boundary,which also solves the problem of cell flipping.3.Image interpolation algorithm: After the above-mentioned deformation operations,I proposes an image interpolation algorithm to solve the problem of blur when image is enlarged.Firstly,we raster transformed image.For each point need to be reassigned,all 22 ? subgrids containing it are calculated.Then the color value is divided into three channels: R,G and B for the following operations: for each sub grid,nine sampling points in the grid are used to construct a surface by least square polynomial fitting,and then the coordinates of the points are substituted to calculate their quasi function values.Repeat the above steps to calculate the quasi function values of the points in other fitting surfaces.Finally,all the quasi function values are averaged to get the final value.4.Image warping game: In this paper,I design an image warping game for children.The game can complete the local image warping editing only by clicking and moving the mouse.And the warping points can be visible to assist children in the warping operation.In addition,the system also includes functions such as undo,restore,empty,enlarge,shrink,import pictures and save pictures.In order to meet the needs of children's editing pictures,the system provides some pictures and also supports the import of external files.On the base of the above algorithm,this paper realizes the local image warping based on grid.The experimental results show that the image warping technology can achieve good deformation effect with simple operation and short time.