Texture Based Fractal Imagery Modeling, Rendering And Morphing Algorithm

Fractal graphics is an important part of computer graphics, the main study of fractal graphics include modeling shapes of fractal feature with fractal model, and using fractal rendering and morphing algorithm to generate colorful and variform fractal imagery, and because the fractal model has simple definition and uniform rendering algorithm, it now become more and more popular. Most of the fractal model is applied in modeling nature forms and encoding images.The former fractal model are not fit for most of the objects, so we propose a new fractal model, which can deal with a sort of complexity scene of unconspicuous fractal feature. We also advance the fractal imagery rendering algorithm according to the new fractal model. Finally, a fractal morphing algorithm which can model continuous and dynamic scene without distortion has been put forward.The main contribution and innovation of this thesis are summarized as follows:1) Texture based IFS model: choose an image which inner sub-image are close to each other, i.e. local self-similarity image, use sub-image as texture, scratch all the sub-image out, and replace with points, then we can construct the IFS on the point set using collage theorem.2) Texture based fractal imagery rendering algorithm: first generate a set of vectors with VVR algorithm, and a length and wide number are computed by comparing with the iterated depth, then with the three factors above, a rectangle can be calculated. By mapping textures to all the rectangles, a fractal image with similar parts everywhere is created; More jobs has been done to improve on the proposed algorithm by reconstructint the vectors, which are derived from the'orientation'of the sub-image in a real image with method of elicitation, and finally by rendering on TIFS model extracted from a real image, a fractal imagery similar to its original one can be attained.3) IFS local attractor's approximate convex-hull computing algorithm and a feature corresponding method based on local approximate convex-hull and revolving matching: affine transformation's corresponding has to be decided before morphing between two IFSs, and as each local attractor separated from the IFS attractor is attached to different transformation, the corresponding between the transformations is also equivalent to that of the local attractors. By searching a most similarity matching on local convex-hull based on revolving matching, a feature corresponding is decided.4) TIFS model's morphing algorithm: a morphing algorithm both applied to real and virtual TIFS model is proposed, firstly, the feature corresponding is only computed on IFSs without considering the textures, and then the mid IFS is calculated by linear interpolating between original and target IFS, finally, a sequence of fractal imagery is obtained by using texture based fractal imagery rendering algorithm to render mid IFSs with textures. We also simulate a real dynamic explosion of firework, as a result, the dynamic fractal firework can achieve a good effect in real time. In addition, an animation of"fracture leaf"has a fractal shape with fracture everywhere interior is acquired by morphing between Fern TIFS and Maple leaf TIFS.The modeling procedure in this paper can be easily handled, all steps only include scratching sub-image interactively, and transforming polygon to piece collage together. Texture based fractal imagery rendering algorithm add special effect to the fractal image, and by morphing with which can achieve a real dynamic scene, that extent the representation of fractal graphics.