Research On Digital Simulation And Synthesis Of Yunnan Heavy Color Painting

Non-photorealistic rendering (NPR) is an active research topic in current computer graphics domain. Domestic and foreign research institutions and scholars have been working on the digital simulation studies on oil painting, watercolor painting, Chinese painting, Chinese calligraphy and paper cutting, and getting the fruitful results. But the NPR research of Yunnan heavy color painting has not been reported. This dissertation selects for the first time the Ding Shaoguang Yunnan heavy color painting works, which have strong national and regional characteristics, as the research object to study the approach of Yunnan heavy color painting stylized rendering. In order to display the Yunnan heavy color painting's distinctive characteristics of Chinese line drawing and the Western oil painting, the dissertation carries on the digital simulation and synthesis research, designs and implements an Yunnan heavy color digital synthesis system. The dissertation's work is a very meaningful supplement for the research of China unique artistic style digital rendering. Research results can be used for film and television production, book design, architecture decoration, home entertainment, advertising, media, digital entertainment and other areas. The main work is as follows:1. Creating the Yunnan heavy color painting basic graphic element database, designing and implementing a line drawing painting system, this is the foundation of whole Yunnan heavy color painting stylized rendering.Yunnan heavy color painting has distinctive characteristics of line drawing, exaggerated slender body is the most expressive part. In this dissertation, an approach is proposed to extract graphic elements from Yunnan heavy color painting, which can express the characteristics of line drawing, and use them to synthesize Yunnan heavy color line drawings. The graphic elements include five types, such as the hair, face, body, arms and ornaments. They are been included in the graphic element database. The basic graphic element database adopts two-level management model to manage the graphic elements. It can help us to find, add, delete, and modify the graphic elements. Based on it, a Yunnan heavy color line drawing system is designed and implemented. The graphic elements are selected from the database to draw a new line drawing image. The system provides powerful editing and graphic layer tools to edit, modify, deform and combine the graphic elements to finish a new line drawing Image with the characteristic of Yunnan heavy color painting. The new line drawing image will be used to render in subsequent step.2. Propose the generating algorithm of Yunnan heavy color painting unique texture.Yunnan heavy color painting has unique scratch texture and point-patch texture. A LIC (line integral convolution) algorithm based on brush is proposed to simulate the scratch texture. There are three brush kinds, point, round and curve. We can adjust the LIC parameters, the direction of vector filed and the density of noise filed to change the style of scratch texture and obtain the satisfied result. A multi-frequency LIC algorithm based of filling is used to simulate the point-patch texture. The point-patch texture with different size is generated by using different frequency noise filed. In order to show the mixing color effect of point-patch texture, a mixing color model is proposed in the RGB and HSV color space.3. Propose a local color transfer algorithm based on CTWC.The local color transfer algorithm based on CTWC includes two forms: exponential form and Butterworth form. The dissertation compares the local color transfer effects of two methods and finds the rules of their respective parameters how to affect the local transfer effect. Exponential CTWC algorithm has the characteristics of color transfer smooth transition. Butterworth CTWC algorithm can adjust the filter bandwidth and order to control the effect of local color transfer. It can accurately control the region of color transformation. For multi-regional local color transfer, two image fusion models, iterative merge model and weighted average merge model, are used to fuse the multi-regional local color transformation's result images. The color transfer is used for Yunnan heavy color painting digital simulation and stylized rendering in this dissertation.4. Propose texture synthesis accelerated algorithms based on line and II_FFT.The question of how to increase the speed of texture synthesis is studied in this dissertation. The texture synthesis accelerated algorithms based on line and II_FFT are proposed. The algorithm based on line firstly synthesizes a row of texture based on patch, and then synthesizes texture row by row. Because the redundant error calculation is reduced, and the parallel computing is adopted, the synthesis time is shortening in 40 percents. The II_FFT algorithm improves the SSD error calculation method. It adopts the integral image and FFT fast convolution to calculate the SSD error, the texture synthesis speed is observably raised. The texture synthesis technology is used to generate the skin texture, clothes texture and background of Yunnan heavy color painting digital simulation image in this dissertation.5. Designing and implementing the Yunnan heavy color painting rendering system.In this dissertation, a Yunnan heavy color painting rendering system is designed and implemented, which is used to rendering and coloring the line drawing image that was created in ahead step of line drawing. Firstly add the scratch and point-patch texture; then the hollow silhouette enhance and add the background image, last, color transfer and texture synthesis are used to improve the stylized rendering effect. This system includes six modules:scratch texture simulation, point-patch texture simulation, hollow silhouette enhancement, background adding, and color transformation and texture synthesis. They work together to generate the satisfied Yunnan heavy color painting style digital synthesis image.