Efficient Image Stylization Based On Smart Phones

Watercolor painting has attracted much attention in the field of non-photorealistic rendering because of its rich artistic expression.Traditional watercolorization algorithms can achieve true rendering of watercolor artistic effects,but they are more complex and only suitable for high-performance desktop devices.This paper proposes the research of image watercolorization technology based on smart phones.From the perspective of drawing effect and algorithm efficiency,the real simulation of the artistic effect of watercolor painting is realized on smart phones.The main work of this paper includes proposing a watercolor stylized drawing algorithm framework,studying the optimization method of stylized drawing algorithm,and realizing a watercolor stylized rendering application based on Android mobile platform.The algorithm framework of watercolor stylized rendering proposed in this paper includes the modules of image abstraction,superimposed watercolor effects and image color adjustment.In the image abstraction module,median filter and mean shift filter are used to remove noise and extract the key information of the original image.In the superimposed watercolor painting effect module,firstly,Sobel operator and morphological erosion operation are used to extract and enhance the edge information of the image to generate the edge darkening effect of the watercolor painting.Then an algorithm is proposed to simulate the gap effect of the watercolor painting.Pixels at the edge of the image contour that are smaller than a certain threshold are randomly offset to achieve the gap effect of watercolor painting.The threshold size and offset size can be flexibly adjusted according to the physical pixels of different devices.Finally,Perlin noise is used to simulate the turbulence and paper texture effects of watercolor painting.In the image color adjustment module,the perfect reflection assumption is used to perform white balance operations on the image to adjust the image color.In order to improve the efficiency of code execution,this paper uses Open MP to optimize the algorithm in parallel according to the software and hardware conditions of the program.Finally,the Android NDK is used to realize the efficient image watercolor stylized rendering function on the Android mobile phone.The experiments validated the effectiveness and efficiency of our work in this thesis.