• Image Evolution Using 2D Power Spectra

      Gircys, Michael; Department of Computer Science
      Procedurally generated textures have seen use in many applications, are a high-interest topic when exploring evolutionary algorithms, and hold a central interest for digital art. However, there is an existing difficulty in finding suitable heuristics for measuring perceived qualities of an image. Particular difficulty remains for quantifying aspects of style and shape. In an attempt to bridge the divide between computer vision and cognitive perception, one set of proposed measures from previous studies relate to image spatial frequencies. Based on existing research which uses power spectral density of spatial frequencies as an effective metric for image classification and retrieval, we believe this measure and others based on Fourier decomposition may be effective for guiding evolutionary texture synthesis. We briefly compare some alternative means of using frequency analysis to guide evolution of shape and composition, and refine fitness measures based on Fourier analysis and spatial frequency. Our exploration has been conducted with the goals of improving intuition of these measures, evaluating the utility of these measures for image composition, and observing possible adaptations of their use in digital evolutionary art. Multiple evolutionary guidance schemes with consideration of the spatial frequencies' power spectra and phase have been evaluated across numerous targets with mixed results. We will display our exploration of power spectral density measures and their effectiveness as used for evolutionary algorithm fitness targets, particularly for basic compositional guidance in evolutionary art. We also observe and analyze a previously identified phenomenon of spatial properties which could lead to further consideration of visual comfort and aesthetics.
    • Mixed Media in Evolutionary Art

      Maslen, Jordan; Department of Computer Science
      This thesis focuses on creating evolutionary art with genetic programming. The main goal of the system is to produce novel stylized images using mixed media. Mixed media on a canvas is the use of multiple artistic effects being used to produce interesting and new images. This approach uses a genetic program (GP) in which each individual in the population will represent their own unique solution. The evaluation method being used to determine the fitness of each individual will be direct colour matching of the GP canvas and target image. The secondary goal was to see how well different computer graphic techniques work together. In particular, bitmaps have not been studied much in evolutionary art. Results show a variety of unique solutions with the application of mixed media.
    • Non-photorealistic Rendering with Cartesian Genetic Programming using Graphic Processing Units

      Bakurov, Illya; Department of Computer Science
      Non-photorealistic rendering (NPR) is concerned with the algorithm generation of images having unrealistic characteristics, for example, oil paintings or watercolour. Using genetic programming to evolve aesthetically pleasing NPR images is a relatively new approach in the art field, and in the majority of cases it takes a lot of time to generate results. With use of Cartesian genetic programming (CGP) and graphic processing units (GPUs), we can improve the performance of NPR image evolution. Evolutionary NPR can render images with interesting, and often unexpected, graphic effects. CGP provides a means to eliminate large, inefficient rendering expressions, while GPU acceleration parallelizes the calculations, which minimizes the time needed to get results. By using these tools, we can speed up the image generation process. Experiments revealed that CGP expressions are more concise, and search is more exploratory, than in tree-based approaches. Implementation of the system with GPUs showed significant speed-up.