Modified Alpha-Rooting Color Image Enhancement Method On The Two-Side 2-D Quaternion Discrete Fourier Transform And The 2-D Discrete Fourier Transform
This work addresses color fidelity in image processing for applications like photography or computer vision, but it is incremental as it modifies an existing alpha-rooting method using quaternion transforms.
The paper tackles the problem of color image enhancement by proposing a quaternion-based method that processes color images in their original color space, rather than channel-by-channel, and shows that this approach yields images closer to genuine color representation compared to traditional 2-D DFT methods, with quantitative improvements measured using CEME and optimized via genetic algorithms.
Color in an image is resolved into 3 or 4 color components and 2-Dimages of these components are stored in separate channels. Most of the color image enhancement algorithms are applied channel-by-channel on each image. But such a system of color image processing is not processing the original color. When a color image is represented as a quaternion image, processing is done in original colors. This paper proposes an implementation of the quaternion approach of enhancement algorithm for enhancing color images and is referred as the modified alpha-rooting by the two-dimensional quaternion discrete Fourier transform (2-D QDFT). Enhancement results of this proposed method are compared with the channel-by-channel image enhancement by the 2-D DFT. Enhancements in color images are quantitatively measured by the color enhancement measure estimation (CEME), which allows for selecting optimum parameters for processing by the genetic algorithm. Enhancement of color images by the quaternion based method allows for obtaining images which are closer to the genuine representation of the real original color.