There has been a profound expansion of digital data both in terms of quality and heterogeneity. Trivial searching techniques of images by using metadata, keywords or tags are not sufficient. Efficient Content-based Image Retrieval (CBIR) is certainly the only solution to this problem. Difference between colors of two images can be an important metric to measure their similarity or dissimilarity. Content-based Image Retrieval is all about generating signatures of images in database and comparing the signature of the query image with these stored signatures. Color histogram can be used as signature of an image and used to compare two images based on certain distance metric.
This paper dispenses a consensus approach in digital photography to yield a better visual quality image by merging image pairs. Guided image filter is employed in this work at the acquisition level to transfers the structures and fine details of the guidance image to the filtering output along with restoration of details and fine structures in the image. The proposed synthesis approach carry out sub-band decomposition of denoised (flash and no-flash) images processed via guided filtering using 2D-DWT. The wavelet coefficients are then synthesized by using max-max decision rule. Simulations are carried out on flash/noflash image pairs contaminated with different levels of additive Gaussian noise and are evaluated on the basis of a no-reference image quality parameter. Significant improvement in quality of the synthesized image has been perceived in comparison to original ones. Index Terms-Flash image, No-flash image, Guided image filter, Discrete Wavelet Transform (DWT).
Digital photography provides a quick and facile means to capture a pair of images i.e. flash and no-flash image. Digital images are often superimposed by noises at the acquisition stage depending upon the availability of lighting. Image denoising is a key technology to reduce the noise levels from the images while preserving the fine details and structures. Predominantly, conventional Bilateral filter is employed, providing better noise reduction capabilities with low noise density while preserving the edges. The spatial processing of pixels is reckoned by using a Gaussian function (symmetric and smoothly decaying function). This paper introduces a Bilateral filter which incorporates a Rayleigh distribution function in its domain filter to smoothen out the image pairs more effectively. This filter has been implemented on both the images (flash and no-flash) in the present work. Simulations are carried out on the images contaminated with different levels of Gaussian noise and are evaluated on the basis of Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity (SSIM) as image quality parameters. Performance of the proposed filter has shown significant results when compared to the conventional Bilateral filter.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.