A NOVEL CONTRAST ENHANCEMENT ALGORITHM USING HSV COLOR SPACE
A. Gnana Pradeep, M. Gnanapriya · IJITR International Journal of Innovative Technology and Research - IJITR International Journal of Innovative Technology and Research · 2016
The goal of contrast enhancement is to provide a more appealing image.Histogram equalization (HE) is a nonlinear technique for adjusting the contrast of an image using its histogram.Conventional contrast enhancement techniques often fail to produce satisfactory results for low-contrast images and cannot be automatically applied to different images because processing parameters must be specified manually to produce satisfactory results for a given image.This paper proposes a contrast enhancement technique to enhance color images captured under poor illumination and varying environmental conditions.First images are converted from RGB to HSV color space where enhancement is achieved and reconverted to the RGB.Class Limited Adaptive Histogram Equalization (CLAHE) is used to enhance the luminance component (V).Discrete Wavelet Transform (DWT) is applied to the Saturation(S) components, and the decomposed approximation coefficients are modified by a mapping function derived from scaling triangle transform.Inverse Wavelet transform is used to obtain the enhanced S component.The image is then converted back to the RGB color space.The parameters Peak-signal-to-noise ratio (PSNR), Absolute Mean Brightness Error (AMBE) and Mean squared error (MSE) were used for performance evaluation.The algorithm implemented in MATLAB was tested and compared with outputs of Histogram Equalization and CLAHE enhancement techniques.The result shows that the new algorithm gave the best performance among the others.