Contrast enhancement by object based Histogram Equalization

Abstract

Contrast enhancement techniques are used for improving visual quality of low contrast images. Histogram Equalization (HE) method is one such technique used for contrast enhance nt. As conventional HE processes the whole image, it may cause ill-effects such as washed out appearance and false contouring due to the significant change in brightness. So HE is not suitable for consumer electronic products directly. This paper proposes a variant of histogram equalization that tries to identify foreground and background pixels of an image and performs bi-histogram equalization on the means of them. The proposed method enhances the standard test images better than the methods available in the literature and has been validated by the performance measures like psnr,contrast and tenengrad.

A method of line spectrum extraction based on target radiated spectrum feature and its post-processing

“…Assume the line spectrum is x dB higher than the continuous spectrum. According to Sub-section 3.1 and -Sub-section 3.2, the input SNR of the wideband energy integration method is derived from (19) by simplifying (18). The input SNR of the assumed known line spectrum method also can be derived from (18), that is .…”

Performance Evaluation of HE, AHE and Fuzzy Image Enhancement

“…We determined that the color uniqueness of the secondary part of the tumors appreciably manipulates the color normalization and established that the developed normalization filter achieved acceptable normalization presentation the same as evaluated by a cross-validation test. Roomi and Prabhu et al [6] provided that for better visualization of low contrast images contrast enhancement method has been used. Histogram equalization used for Contrast enhancement.…”