RESUMEN
In sand-dust environments, the low quality of images captured outdoors adversely affects many remote-based image processing and computer vision systems, because of severe color casts, low contrast, and poor visibility of sand-dust images. In such cases, conventional color correction methods do not guarantee appropriate performance in outdoor computer vision applications. In this paper, we present a novel color correction and dehazing algorithm for sand-dust image enhancement. First, we propose an effective color correction method that preserves the consistency of the chromatic variances and maintains the coincidence of the chromatic means. Next, a transmission map for image dehazing is estimated using the gamma correction for the enhancement of color-corrected sand-dust images. Finally, a cross-correlation-based chromatic histogram shift algorithm is proposed to reduce the reddish artifacts in the enhanced images. We performed extensive experiments for various sand-dust images and compared the performance of the proposed method to that of several existing state-of-the-art enhancement methods. The simulation results indicated that the proposed enhancement scheme outperforms the existing approaches in terms of both subjective and objective qualities.
RESUMEN
Single image dehazing has been a challenging problem because of its ill-posed nature. For this reason, numerous efforts have been made in the field of haze removal. This paper proposes a simple, fast, and powerful algorithm for haze removal. The medium transmission is derived as a function of the saturation of the scene radiance only, and the saturation of scene radiance is estimated using a simple stretching method. A different medium transmission can be estimated for each pixel because this method does not assume that transmission is constant in a small patch. Furthermore, this paper presents a color veil removing algorithm, which is useful for an image with fine or yellow dust, using the white balance technique. The proposed algorithm requires no training, prior, and refinement process. The simulation results show that the proposed dehazing scheme outperforms state-of-theart dehazing approaches in terms of both computational complexity and dehazing efficiency.
RESUMEN
Although the Work Ability Index (WAI) has been used in many countries, its reliability is yet to be validated in Korea. In our study, test-retest results of WAI total score, WAI category and seven subscales were compared. The correlation coefficients of WAI total score and subscales 1 and 2 between test and retest were 0.70, 0.80 and 0.63, respectively. The κ values on WAI category, subscales 4, 5, 6 and 7 were 0.52, 0.32, 0.31, 0.48 and 0.85, respectively. The results of our reliability test show that WAI scores of female, younger and private company workers were found to be higher than those of male, older and public company workers, respectively. We conclude that overall test-retest reliability of WAI in Korea is acceptable. Another notable observation from our study is that work ability dimension (subscales 1, 2 and 7) had a higher reliability, whereas health dimension (subscales 3-6) had a lower reliability.
