An Anisotropic Gaussian Filtering Model for Image De-Hazing

Abstract

This paper proposes a de-hazing algorithm on the basis of the anisotropic Gaussian filtering method to overcome some essential limitations of the DCP-based (the dark channel prior, DCP) methods, such as halo artifacts and over-saturation problems. In this method, the approximate range of the global atmospheric light A is obtained by using the spatial LOG edge detection method, and the accurate A is acquired by combing binary algorithm. And an anisotropic Gaussian filtering method is adopted to optimize the transmission, which can smooth the rough transmission map, improve the clarity of image details and inhibit halo artifact and over-saturation effect. With the accurate A and optimized transmission, the dehazing results can be acquired on the basis of the atmospheric scattering model. The processing effect is verified by our own fog image data set constructed in real life or downloaded from the Internet. The visual effect of our method is more natural in brightness, contrast and detail recovery. Besides, the indicators SSIM, PSNR, Lum, Con, Inf, e and r are relatively high, and indicators MSE and ɛ are relatively low. Therefore, subjective and objective experimental results demonstrate that our method outperforms four state-of-the-art methods in terms of visual sense definition, robustness and time efficiency.

Pengaruh Ukuran Jendela Ketetanggaan (Window) Terhadap Hasil Redukasi Noise pada Metode Median Filter dan Gaussian Filter

“…Gaussian filter juga berfungsi untuk menghasilkan garis tepian pada citra yang sesungguhnya. Apabila proses ini tidak digunakan maka pada pendeteksian garis garis yang halus juga akan terdeteksi menjadi garis tepian [13]. Filter gaussian dapat ditulis dengan presamaan sebagai berikut:…”

TMCD: Threshold multi-channel prior-based defogging algorithm for underground coal mine images

“…Furthermore, the accuracy of the transmission rate estimation directly impacts the subsequent image dehazing process. The atmospheric scattering model explains that as the fog concentration increases, the scattering effect of the reflected light from scene objects intensifies, leading to brighter colors in the image scene 41 . Therefore, a common practice is to consider the brightest color in the image as the global atmospheric light value.…”