Enhanced fog detection and free-space segmentation for car navigation

Abstract

Free space detection is a primary task for car navigation. Unfortunately, classical approaches have difficulties in adverse weather conditions, in particular in daytime fog. In this paper, a solution is proposed thanks to a contrast restoration approach on images grabbed by an in-vehicle camera. The proposed method improves the state of the art in several ways. First, the segmentation of the fog region of interest is better segmented thanks to the computation of shortest routes maps. Second, the fog density as well as the position of the horizon line are jointly computed. Then, the method restores the contrast of the road by only assuming that the road is flat and, at the same time, detects the vertical objects. Finally, a segmentation of the connected component in front of the vehicle gives the free space area. An experimental validation was carried out to foresee the effectiveness of the method. Different results are shown on sample images extracted from video sequences acquired from an in-vehicle camera. The proposed method is complementary to existing free space area detection methods relying on color segmentation and stereovision.

Fast Fog Detection for De-Fogging of Road Driving Images

“…(1) from Duntainy attenuation law according to the International Commission on Illumination (CIE) that the contrast of the object should be higher than 5%. [11], [12]. Hautiere et al's method estimated the depth by modeling the environment in which the camera is installed [11].…”

“…[11], [12]. Hautiere et al's method estimated the depth by modeling the environment in which the camera is installed [11]. Mao et al estimated the fog factor and detected fog using the property that the difference between the maximum value and the minimum value of the RGB color channel is larger as the fog becomes darker [12].…”

Persistent exersize on foggy image

“…A number of ways are selecting to define the type of fog that may depend to the concentration of cold occurrence. [10][11][12] The formation of rradiation fog is depends on the cooling of atmosphere after sunset by thermal radiation. [4][5] One more types of fog depending o sky is ground fog and measured in the 60% probability of sky affects.…”

Single image fog removal based on local extrema

“…In the next experiments, we employ the database named FRIDA2 [17] for the evaluation of the proposed method under the ideal condition. FRIDA2 is available for research purpose and in particular to allow other researchers to rate their own visibility enhancement methods.…”

“…This database provides 66 images of the same virtual scene with and without fog. The proposed method will be compared with 5 other methods [17] : multi-scale retinex (MSR), adaptive histogram equalization (CLAHE), free space segmentation (FSS), noblack-pixel constraint (NBPC) [8] and dark channel prior (DCP) [6] .…”