Patent ID: 11881026
Assignee: THE SEOUL INSTITUTE
Field: Computer technology (Electrical engineering)
Classification: CPC G  Y | IPC G

Claim 0:
1. A nighttime road fog detection system comprising:
at least one processor configured to:
(i) search for and collect image signals obtained by photographing a road to be monitored from one or more closed-circuit television (CCTV) cameras installed at respective points on the road to be monitored in real time;
(ii) use a fog detection algorithm to determine edges of fog appearing in the image signals and identify a fog region from the determined edges;
(iii) extract red (R), green (G), and blue (B) color information for each pixel of the image signals from edges of the identified fog region, generate a mapping image including a masking region using the R, G, and B color information, superimpose the mapping image on the image signals, and output the image signals on which the mapping image is superimposed;
(iv) compare the R, G, and B color information with reference color information and set a nighttime threshold value for determining day or night; and
(v) remove a masking region corresponding to a whitened region generated by an external light source at night from the mapping image on the basis of the nighttime threshold value for each of the points at which the CCTV cameras are installed,
wherein step (v) detects R, G, and B color information of the fog region to assign X and Y coordinates to the fog region, classifies a region of the fog region, in which the X and Y coordinates are not changed for more than a certain period of time, as a fixed light source, and classifies a region of the fog region, in which the X and Y coordinates are changed, as a moving light source, and
wherein, when the fixed light source appears in the image signal, step (v) removes a masking region corresponding to the fixed light source from the mapping image, generates an Nth frame (N is a natural number), and sets an (N+1)th frame to be the same as the Nth frame.