| 摘要 |
PROBLEM TO BE SOLVED: To process an optimum image in the situation of a wide range and to always obtain appropriate distance information. SOLUTION: The histogram of luminance and the histogram of luminance change quantity in a horizontal direction are generated from data of an original image in CPU for recognition processing 29. A luminance value at which the number of data becomes a rate that an area where distance data is considered to exist is calculated from the histogram of luminance. Electronic switch circuits 17 and 18 are switched by the luminance value and LOG correction is turned on/off. Luminance change quantity at which the rate of the number of data becomes not more than the luminance difference appropriate for calculating the distance is calculated form the histogram of luminance change quantity. It is transferred to luminance change validity judgment circuit 25 as a threshold for judging whether data of VRAM 21 is valid or not for calculating distance information. A distance information validity judgment circuit 26 judges the validity of distance information by the judgment result of the luminance change validity judgment circuit 25. Thus, an appropriate image processing can be executed in a situation where a contrast is small such as a snowy road. |
