A lens dirtiness detection apparatus configured to detect a transparent lens dirtiness of a camera, comprising: a control unit; and a memory coupled to the control unit, wherein the memory stores therein pixel value data of an image captured by the camera, and wherein the control unit is characterized in that it is configured to: divide the image into a plurality of first regions of a predetermined image size; calculate image frequency powers for each of the plurality of first regions of the image based on pixel value data of the pixels situated within the corresponding first region; calculate the average image frequency power for each of the plurality of first regions of the image based on the image frequency powers calculated for the corresponding first region; determine whether each of the average image frequency powers of the plurality of first regions exceeds a predetermined first threshold or not; determine presence of a transparent lens dirtiness of the camera if the number of the first regions in which the image frequency power does not exceed the first threshold value exceeds a predetermined second threshold and otherwise determine absence of a transparent lens dirtiness of the camera; and output the determination result on presence or absence of a transparent lens dirtiness. a control unit; and a memory coupled to the control unit, wherein the memory stores therein pixel value data of an image captured by the camera, and wherein the control unit is characterized in that it is configured to: divide the image into a plurality of first regions of a predetermined image size; calculate image frequency powers for each of the plurality of first regions of the image based on pixel value data of the pixels situated within the corresponding first region; calculate the average image frequency power for each of the plurality of first regions of the image based on the image frequency powers calculated for the corresponding first region; determine whether each of the average image frequency powers of the plurality of first regions exceeds a predetermined first threshold or not; determine presence of a transparent lens dirtiness of the camera if the number of the first regions in which the image frequency power does not exceed the first threshold value exceeds a predetermined second threshold and otherwise determine absence of a transparent lens dirtiness of the camera; and output the determination result on presence or absence of a transparent lens dirtiness. divide the image into a plurality of first regions of a predetermined image size; calculate image frequency powers for each of the plurality of first regions of the image based on pixel value data of the pixels situated within the corresponding first region; calculate the average image frequency power for each of the plurality of first regions of the image based on the image frequency powers calculated for the corresponding first region; determine whether each of the average image frequency powers of the plurality of first regions exceeds a predetermined first threshold or not; determine presence of a transparent lens dirtiness of the camera if the number of the first regions in which the image frequency power does not exceed the first threshold value exceeds a predetermined second threshold and otherwise determine absence of a transparent lens dirtiness of the camera; and output the determination result on presence or absence of a transparent lens dirtiness.