A lane recognition image processing apparatus can improve lane marking recognition performance by preventing false detection by addition of a condition without changing the basic principle of an one-dimensional image filter. A search area is set for each lane marking with respect to images stored in a image storage part through a window. A candidate point extraction part extracts candidate points of each lane marking from the search area thus set. A lane marking mathematical model equation is derived by approximating sets of extracted candidate points by a mathematical model equation. The candidate point extraction part includes a kernel size setting part, a filtering part that outputs, as a filtering result, the smaller of differences between the gray value of a pixel of interest and those of pixels forwardly and rearwardly apart a kernel size from the pixel of interest in a scanning direction, respectively, and a binarization part that binarizes the filtering result.