To provide a technique for correcting a target pixel with high accuracy.SOLUTION: An image processing apparatus includes: an acquisition unit which acquires a radiation image including a correction target pixel； a calculation unit which calculates, for the correction target pixel, each priority in two mutually intersecting directions； and a determination unit which allocates a large weight to the pixel value of a pixel in the direction having high priority to the correction target pixel, whereas allocates a small weight to the pixel value of a pixel in the direction having low priority to the correction target pixel, so as to determine the pixel value of the correction target pixel. When the direction of the calculation target out of the two directions is a first direction, and the other direction is a second direction, when calculating each priority in the two directions, the calculation unit uses the pixel values of a plurality of pixels which include a first pixel adjacent to the correction target pixel, a second pixel adjacent to the first pixel in the first direction, and a third pixel opposite to the first pixel or the second pixel to a straight line which extends in the second direction through the correction target pixel.SELECTED DRAWING: Figure 6【課題】対象画素の補正を精度良く行うための技術を提供する。【解決手段】画像処理装置は、補正対象画素を含む放射線画像を取得する取得部と、補正対象画素について、互いに交差する２つの方向のそれぞれの優先度を算出する算出部と、補正対象画素に対して優先度が高い方向にある画素の画素値に大きい重みを割り当て、補正対象画素に対して優先度が低い方向にある画素の画素値に小さい重みを割り当てることによって、補正対象画素の画素値を決定する決定部とを備え、算出部は、２つの方向のそれぞれの優先度の算出において、２つの方向のうち算出対象の方向を第１方向とし、他方の方向を第２方向とした場合に、補正対象画素に隣接した第１画素と、第１方向において第１画素に隣接した第２画素と、補正対象画素を通り第２方向に延びる直線に対して第１画素又は第２画素の反対側にある第３画素とを含む複数の画素の画素値を用いる。【選択図】図６
