1. An image processing apparatus comprising: a processor configured to operate as: an acquisition unit configured to acquire original image data expressing an original image that comprises a first type pixel and a second type pixel; and an enlargement processing unit configured to execute enlargement processing for the original image data to generate enlarged image data expressing an enlarged image that is obtained by enlarging the original image in a first direction, wherein the enlargement processing unit comprises: a pixel group selection unit configured to select a pixel group extending in a second direction intersecting with the first direction in the enlarge image when a specific pattern configured by the first type pixel and the second type pixel is included in the original image, wherein the pixel group in the enlarged image comprises: a corresponding specific pixel corresponding to a specific pixel in the original image; and a pixel positioned in the second direction of the corresponding specific pixel, wherein the specific pixel in the original image is a pixel corresponding to the specific first type pixel configuring the specific pattern, and wherein the number of pixels configuring the pixel group in the enlarged image being a number corresponding to a first continuous number and a second continuous number, the first continuous number being a number that a first pattern continues from the specific pixel toward the second direction in the original image, and the second continuous number being a number that a second pattern continues from the specific pixel toward an opposite direction to the second direction; and a setting unit configured to set a pixel configuring the pixel group in the enlarged image as the second type pixel.