1. An image processing apparatus comprising: a processor; and memory storing computer readable instructions, when executed by the processor, causing the image processing apparatus to execute: acquiring target data representing a target image; calculating, for each of a plurality of target pixels forming the target data, a density relation value related to density of the target pixel; selecting a conversion color for an object pixel among the plurality of target pixels; converting pixel value of the object pixel to generate converted data such that, the higher the density represented by the density relation value of the object pixel, the closer the pixel value of a pixel of the converted data to a value indicative of the conversion color for the object pixel; and outputting the converted data.