An image information processing apparatus configured to determine a region suitable for adjusting the image forming performance of an image forming apparatus, the image information processing apparatus comprising: a segment region extraction unit configured to extract a segment region from an entire region of the acquired image data; an evenness degree calculation unit configured to calculate an evenness degree that shows density evenness based on pixel values of the segment region; a color purity calculation unit configured to calculate color purity for color information of the segment region; a quality determination unit configured, with respect to all segment regions of the image data, to determine the segment region as an excellent segment regions if the evenness degree and the color purity are equal to or are greater than or equal to respective predetermined thresholds; a candidate region selection unit configured to select, as a candidate region, a region that has a number of the excellent segment regions from among the entire region of the image data based on positional information of the excellent segment regions; a combination specification unit configured to select a predetermined number of the segment regions from all the segment regions included in the candidate region, and to specify different combinations cf the segment regions; a spatial dispersion degree calculation unit configured to calculate the spatial dispersion degree of the segment regions on the basis of all possible combinations of the segment region; an index value calculation unit configured to calculate an index value by summing up the evenness degrees of the segment regions multiplied by a first weighting coefficient, the color purities of the segment regions multiplied by a second weighting coefficient, and the spatial dispersion degree multiplied by a third weighting coefficient on the basis of all the possible combinations of the segment region; and an object region determination unit configured to determine, as an object region, the segment regions that correspond to the largest one of the index values. a segment region extraction unit configured to extract a segment region from an entire region of the acquired image data; an evenness degree calculation unit configured to calculate an evenness degree that shows density evenness based on pixel values of the segment region; a color purity calculation unit configured to calculate color purity for color information of the segment region; a quality determination unit configured, with respect to all segment regions of the image data, to determine the segment region as an excellent segment regions if the evenness degree and the color purity are equal to or are greater than or equal to respective predetermined thresholds; a candidate region selection unit configured to select, as a candidate region, a region that has a number of the excellent segment regions from among the entire region of the image data based on positional information of the excellent segment regions; a combination specification unit configured to select a predetermined number of the segment regions from all the segment regions included in the candidate region, and to specify different combinations cf the segment regions; a spatial dispersion degree calculation unit configured to calculate the spatial dispersion degree of the segment regions on the basis of all possible combinations of the segment region; an index value calculation unit configured to calculate an index value by summing up the evenness degrees of the segment regions multiplied by a first weighting coefficient, the color purities of the segment regions multiplied by a second weighting coefficient, and the spatial dispersion degree multiplied by a third weighting coefficient on the basis of all the possible combinations of the segment region; and an object region determination unit configured to determine, as an object region, the segment regions that correspond to the largest one of the index values.