In an apparatus for performing printing using a color ink-jet head having a plurality of ink-discharge-port strings corresponding to ink materials having different color tones, a high-quality image having excellent gradation can be recorded, while reducing the cost of the apparatus and increasing the data processing speed by reducing the capacity of a memory for storing dot arrangement patterns. For that purpose, as a plurality of dot arrangement patterns for determining dot arrangement at output within a M×N-dot region for one input pixel, (1) patterns having a large number of gradation levels that can be represented (for example, nine gradation levels) and a high recording resolution (for example, 1,200 dpi (dots per inch)×2,400 dpi) are used for colors in which uneven stripes tend to be pronouncedly observed (for example, light cyan and light magenta), and (2) patterns having a small number of gradation levels that can be represented (for example, five gradation levels) and a low recording resolution (for example, 1,200 dpi×1,200 dpi) are used for colors in which uneven stripes tend to be less pronouncedly observed (for example, black, cyan, magenta and yellow).