HALFTONING AT MULTIPLE DIFFERENT RESOLUTIONS

Multi-resolution halftoning to process image data by determining whether the image data corresponds to black image data or color image data, performing a halftoning process of a first resolution on the black image data, performing a halftoning process of a second resolution on the color image data, and performing a smoothing process on the black image data. The first resolution may be a low resolution and the second resolution may be a high resolution and the black image data may be expanded into high resolution data. Image data subjected to multi-resolution halftoning may be printed by a print head with black nozzles having a faster printing speed than color nozzles.