1. A method for halftoning image data for a targeted one of plural pixels, comprising the steps of: testing to determine whether high frequency spatial characteristics are present in the image data at the target pixel; selecting a halftoning threshold for the target pixel, the halftoning threshold being selected based on whether high frequency spatial characteristics are present at the target pixel, and further being selected in accordance with intensity of the image data at the target pixel in a case where high frequency spatial characteristics are not present; determining a halftone output value for the target pixel based on a comparison between the selected threshold and the image data for the target pixel; and diffusing error between the halftone output value and the image data for the target pixel, the error being diffused to pixels adjacent the target pixel.