1. A method for quantizing image data, comprising the steps of: retrieving image data for a selected pixel of an image; determining whether the selected pixel lies within a highlight or shadow region of the image; detecting whether another pixel within a predetermined distance of the selected pixel has a quantized value representative of a dot that is complementary to the determined region of the image, when the selected pixel is determined to be in a highlight or shadow region of the image; quantizing the image data for the selected pixel to a value representative of a dot that is complementary to the determined region of the image if no other pixel within said predetermined distance has a quantized value representative of a dot that is complementary to the determined region of the image; and otherwise quantizing the image data for the selected pixel to a value associated with the determined region of the image.