1. A processor-implemented method for processing image data in an image processing apparatus, the image processing apparatus comprising at least one processor for processing documents containing image data comprising a plurality of pixels, the method comprising the following acts implemented by the at least one processor: receiving a page description language file of image data comprising a plurality of pixels and related image instructions; raster image processing the page description language file to create a bitmap file with a first data structure indicating at least pixels representing text; segmenting the bitmap file to determine at least pixels in the bitmap file representing text not indicated in the first data structure to form a second data structure, and combining the first data structure and the second data structure to form a third data structure indicating locations for marking substantially colorless marking material onto a substrate using an image output device.