Automatic image segmentation with smoothing

Claim 1

In a digital image processing system providing circuits for processing a digital image in accordance with one of a plurality of image types in accordance with an image type detection signal received at an image processing controller, a method for improving uniformity in image type detection, the steps comprising: receiving from an image source a document image represented in a digital image signal format, having an unknown combination of the image types in the document image, and storing digital image signals representing an area of the document image in a data buffer; with an image segmentation circuit, receiving digital image signals from the data buffer and determining image types present in an area of the document image therefrom, said image segmentation circuit producing a detection signal for each digital image signal representing the image type at a corresponding location within the image; converting the detection signals into a plurality of binary signals, each binary signal representing detection or non detection of a single image type; for binary detection signals of a single image type, providing a first filter processing said binary detection signals to provide a first state thereof whenever all the binary detection signals in a predetermined set thereof have a first state, and producing a first filtered binary detection signal indicative thereof; for each binary detection signal of a single image type, providing a second filter, processing said first filtered binary detection signal to provide a first state thereof whenever any of the first filtered binary detection signals in a predetermined set thereof have a first state and producing a second filtered binary detection signal; directing said second binary filtered detection signals to the image processing controller to control the circuits for processing plural image types in accordance with the determined image type.