Multi-resolution image signal processing apparatus and method

In an apparatus for processing image signals derived by raster scanning original images, the combination of:

• p1 (a) a low resolution scanning array having plural scanning elements for viewing relatively large areas of said original images and producing image signals representative of the image areas viewed;
• (b) first image signal processing means for processing image signals produced by said low resolution array to provide binary level image signals;
• p1 (c) a high resolution scanning array having plural scanning elements for viewing relatively small areas of said original images and producing image signals representative of the image areas viewed;
• (d) second image signal processing means for processing image signals produced by said high resolution array to provide binary level image signals;
• and
• (e) control means for selecting the output of one of said first and second image signal processing means.

In a multi-resolution image scanning apparatus, the combination of:

• a first linear array for scanning one line of said image;
• a second linear array for scanning plural lines of said image;
• and
• means for substantially centering the viewing area of said first array with the viewing area of said second array whereby said first and second arrays scan in overlapping fashion to produce image pixels of different resolution.

A method of processing image signals derived by raster scanning document originals, the steps comprising:

• (a) scanning said originals at low resolution and at high resolution simultaneously to produce streams of low resolution and high resolution image signals concurrently;
• (b) independently processing said streams of low and high resolution image signals to provide binary level image signals;
• and
• (c) selecting one of said streams of low and high resolution binary level image signals in accordance with the imaginal content of the original being scanned.