Image scanner with real time pixel resampling

Abstract

In an image scanner, rectification of sensor data is computed in real time, so that sensor data do not need to be stored into an image memory. As a result, performance is improved because firmware for sensor data storage and retrieval is eliminated, and fewer devices are arbitrating for access to the image memory. The rectification system is extendable to color scanning by providing one rectification module for each color. In various example embodiments, sensor data are entered into a data buffer configured as a first-in-first-out buffer. The buffer is sufficiently long to hold a little more than one scan-line of data. In a first example embodiment, an interpolator module receives sensor data from fixed locations within the buffer. As new values are entered, old unneeded values are simply discarded. Some special conditions require a distinctive (for example, blank or null) value to be inserted to maintain proper data alignment within the buffer. Some special conditions require a value to be discarded to maintain proper alignment. In a second example embodiment, a multiplexer is used to select values from variable positions within the data buffer.