Abstract: A clock synthesizing circuit for generating clock signals for driving a pixel-based image sensor includes a pixel rate generator that generates a master clock having a master clock frequency corresponding generally to a readout rate of the image sensor, a frequency locked loop that receives the master clock and generates a high frequency clock operating at a multiple of the master clock frequency, and a clock generation circuit that utilizes the high frequency clock to generate a plurality of low frequency clock signals for driving the image sensor. The frequency locked loop may be either a phase locked loop or a delay locked loop, and the clock generation circuit would utilize the edge transitions of the high frequency clock to generate the low frequency clock signals for driving the image sensor.

Abstract: A smear correction circuit for elimination of smear error within image sensing devices wherein image receiving means receive CCD image data, a determination of a smear scaling factor for smear estimation is made, the smear scaling factor being determined by a ratio of smear error per given level of illumination. The smear estimation means provide for the determining of a value for smear estimation on a per line basis. Adjustment of the image data is made corresponding to the smear estimation and dark level correction values prior applying the adjusted data to gain adjustment circuitry.

Abstract: A method and apparatus for on-line evaluation of bar code symbol quality is disclosed in which bar code decoding and evaluation functions are integrated within a single unit. The integration of the bar code decoding and evaluation functions results in significantly more conclusive analysis of the quality of the bar code symbols as the analysis methodology and decoding process utilize a common scanning device. Thus, the ambiguities associated with hardware differernces between the decoding apparatus and stand alone bar code verifiers in evaluating the quality of the bar code symbols associated with conventional evaluation techniques are eliminated.