Image analysis counting system

A system for obtaining a count of overlapped newspapers having side edges carried on a moving conveyor comprising,

• a linear CCD array oriented transversely of the side edges of said newspapers for optically focusing the side image of said newspapers on said linear CCD array,
• means for continuously serially shifting outputs from said photodetector array at a clock defined rate,
• signal processing means for receiving said serially shifted outputs from said linear CCD array,
• said signal processing means comprising means for developing clock defined repetitive sequential digital values definitive of the top profile of said newspapers as said newspapers are conveyed past said linear CCD array,
• means for comparing each of said digital values with the next preceding one of said digital values to obtain derivative value of the top profile of said newspapers,
• means for initiating a newspaper count output increment when said derivative value change from positive to negative,
• means to develop a newspaper thickness definite value from a comparison between the previous newspaper top profile and the existing newspaper top profile value, and difference value calculated from sample to sample changes from positive to negative of the existing newspaper, said newspaper count output comprising a single count increment when said newspaper thickness definitive value exceeds a calibrated value thickness, and said newspaper count output comprising a double count increment when said newspaper thickness value exceeds a second calibrated value thickness.

A method of obtaining a count of overlapped newspapers carried on a moving conveyor by image analysis of the image of the side edges of said newspaper as the focused image impinges on a linear CCD array oriented transversely of said newspaper side edges, comprising the repetitive sequential steps of:

• serially shifting analog outputs from the linear CCD array and a reference light level output to a differential amplifier to remove the D.C. offset therefrom, amplify and filter high frequency noise therefrom;
• converting the analog output signal from said differential amplifier to a serial digital output signal as defined by a selected light level;
• applying said serial digital output to a serial in/parallel out shift register;
• storing the parallel output from said shift register in a random access memory;
• transferring data in said random access memory to a microprocessor for developing a value definitive of the top profile of the newspaper image as it appears on the photodetector array;
• obtaining the difference between successive newspaper image top definitive value to obtain a value definitive of the rate of change of said top definitive values;
• determining the thickness of the newspapers when the rate of change of said top definitive value changes from positive to negative;
• initiating a single count increment when the rate of change of successive top definitive counts goes from positive to negative and the measured thickness of the newspapers exceeds a first calibrated value thickness;
• and
• initiating a double count increment when the rate of change of successive top definitive values changes from positive to negative and the measured thickness of the newspapers exceeds a second calibrated value thickness.