Abstract: What is disclosed is a novel system and method for detecting and correcting for In-Line-Spectrophotometer (ILS) measurements of constant value patches in the presence of banding in multi-function document reproduction systems. The present system analyzes the ILS data stream to identify structured noise components due to banding. An FFT is performed on each L*a*b* component in the ILS stream for a single test page. The peak frequencies from the FFT of the L* a* and b* channels are compared. Common frequencies in all 3 channels indicate a banding component. Once the banding frequencies and the banding wavelength are known, the color patch target can be adjusted to ensure the color patches are synchronized to the banding wavelength. By running a series of synchronized patches and averaging results, structured noise can be eliminated. In such a manner, a reduction of banding effects on color calibration can be effectuated.

Abstract: What is disclosed is a novel system and method for detecting and correcting for In-Line-Spectrophotometer (ILS) measurements of constant value patches in the presence of banding in multi-function document reproduction systems. The present system analyzes the ILS data stream to identify structured noise components due to banding. An FFT is performed on each L*a*b* component in the ILS stream for a single test page. The peak frequencies from the FFT of the L* a* and b* channels are compared. Common frequencies in all 3 channels indicate a banding component. Once the banding frequencies and the banding wavelength are known, the color patch target can be adjusted to ensure the color patches are synchronized to the banding wavelength. By running a series of synchronized patches and averaging results, structured noise can be eliminated. In such a manner, a reduction of banding effects on color calibration can be effectuated.