Compensation of printer MTFs

Preliminary experiments have shown that the quality of printed images depends on the capacity of the printing system to accurately reproduce details.1 We propose to improve the quality of printed images by compensating for the Modulation Transfer Function (MTF) of the printing system. The MTF of the printing system is measured using the method proposed by Jang and Allebach,2 in which test pages consisting of series of patches with different 1D sinusoidal modulations (modified to improve the accuracy of the results3) are printed, scanned and analyzed. Then the MTF is adaptively compensated in the Fourier domain, depending both on frequency and local mean values. Results of a category judgment experiment show significant improvement as the printed MTF compensated images obtain the best scores

Measurement of printer MTFs

In this paper we compare three existing methods to measure the Modulation Transfer Function (MTF) of a printing system. Although all three methods use very distinct approaches, the MTF values computed for two of these methods strongly agree, lending credibility to these methods. Additionally, we propose an improvement to one of these two methods, initially proposed by Jang & Allebach. We demonstrate that our proposed modification improves the measurement precision and simplicity of implementation. Finally we discuss the pros and cons of the methods depending on the intended usage of the MTF