Color Correction Using a Still Camera for Images Projected onto a Light Colored Screen

摘要

Recently, projectors have become among the most common display devices not only for presentations at offices and in classes, but also for entertainment at home and in the theater. The use of mobile projectors expands applications to meetings in the field and presentation anywhere. Accordingly, projection is not always guaranteed to occur on a white screen, thereby introducing the possibility of some color distortion. In this article a general color correction method using a still camera as a convenient measuring device is proposed in order to match the colors between projections on white and light colored screens. The color correction is implemented using the proposed matrix which converts the input color to the resulting color appropriate for the colored screen. The proposed color correction matrix is estimated by linear regression using input digital values measured on the white and colored screens, thereby producing the same color on both the white and light colored screens. In addition, the calibration image contains information for nine steps in each color channel, enabling accurate construction of the transform matrix. In experimental results, the proposed method gives better color correction for both the objective and subjective evaluations than does a representative previous method.