Abstract
We believe that there is a preferred tone reproduction for each painting or drawing similarly to a photograph. In the present paper, a preferred tone reproduction for line drawing was investigated and it was compared with that for the photograph. Lightness of line drawing is controlled by area modulation and its tone is discrete differently from photograph. Line drawings were prepared from photographs, contour was obtained by using the high-pass filter after smoothing through the bilateral filter, and then the continuous tone of photograph was divided into equilightness regions with 7-8 lightness unit interval. To each region a tone patch of diagonal stroke with the same lightness as it was applied. The results of subjective evaluation showed that the preferred tone reproduction is different between line drawing and photograph and also between portrait and landscape picture.
