| 摘要 |
PURPOSE:To improve encoding efficiency and to reduce errors in transmission by encoding while switching the part of the dither image into a one-dimensional code and a direct code, in the encoding device of an image signal which contains a dither image. CONSTITUTION:The light and shade of an original image 4 is projected on a sensor 2 through a lens 2 and then transduced into a luminance signal. This luminance signal is compared with a value generated by a dither pattern generating circuit 1 to obtain an image signal, which is encoded by a two-dimensional encoding circuit 6 and a one-dimensional encoding circuit 7 respectively. According to the contents of a counter 11 updated by one for every scanning line, a control circuit 10 switches a switch 16 to select a one-dimensional code or two-dimensional code, which is sent out to a transmission line 14 through a memory 12 and a modem 13. A dither part detecting circuit 9 detects the thickness of an image signal and when a dither image is discriminated, the counter 11 is reset. The control circuit 10 switches the switch 16 to select the direct code of a direct encoding circuit 8. |
