公开(公告)号：US5802209A

公开(公告)日：1998-09-01

申请号：US672044

申请日：1996-06-26

申请人： Toshiyuki Hattori ,  Ryuji Oomoto ,  Kiyoaki Murai

发明人： Toshiyuki Hattori ,  Ryuji Oomoto ,  Kiyoaki Murai

IPC分类号： B41J2/52 ,  B41J2/485 ,  G06F3/12 ,  G06T9/00 ,  H04N1/405 ,  H04N1/41 ,  G06K9/00

CPC分类号： H04N1/4056 ,  H04N1/4105

摘要： When an N-times density binary image having N+1 tones is compressed, only the tone of each pixel is converted into a compressed code. The compressed code has a number of bits necessary and sufficient to distinguish between the tones. When a triple-density image having 4 tones is compressed, for example, the tone of each pixel is converted into a 2-bit compressed code. When the original N-times density is restored from the compressed code, there is formed a dot pattern in which the number of dots corresponding to the tone, as represented by the compressed code of each pixel, are situated closer to the darker one of the two adjoining pixels.

摘要翻译： 当压缩具有N + 1个音调的N倍密度二进制图像时，仅将每个像素的色调转换为压缩码。 压缩码具有必要和足以区分色调的位数。 当压缩具有4个音调的三重密度图像时，例如，每个像素的色调被转换成2位压缩码。 当从压缩码恢复原始的N倍密度时，形成一个点阵图形，其中由每个像素的压缩码表示的与色调对应的点数位于更接近于 两个相邻的像素。

公开(公告)号：US5621543A

公开(公告)日：1997-04-15

申请号：US495193

申请日：1995-06-27

申请人： Ryuji Oomoto

发明人： Ryuji Oomoto

IPC分类号： G06T9/00 ,  H03M7/30 ,  H03M7/40 ,  H04N1/41 ,  H04N1/40

CPC分类号： H04N1/4105

摘要： In the case of a 4-fold density image, for example, 2-pixel areas in the 4-fold density image which are adjacent to each other are allocated with one 4-bit compression code, respectively. In this case, the possible patterns which can be produced by the 8-dot pattern of the 2-pixel area are limited to 16 kinds of patterns in which there is one or less black and white change. With respect to 2-bit portions of 4-bit compression codes which correspond to pixels, correspondence relationships between 2-bit portions and 4-dot patterns are set so that, when a 2-bit portion is inverted or converted into "11" in all bits or "00" in all bits, also the 4-dot pattern of the corresponding pixel is similarly inverted or converted into a pattern of all white dots or all black dot. Next, by combining the correspondence relationships of the 2-bit portions, 12 kinds of correspondence relationships between 4-bit compression codes and 8-dot patterns of two pixels are produced. With respect to four dot patterns to which the relationships cannot be applied, furthermore, relationships between the patterns and compression codes are set so that, when a compression code is inverted, also the 8-dot pattern is inverted. A 4-fold density image is represented by using the 16 kinds of compression codes.

摘要翻译： 在4倍密度图像的情况下，例如，彼此相邻的4倍密度图像中的2像素区域分别被分配有一个4位压缩码。 在这种情况下，可以通过2像素区域的8点图案产生的可能图案被限制为存在一个或更少的黑白变化的16种图案。 对于与像素相对应的4位压缩码的2位部分，2位部分与4点图形之间的对应关系被设定为使得当2位部分被反转或转换成“11”时 所有位中的所有位或“00”，相应像素的4点图案也相似地反转或转换成所有白点或全部黑点的图案。 接下来，通过组合2位部分的对应关系，产生4位压缩码和2个像素的8点图案之间的12种对应关系。 对于不能应用关系的四个点图案，此外，设置图案与压缩码之间的关系，使得当压缩码反转时，8点图案也被反转。 使用16种压缩码表示4倍密度图像。