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原帖由 kaiyuanyinwu 于 2010-11-20 09:11 发表
谢谢你的指导,我分别降低 "Brightness"到0.8、0.6、0.3(默认是1.0)实验了下,图片背景灰度在0.8的情况下稍微有点(0.6和0.3情况下比0.8还浅),但是还是不正,表现在三方面:1、灰度浅;2、横着的 ...
我觉得是不是可以尝试调整Gutenprint中的Gray Generation Controls参数试试看。
用户手册上是这么说的:
These controls adjust the conversion of gray into black ink and composite (CMY) components.
When printing in color, light grays are often printed using composite inks rather than black ink
to reduce the speckling effect of dark black dots, while dark grays and black are usually printed
using black ink to achieve a darker black. With some ink and paper combinations it is necessary
to use a mixture of black and composite components to achieve maximum density and in some
cases to achieve neutral grays (some pigment black inks are actually brown).
The effect of using too much or too little black ink varies. Typically if too much black ink is
used light colors and grays will have noticeable speckling from the black drops, while if too
little black ink is used the midtones and dark tones will be washed out and in some cases too
much ink will be used leading to puddles on the page. In some cases very large amounts of
composite ink cause color shifts (darker grays are not neutral). Epson Premium Glossy Photo
Paper seems to be particularly prone to this problem, particularly with dye inks.
In general, lower-quality papers require more black ink (composite inks generally cannot create
very dark tones), while higher quality papers require less black ink (the composite inks can
create much darker grays, and the black dots appear much sharper).
Setting these controls effectively requires a good understanding of gray generation and a fair
amount of experimentation. Normally it's only necessary to set the paper type correctly to get
good results.
These options are all new to Gutenprint 5.0. |
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