tiffg4 is a black&white output device. You should use tiff24nc or tiff12nc as the output device colour PDFs - see ghostscript output devices. These will be uncompressed but you could put the resulting TIFFs through imagemagick or similar to resave as compressed TIFF.
setori's command does not specify the resolution to use for the tiffg4 output. The consequence is: Ghostscript will use its default setting for that output, which is 204x196dpi.
In order to increase the resolution to 600dpi, add a -r600 commandline parameter:
Also note that TIFFG4 is the standard fax format and as such it uses black+white/grayscale only, but no colors.
@jeff: Have you ever tried the -dDITHERPPI=<lpi> parameter with Ghostscript? (Reasonable values for lpi are N/5 to N/20, where N is the resolution in dpi. So for -r600 use try with -dDITHERPPI=30 to dDITHERPPI=120).
danio's answer is probably the best, if you need a color copy.
I notice also, from the linked thread, that you omitted to specify DPI for the output, hence the bad look... If you need pure dithered B&W, you should use a higher resolution.
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tiffg4 是黑白输出设备。
您应该使用 tiff24nc 或 tiff12nc 作为彩色 PDF 的输出设备 - 请参阅 ghostscript 输出设备。
这些将是未压缩的,但您可以将生成的 TIFF 通过 imagemagick 或类似的方式重新保存为压缩的 TIFF。
tiffg4 is a black&white output device.
You should use tiff24nc or tiff12nc as the output device colour PDFs - see ghostscript output devices.
These will be uncompressed but you could put the resulting TIFFs through imagemagick or similar to resave as compressed TIFF.
我使用 ImageMagick 已经有一段时间了。 这是一个非常好的工具,有很多功能。
安装 ImageMagick 并运行以下命令。 这是我在 Linux 上使用的,您可能需要将
convert
替换为正确的。以下命令将 PDF 转换为 CCITT Group 3 标准 TIF(传真标准):
您也可以使用 GraphicsMagick ,它也与ImageMagick类似,但ImageMagick更关注质量而不是速度。
I have been using ImageMagick for quite a sometime. It's very nice tool with a lot of features.
Install ImageMagick and run following command. This is what I used on Linux, you may have to replace
convert
with the correct one.Below command converts PDFs to CCITT Group 3 standard TIFs (Fax standard):
Also you may use GraphicsMagick, it is also similar to ImageMagick, but ImageMagick more concerns with quality than speed.
谢谢大家,这就是我的结局
Thanks guys this is what I ended up with
像建议的其他帖子一样,使用颜色格式(例如 -sDEVICE=tiff24nc)并指定更高分辨率(例如 -r600x600):
Like other posts suggested, use a color format (e.g. -sDEVICE=tiff24nc) and specify a higher resolution (e.g. -r600x600):
setori 的命令未指定用于 tiffg4 输出的分辨率。 结果是:Ghostscript 将使用该输出的默认设置,即 204x196dpi。
为了将分辨率提高到 600dpi,请添加 -r600 命令行参数:
另请注意,TIFFG4 是标准传真格式,因此它仅使用黑+白/灰度,而不使用颜色。
@jeff:您是否尝试过使用 Ghostscript 使用
-dDITHERPPI=
参数? (lpi 的合理值为 N/5 到 N/20,其中 N 是以 dpi 为单位的分辨率。因此,对于-r600
,请尝试使用-dDITHERPPI=30
到dDITHERPPI=120
)。setori's command does not specify the resolution to use for the tiffg4 output. The consequence is: Ghostscript will use its default setting for that output, which is 204x196dpi.
In order to increase the resolution to 600dpi, add a
-r600
commandline parameter:Also note that TIFFG4 is the standard fax format and as such it uses black+white/grayscale only, but no colors.
@jeff: Have you ever tried the
-dDITHERPPI=<lpi>
parameter with Ghostscript? (Reasonable values for lpi are N/5 to N/20, where N is the resolution in dpi. So for-r600
use try with-dDITHERPPI=30
todDITHERPPI=120
).对于传真来说非常好! ;-)
danio 的答案可能是最好的,如果您需要彩色副本。
我还注意到,从链接的线程中,您省略了为输出指定 DPI,因此外观很糟糕...如果您需要纯抖动黑白,则应该使用更高分辨率。
我还使用 NConvert 获得了漂亮的图像
我提及它是为了记录,因为我认为您需要许可证才能重新分发它(否则它可以免费供个人使用)。
It is quite nice for a fax! ;-)
danio's answer is probably the best, if you need a color copy.
I notice also, from the linked thread, that you omitted to specify DPI for the output, hence the bad look... If you need pure dithered B&W, you should use a higher resolution.
I also got a good looking image using NConvert
I mention it for the record, because I think you need a license to redistribute it (it is free for personal use otherwise).
我在传真页面上遇到了同样的问题。
我在 php 中使用 Imagick,这个命令修复了它的外观。
我没有看到任何使用“gs”的阈值选项,但转换可能也适合您。
I ran into the same problem with fax pages.
I was using Imagick in php and this command fixed the way it looked.
I didn't see any threshold option using 'gs' but convert may also work for you.