It's really funny...(GIMP & CMYK) (zz)

drsu

转载，从 http://cyrilleberger.blogspot.com/2006_10_01_archive.html

给个Abstract:
让gimp支持CMYK是浪费开发者的劳动，因为世界上绝大多数的人都用不到CMYK。
即使你认为自己需要CMYK，但实际上你根本用不到那玩意。

-------
... wether a graphics application support CMYK or not, each time there is an article about this application, there is a lot of comments around CMYK. Each time, the gimp has released a new version, someone would ask "do this,at last, support CMYK ?", or if the question "what application do you miss on linux ?" is raised, someone will answer photoshop because of its support of CMYK.

So now, krita supports well CMYK since 1.5 (actually some CMYK support was introduced in 1.4, but as a demo), Monday, we have release a new version, and I can see some comments about how useless it is to support CMYK (wether it is on slashdot or the dot).

I am thinking that the emergence of the opinion about the uselessness of CMYK, has start, recently, by an interesting comment of Nathan Willis answering someone who was wondering if GEGL will bring CMYK support to the Gimp. And I think he is correct, in 99% of the use case, users won't need CMYK at all.

So, is CMYK really the reason preventing people to use Open Source image editors ?

While CMYK (Cyan Magenta Yellow blacK) inks are used by all color printers, all home and business printers do the conversion from RGB alone. Which means, that, most of the time, if you create an image in krita (or photoshop) in CMYK, you will gain nothing, because krita will have to convert it to RGB before printing!

So useless feature ? In fact no, some professional printers like, for instance, offset printers takes CMYK as input. When I was still studying in engineering school, I took care of editing and printing the student newspaper, and we were using duplicators (we had much more modern version...), we had two of those machines, a one-cylinder duplicator (which could create the master) and a two-cylinders one (but which was requiring the first one to create masters), we were able to emulate CMYK printing, by printing twice with the two-cylinders machine, but as the master could only be created one at a time, we needed a CMYK capable application to do manually the printing.

That's why, Marc and Marie are the only two people who need a CMYK editor. Marc is working for a professional printing service which own printers whose drivers works in CMYK (assuming such a driver exist on linux...). And Marie is an artist, drawing original artwork from scratch and she ask Marc to print them. While John is a photograph, he also send pictures to Marc for printing, but it's camera creates RGB images, so there is no difference if he transform the image himself, of if he gives Marc directly the RGB images. For Marie, CMYK editing is important, because it will give her the most control on the resulting image, mostly because C=M=Y=100% B=0%, and C=M=Y=0% B=100% is the same color, black, but when printed, the second one will looks better than the first one. But all other people in the world are in the same position as John, they don't care about CMYK.

So except for Marc and Marie, CMYK is not the reason why people will choose Photoshop over the Gimp, or Krita over the Gimp. Supporting CMYK is a nice feature, that some people need, but it's not breathtaking and it's far to be the most useful feature of an image editor.

DoDo

呵呵，对于普通的用户来说，CMYK 还是 RGB 根本无所谓，价钱才是最重要的，我不可能为了偶尔该该照片就掏银子去买 Photoshop。我想对于大多数个人用户来讲，开源软件是比商业软件更加合适的。

four

说来说去，对于专业领域，gimp 太弱；对普通用户，gimp 又太繁。

关于cmyk，摘 Grokking the GIMP 的一段

There are also significant advantages to CMYK when doing color correction on an image that will end up in a printed format (see, for example, [6]). The most significant is that the range of colors, known as the color gamut, that can be produced with inks is significantly smaller than what can be created on a color monitor. Thus, it isn't sensible to invest a lot of time working on an RGB image only to convert it to CMYK for printing at the end. This will more than likely produce many out of gamut colors. When the final result is a printed image it is more sensible to convert to CMYK before performing any color transformations.

stephenwong

所以像我这种专业的图形工作者就只能真金白银去买 MacBook 和 Photoshop 了。除此以外再多解释也是无谓的，因为 GIMP 给不了我需要的，而我需要的可以让我的钱包鼓起来 —— 这就是绝大多数“普通人”都无法做到、或者没有必要去做的一件事。

So, it's really funny......

stephenwong

Post by four
说来说去，对于专业领域，gimp 太弱；对普通用户，gimp 又太繁。

关于cmyk，摘 Grokking the GIMP 的一段

CMYK 的色域比 RGB 更大，在处理大画幅照片或海报时不容易丢失色彩细节。
这直接决定照片或海报表现上的层次感。

相信对普通用户而言，这些细节会很让人“费解”，所以才会有 LZ 一文。

－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－

退一步说，GIMP 建立的初衷是制作 GNOME 的 widget 。三岁定八十。

kite

不是说RGB的色域比CMYK大吗？CMYK只是比较适合纸张等印刷吧？

tjzero

不论你作什么设计，只要不是电子媒体，就需要cmyk的

       rgb   r ＊ g ＊ b =颜色数量

       cmyk c*m*y*k =颜色数量

颜色数量应该是  cmyk 大于rgb ,hlv ,hls 大于yuv大于 bw的

还有颜色是多少位数的16bit 10bit 8bit

所以说用gimp还是非常非常初级的东西，根本没法和ps相提并论，gimp对于开源只是有与没有的关系，

waq

GIMP应该考虑支持专业的应用！不应该“剥夺”专业用户使用开源软件的机会嘛。
支持GIMP，但是不支持只给普通用户使用的观点

mrkissinger

Post by waq
GIMP应该考虑支持专业的应用！不应该“剥夺”专业用户使用开源软件的机会嘛。
支持GIMP，但是不支持只给普通用户使用的观点

应该说，没有人“‘剥夺’专业用户使用开源软件的机会”，专业的开源软件正是您这样的专业人士写的，如我等普通用户，虽知道点编程的皮毛，对阁下的专业却基本一无所知。
所以，开源软件向专业领域迈进，不能缺少阁下的鼎力支持。

hooey

这篇 blog 的意思其实是大多数人用的打印机 (非常专业的除外) 虽然用的是 cmyk 的墨水，但是只接受 rgb 的输入，这种情况下处理的时候用 cmyk 跟 rgb 没有区别，去看看当时 krita 宣布支持 cmyk 的时候 ./ 跟 dot.kde.org 上的评论就知道了。