|WikiProject Color||(Rated C-class, High-importance)|
- 1 Misleading article
- 2 Seperation images
- 3 Mixing colors and screening
- 4 Fix this text anyone with more patience than I to explain why it is wrong
- 5 Inverting?
- 6 FM screening
- 7 Stochastic screening
- 8 Improvements/title change?
- 9 Splitting/Renaming
- 10 Revision/elaboration suggested for history of color printing
- 11 Grammar Problems
The values on your chart look fine. They would both produce black. So no color changes would occur. --Dkroll2 18:05, Dec 27, 2004 (UTC)
The content of the article is about CMYK color printing. Shouldn't either the title be changed and/or the article merged, or the article itself rewritten to provide an overview of all methods of color printing, including multi-block woodcut, chromolithography, screen printing, etc.? —Preceding unsigned comment added by 220.127.116.11 (talk) 08:57, 8 October 2007 (UTC)
- Yes, this article is actually about four-color process printing. An actual article about color printing would contain information on the different techniques of color printing used over the centuries, and link to each technique for people interested in the details. Shinobu (talk) 00:05, 7 December 2007 (UTC)
- And CMYK color model covers the same material as this article, but it is better referenced, dosn't use suspect images, and is generally better, although I'm not sure if I like the title of that article. The colour model is has more to do with the mathematical transformations between different representations of colour, while the linked article is actually about process printing. Shinobu (talk) 00:44, 7 December 2007 (UTC)
The seperation images are great. Any chance of getting an image of the final product besides that super-grainy one at the end? I think it'd be incredibly useful. :-) — Frecklefoot | Talk 17:34, Dec 29, 2004 (UTC)
I like the separation images too, but should the last image in the separation series look so sharp? Maybe it would look better if a filter was run over the final image to simulate a composite CMYK screen so it looked more like a printed image? addesso 06:36, 23 Apr 2005 (UTC)
Mixing colors and screening
The sections on halftones and screening are good, but they really treat only the subject of reproducing photos, not other art. It's also incorrect to say that colors can only mix in halftones. I can print solid yellow and cyan in the same place on the paper to produce a "kelly green." In short, some additional information and clarification is needed or this article is somewhat and incomplete and possibly misleading. DavidH 00:58, July 12, 2005 (UTC)
This sentance I pasted below, in the article is so not good in so many ways. I'm too old and tired to write the pages of explanation it would take to justify its deletion. Perhaps some "Wiki" can assist here...?--Dkrolls 12:49, 15 May 2006 (UTC)
"Today's digital printing methods do not have the restriction of a single color space that traditional CMYK processes do. Many presses can print from files that were ripped with images using either RGB or CMYK modes. The color reproduction abilities of a particular color space can vary; the process of obtaining accurate colors within a color model is called color matching.
Fix this text anyone with more patience than I to explain why it is wrong
Summary: "digitally scanned" is meaningless in this context. Wikipedians are crazy addicts who ruin articles. The images I uploaded are copyright violations. Shinobu (talk) 00:11, 7 December 2007 (UTC)
Here is the sentance from the article:
"The process of color separation occurs when the original artwork is digitally scanned and separated into red, green, and blue components. Before digital imaging was developed, the traditional method of doing this was to photograph the image three times, using a filter for each color. However this is achieved, the desired result is three grayscale images, which represent the red, green, and blue (RGB) components of the original image:"
Here, I will begin: 1. The words "digtally scanned" have no actual meaning. Unless some new magical technique other than capturing the image data at each point through red, then green, then blue filters had been replaced by some new method with the advent of what we call a "scanner" Just because the capture device is no longer silver-halide, and now each data point is assigned a numerical value, does not allow the words "digital scanning" to be any more appropriate in this day. (p.s. yes, I'm aware of multi-spectral scanning. Yes, I know that mosaic arrays don't capture RGB at every point, blagh blagh, just sombody fix this article. Golly Wiki's are really addicts. I am gonna give this wiki stuff up for good. It's too addictive, and peolp jsut continually put bad info over good. I realize it's just enthusiasm, but it is dissapointing when you had discussions through Wikipedia with color scientists from across the globe until an article is close to pretty darn good, and then 2 years later it looks like someone started over, and all they had was a 6th grade education, or maybe just a massive ego. God bless you all. I gotta get out of here or I'll get pulled in again!
p.s. all the photos of the separations I made around 2004. You should redo them all since I think I was wasted and the origianl image of the girl may be a test image from Kodak, or Fuji, etc. Start with an image that has many colors, and has some monitor colors in it, like chartruse green, so when you talk about the CMYK it will demonstrate the gamut compression. The halftone screens are a great idea, but there is not enough area to even make out that the image exists within those huge dots. Make the dots just big enough so they can be seen, then draw a magnifying glass over a portion. You know what I mean. Go for it you "Wiki" crazy's.
Oh, yeah, and don't use a photograph. The artwork repro folks get mad. Maybe start with a photo and then make it look like a painting in Photoshop, but don't forget to add that splash of vivid monitor green color.--Dkrolls 13:27, 15 May 2006 (UTC)
If inverting the RGB channels gives the CMY channels, why do the CMY separation pictures look completely and utterly different from the inverted RGB pictures?
- Because they are inverted? I mean, the images look correct to me. Shinobu (talk) 23:35, 6 December 2007 (UTC)
On the subject of inverting, this article says "When a negative image of the red component is produced, the resulting image represents the magenta component of the image.". It seems pretty clear from symmetry arguments that that statement can't be true, and should be "cyan" rather than "magenta". The same mistake is made three times (magenta is the inverse of green, and yellow is the inverse of blue). Before I go in and change this, I'd quite like someone else to check my reasoning, though! Steev wilcox (talk) 09:49, 15 January 2009 (UTC)
Removed from the article:
Digital imaging technology has also given rise to new approaches to the screening process. The best-known is stochastic screening or FM screening (frequency modulation, contrasted with the "amplitude modulation" or AM screening of the conventional screening described above). Because the dots are the same size and randomly placed, the moiré effects that are generated by traditional half-tones are eliminated. The best quality of all results from combined screening, in which the mid-tones are generated by stochastic screening, but the extreme light and dark tones use AM screening. 
A side benefit of stochastic screening is the ability to obtain a wider gamut of colors using additional inks such as orange or green (hexachrome). Due to the high resolution of the screen, using computer to plate imaging gives optimal results.
Stochastic screening or some hybrid of traditional linescreen and stochastic has become the standard screening method for many packaging applications.
Hybrid Screening, developed as a graduate thesis at the Rochester Institute of Technology in 1997 , allows for FM dots to be used on detailed areas of an image, whereas conventional dots are placed on flat areas. The computer algorithms also create smooth transitions between AM and FM dots, requiring no randomness at all to be added to the image.
This suggests computer assited screening has something to do with frequency modulation. However, if you read the relevant artiles, you will notice that the two have nothing in common. Please have a look at dither if you really want to know how computer assisted screening works. Shinobu (talk) 00:00, 7 December 2007 (UTC)
<nowiki>Insert non-formatted text here<nowiki>Insert non-formatted text here<nowiki>Insert non-formatted text here<nowiki>Insert non-formatted text here<nowiki>Insert non-formatted text here<nowiki>Insert non-formatted text here--18.104.22.168 (talk) 18:25, 16 December 2008 (UTC)</nowiki></nowiki></nowiki></nowiki></nowiki></nowiki>== We will need new demo images ==
Somebody made the point that this article should be retitled to focus on process color printing, since that's mostly what it is. Sounds OK to me, anyone else? I'd rather not have a massive article that covers all printing methods in one place. This one could link to the CMYK color model article too, but printing methods are separate from the color model, so I think two articles is still appropriate. DavidH (talk) 00:06, 9 December 2007 (UTC)
- This digression into color theory really kills the lead graf.
- Any natural scene or color photograph can be optically and physiologically dissected into three Primary Colors, red, green and blue, roughly equal amounts of which give rise to the perception of white, and different proportions of which give rise to the visual sensations of all other colors. The additive combination of any two primary colors in roughly equal proportion gives rise to the perception of a Secondary Color. For example, red and green yields yellow, red and blue yields magenta (a purple hue), and green and blue yield cyan (a turquoise hue). Only yellow is counter-intuitive. Yellow, cyan and magenta are merely the "basic" secondary colors: unequal mixtures of the primaries give rise to perception of many other colors all of which may be ::considered "tertiary."
- This is fine information when the article gets to the "how" of color printing. It can this be moved lower. If no objections, I'll do it.
I agree that this should be moved somewhere below, though for a different reason. I don't understand why a generic description of the RGB color model, which is used for screen display, is found at the top of a page about color printing, which is based on different models? Also, what do you mean by "yellow is counter-intuitive" and "basic" secondary colors? Maybe what you wanted to say is that color printing is based on the CMY color model, and these three colors happen to be secondary colors in the RGB model? Kileytoo (talk) 08:20, 13 March 2015 (UTC)
Virtually all the comments on this page over the years have complained that this article deals only with a particular modern process. I have now begun to add a "History of" section, still very incomplete I know, and at some point I think much of the detail in the original version should be split off to a more specific title, with just a summary left here. Other modern processes need adding here, I don't know much about these - any help, and comments, welcome. Johnbod (talk) 18:00, 29 May 2010 (UTC)
Revision/elaboration suggested for history of color printing
The historical aspects of this article need further revision and could benefit from substantial elaboration. Most of my comments here refer specifically to the section "History of color printing." Aside from the sign-posted lack of in-line citations, this article would benefit greatly from more authoritative historical sources. A good starting point could be the references section of Wikipedia's "Printing" article, or even the bibliography of what I presume to be the main source of historical information for this article, Bamber Gascoigne's book, How to Identify Prints: A Complete Guide to Manual and Mechanical Processes from Woodcut to Inkjet, 1986 (2nd Edition, Thames and Hudson, 2004). The paucity of historical sources probably explains the other main flaws of this section, namely its inadequate periodization (e.g. when were "early" methods of color printing employed? When did Jacob Le Blon develop his method?); a general disinterest in explaining the development of color printing in relation to other technologies such as mechanical printing or chemical dyes; and its geographic imbalance (there is excessive discussion of undated stages of Japanese color printing when compared to the discussion of Europe and China). Incorporating sources more concerned with the historical development of color printing should fix these problems.
A number of points could be elaborated. Aside from greater discussion of developments in European and Asian color print technology, this article could engage its broader historical context and importance. In particular, the ties between color print technology and the development of consumer cultures in Asia and Europe could be highlighted here. In addition, color print technology's ties to the development of magazines may be worth discussion. While the two illustrations are good examples of 19th century color printing in Europe and Japan, are there any examples from earlier periods that illustrate one of the methods discussed earlier in the article?
With the insertion of a history section, it may be worthwhile to re-organize the article. What distinguishes "Today" from "Modern process"? If the difference is the development of color print technology in more recent years, then these developments should also be dated. As it stands, it is unclear why these two sections should be separated.
Finally, there are some awkward and run-on sentences in the historical section that could use revision (e.g. "In Japan color technique, called nishiki-e in its fully developed form, spread more widely, and was used for prints, from the 1760s on"). —Preceding unsigned comment added by HIST406-10smoura (talk • contribs) 18:17, 2 October 2010 (UTC) --HIST406-10smoura (talk) 18:29, 2 October 2010 (UTC)
In Modern Printing - Color Separation process, it says "However this is achieved, the desired result is three grayscale images, which represent the red, green, and blue (RGB) components of the original image." This does not make sense. I do not know what the original author was trying to say - I know nothing of this topic and merely spotted this. Could someone please edit this to make it make sense? Awesomeshreyo (talk) 19:32, 22 January 2015 (UTC)