We will be undergoing scheduled maintenance on May 20th, 2013 at 02:00 GMT.
Adobe Photoshop 7 Tutorials
Color Modes / Color Modes Basics
Visitors to VTC.com will be able to view all introductory videos for each training course.
Free Trial Members will gain access to first three chapters for each training course.
Full Access Members have full access to VTC.com�s entire library of video tutorials.
Learn More
Subtitles of the Movie (Adobe Photoshop 7 / Color Modes / Color Modes Basics)
Ok and now for a quick test. What do you notice that is different among these three images? Well actually, to the untrained eye, not a lot except one looks like it's in black and white and the other in color. But in fact there is a lot that's different. And in this lesson I want to talk about color modes or color models. This particular image that I have selected of my dandelion says RGB in the title bar, and this one which looks very much like it says CMYK in the title bar. And this one says gray. And you might derive from it that this is a gray scale version of my color image, and you'd be correct. Another thing I want to point out about my RGB image here is the file size - 5 1/2 megabytes. Now RGB means that this particular image is made up of 3 channels of information - red, green and blue data. So I'm going to go to my window menu and choose channels. And I'm going to make my channels a little bit larger, that is these thumbnails, and go to the palette options and choose this size of my thumbnail image. And what I want to point out here is that my RGB image is made up of, as I said, 3 channels. Or there is my red information. And notice that this information is actually gray scale data and you can think of it as being pushed through colored filters. So this information is being pushed through a red filter, this gray scale information is pushed through a green filter, and this gray scale information for my blue component is pushed through a blue filter. Combined creates the full color image - RGB. Now it's also important to understand that even through it looks like we have four channels here We really only have three channels, and this RGB composite channel is a convenient way for us to see the image in full color. But the computer thinks of this as three channels worth of data. If I click on my CMYK image, notice that I actually have four channels worth of data. Now you need a CMYK image for offset printing, because that is a subtractive color model. So this is a different type of color model needed for most offset printing. Also notice that my file size is a little bit larger, because I have an extra data channel's worth of information. So here's my cyan plate, magenta plate, yellow plate and black plate. The black is called 'K' in the CMYK model so as not to confuse black with blue as in RGB - red, green, blue. Finally, we have a gray scale version, and notice when I select that and make this the active document that this is a very small file size - 1.83 megabytes in size. And also notice that my gray scale image only has one channel's worth of data. So I can make a red, green, blue image from three essentially gray scale data channels combined - pushed through a red filter, green filter and a blue filter to create my full color image. So here is a gray scale document, and as I mentioned look it's exactly 1/3 the file size of my RGB image. Or another way to think of that is that my CMYK image, which has 4 channels worth of data is 4 times as large as my gray scale image, which only contains 1 channel worth of image data. And since there is only one channel's worth of image data, notice that there is no composite channel for us to choose from. Well how do I create this effect? I'm going to show you and it's fairly straightforward. So what I did is I opened up my dandelion image, went to image menu>duplicate to create an exact duplicate of this image. It just adds the name and copy and whatever the number is. I'm going to zoom-out a bit, and I went to the image menu mode. And from this submenu, I chose a different color mode for my particular image. And as you saw, we were just talking about RGB, CMYK and gray scale. So these are the three basic most popular image modes that are used over and over in various imaging workflows. Such as workflows for the World Wide Web - well the World Wide Web is designed to be seen on your computer screen. And your computer screen is an RGB output device. If we were printing this picture in a book or magazine, we would need a CMYK image. So I'd want to convert that to CMYK, which I already did. Or if you were printing it on a black and white printer, you might need a gray scale image. So it's easy enough to take an RGB image, and go to image mode and in this case I'll choose gray scale and click ok. And it just collapses all my color information together to create a gray scale image.
Tutorial Information
| Course: | Adobe Photoshop 7 |
| Author: | Andrew J. Hathaway |
| SKU: | 33329 |
| ISBN: | 1889347272 |
| Release Date: | 2002-09-05 |
| Duration: | 11 hrs / 152 lessons |
| Work Files: |
Yes |
| Captions: | No |
| Compatibility: |
Vista/XP/2000, OS X, Linux QuickTime 7, Flash 8 |
VTC Sign up & Benefits
- Unlimited Access
- 81,350 Video Tutorials (14,200 free)
- Video Available as Flash or QuickTime
- Over 715 Courses
- $30 for One Month Access
- Multi-User Discounts Available
