Understanding Color Spaces and Color Models
Processing images is as important as capturing them since it will help you to reproduce the colors you captured with your camera.When you learn start learning image processing, you will come across various terms like, color spaces, color models, adobe RGB, sRGB, LAB color, ProPhoto RGB etc. But most people ignore these terms and move on with their workflow. However, it will cause unexpected results like loss of colors when you view the images in websites or someone else’s monitor. You might face a situation that the colors you see on your monitor, or on the back of your camera, is not what you see when you publish those photos in the web. This is due to improper color management. So, in this article I am going to give you a brief idea about various color models and color spaces in digital photography.
What are color models?
Color models are used to convert colors into numbers in digital photography since digital photography works representing various colors are numbers. Understanding various color models will help you to convert one model to another while preserving the colors.
What are the different types of color models?
- RGB: It uses the primary colors — Red, green and blue — to produce all colors. It is based on adding light. Digital cameras and monitors display RGB colors.
- CMYK: It is based on subtracting light. It uses cyan, magenta, yellow and black.
- LAB: It has more colors than the above models. It is used as reference color model when you convert one model to another — say, RGB to CMYK or vice versa.
What are Color spaces?
It is an execution of the color models. So there will be various color spaces for a particular color model. sRGB, Adobe RGB and Prophoto RGB are the color spaces of the RGB color model. Each of them differs from the number of colors they can represent. This is the order of the number of colors each models represent: Prophoto RGB> Adobe RGB> sRGB. The video below explains the difference between the two colors spaces — Adobe RGB and sRGB.
What are working spaces?
Working spaces are color spaces used for image editing and processing. Photographers use larger color spaces for image processing since they provide a wide range of colors. Adobes RGB, Prophoto RGB, CIELAB are some of the working spaces. Adobe RGB is ideal for working in 8 bit mode and prophoto RGB is ideal for working in both 8 bit and 16 bit mode. sRGB, which is the smallest color gamut, is not suitable for image processing.
There is another term called ‘delivery spaces’. It is used for transferring images — from one person to another, publishing in web etc. sRGB is one such color space. Usually, web browsers don’t have much color management. They display only sRGB color space. So if you save an image in adobe RGB or to a higher gamut (space), some colors will be muted when you view it in a web browser or monitor which displays only sRGB color space.
Here is a comparison of ProPhoto RGB, Adobe RGB, and sRGB.
DSLRs can capture images in either sRGB or Adobe RGB. So if you want to capture more colours, capture in Adobe RGB. You can always process your images from a large colour space to a small one (say, adobe RGB to sRGB), but not the other way around.
Knowing various color profiles and its uses will help you in a better colour management. You can convert one color space into another while preserving and/or reproducing the colours you captured. Make sure your monitor, web browsers, and image processing software(s) are properly profiled.