Billmeyer and Saltzman's Principles of Color Technology, 4th Edition

Chapter 10Color Imaging

The first color image, a tartan ribbon, was taken by Sutton in 1861 for a lecture given by Young (Cat 2013). The image was used to demonstrate trichromacy. Advances since that time have changed our cultural landscape including slide and print films, movie film, television, digital photography, digital printing, and digital cinema. Today, color imaging is ubiquitous where each cell phone contains a camera and display. Color consistency is excellent where images can be viewed on different phones, different computer displays, and printed on a variety of printers without large degradations in color quality. The consistency is a result of using colorimetry as a common language, developing transformations between device coordinates and colorimetry, and creating an imaging architecture to facilitate these transformations.

The Image

The properties of a digital image include dimensions, resolution, bit depth, file type, color mode, and color encoding (color management). We can think of a digital image as a piece of graph paper. Each square is called a pixel (a shortened form of “picture element”), and the number of squares on the sheet of paper defines the resolution, shown in Figure 10.1. Digital cameras are marketed according to their total number of pixels. A 24‐megapixel (mpixel or MP or M) camera has 24 million pixels, usually arranged as 6000 pixels in one direction and 4000 pixels in the other direction: 6000 × 4000 = 24 000 000. Our numerical system is ...