Graphics Programs Reference
In-Depth Information
ChAPteR 3
digital Imaging
Fundamentals
My experience with teaching
people who already have a good working knowl-
edge of Photoshop has been that they are often confused by fundamental digital
imaging concepts. How is color represented in channels? What is aliasing? What
does bit depth really mean? What is the relationship between canvas size, image
size, and resolution? Should I use RGB, CMYK, or Lab color? No matter whether
you are an absolute beginner or already have some Photoshop experience, this
chapter will answer all of these pressing questions and many more.
Working with pixels
Understanding color
Storing data
Setting document size and resolution
Working with Pixels
After many years of working with digital images, I still marvel at the fact
that cameras somehow magically convert light into numbers. This digital
alchemy boils down to recording myriad blocks of color, better known as
pixels. In the following sections, you will learn the benefits of maximizing
megapixels, how to choose the correct pixel aspect ratio for the kind of
work you are doing, how to deal with aliasing, and finally, how to navigate
through millions of pixels with ease.
Certification
Objective
Maximizing Megapixels
Every year manufacturers seem to produce cameras that can capture more
pixels. Modern sensors capture so many pixels in every photo that the pixels
number in the millions (megapixels). Figure 3.1 shows a photo captured with
a Panasonic Lumix 5-megapixel point-and-shoot camera. Figure 3.2 shows
the same scene photographed with a Canon EOS 5D Mark II 21.1-megapixel
digital single-lens reflex (DSLR) camera.
