Unit 2 – Pixels, Images, and Adobe Photoshop - CS++

Learning Objectives

After completing this unit students will be able to:

Identify various image file types
Explain the difference between raster and vector images
Provide examples of where raster images are appropriate versus where vectors make more sense
Explain what pixels are and how they create some (but not all) digital images
Explain how colors are stored via red, green, blue (and sometimes alpha) values
Summarize how color images use binary and hexadecimal systems to store information
Approximate a color based on its six-digit hex code
Modify existing images in a photo editor
Create images and graphics from scratch
Explain how different file types can be optimized for different applications
Demonstrate how to programmatically create images

Additive Color – a color model where no light is black and the combination of all light is white, like RGB
CMYK – color model used for printing. Stands for cyan, magenta, yellow, and black (key), where the number associated with each letter is the percentage of each color used
Graphical User Interface (GUI) – an interface that uses images to represent a system’s folders and files
Pixel –short for picture element. The basic unit of color on a computer display
Pixelation – when individual pixels are too large and the image begins to look blocky
Raster – an image format that represents data in a grid of dots or pixels
RGB – color model used for most monitors or screens. Stands for red, green, and blue, referring to the color of light
Subtractive Color – a color model where no light is white and the combination of all light is black, like CMYK
Text-Based Interface – an interface purely made up of text input from the user
Vector – an image format that represents data through a combination of points connected by lines and curves